Dialysis Vascular Access

Nephrology Dialysis Transplantation 29 (Supplement 3): iii246–iii262, 2014 doi:10.1093/ndt/gfu156 DIALYSIS VASCULAR ACCESS SP522 OBSERVATIONAL STUDY OF SURVEILLANCE BASED ON THE COMBINATION OF ON-LINE DIALYSANCE AND THERMODILUTION METHODS IN HEMODIALYSIS PATIENTS WITH ARTERIOVENOUS FISTULAS Introduction and Aims: On-line dialysance (Kt) and thermodilution (BTM-Qa) methods could be important components in vascular access monitoring programs. This study evaluated the efficiency of these two methods in reducing the thrombosis rate and access-related costs compared with a historic control group. Methods: We studied 148 long-term hemodialysis patients with arteriovenous fistulas (historical control group, n = 74) for 2 years. During the study period, the indications for vascular treatments were the Kt reduction ≥20% with respect to baseline values or Qa less than 500 mL/min (or a decrease in flow > 20%). Differences between the Qa and Kt groups were tested using Student’s T-Test or the Wilcoxon test, as appropriate. The χ2 test was used to analyze the angioplasty and thrombosis rates compared with the historical control group. A P-value ≤0.05 was considered statistically significant. Results: During the study period, we detected 16 cases of significant vascular access dysfunction. The Kt value after vascular treatment was 71.1L (59L; P = 0.001) and BTM-Qa was 1218.6 mL/min (519.7 mL/min; P = 0.001). Compared with the control SP522 Figure 1: Kt (L) and BTM-Qa (mL/min) before and after endovascular (stenosis) and proximal reanastomosis in radiocephalic AVF group, the thrombosis rate was 0.027 vs 0.148 episodes/patient-year (P = 0.009) and the total access-related cost was €22,293 vs €47,467 (P = 0.033). Conclusions: This study suggests that a combined monitoring program based on Kt and Qa-BTM represents an effective screening method that significantly reduces the thrombosis rate and economic costs of vascular treatments SP523 SP522 THE TIMING OF DIALYSIS ACCESS SURGERY AND DIALYSIS INITIATION IN SOUTH WEST WALES: IDENTIFYING PATIENTS WHO NEVER USE THEIR ACCESS Pramod Nagaraja1, David Rees2, Tareq Husein1 and James Chess1 1 Morriston Hospital, Swansea, United Kingdom, 2Morriston Hospital, SWANSEA, United Kingdom SP522 Introduction and Aims: Published guidelines recommend planning for dialysis access in CKD patients when estimated GFR is between 15 and 30 ml/min. The timing of access surgery depends on the rate of decline in renal function and the initiation of dialysis therapy depends on symptoms and other complications of advanced CKD. In this retrospective analysis, we analysed the timing of dialysis access creation and initiation of dialysis. We also aimed to look for factors which help in identifying patients who never started dialysis after access creation. Methods: The setting was a large regional renal unit serving a population of approximately 875,000. From an electronic database, all patients who underwent a definitive first access procedure between January 2006 and December 2010 ( prior to starting dialysis) were identified and their data collected. eGFR was calculated using the 3-point MDRD formula. Follow-up was from the date of access creation until initiation of dialysis, death or 31/03/2013. Results: During the study period, 495 patients underwent at least one access procedure- 424 arteriovenous (AV) fistula or graft and 71 PD catheters. There was an increase in the number of procedures undertaken year-on-year, mainly due to an increase in AV procedures. Median follow-up time was 185 days (range 1 - 2518) from access creation. The mean eGFR just prior to access creation was 12.4±4.6 ml/min © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 Néstor Fontseré1, Gaspar Mestres1, Marta Burrel1, Marta Barrufet1, Xavier Montaña1, Marta Arias1, Raquel Ojeda1, Francisco Maduell1 and Josep M. Campistol1 1 Hospital Clínic. Universidad de Barcelona, Barcelona, Spain Abstracts Nephrology Dialysis Transplantation SP523 COMPARISON OF FACTORS BETWEEN PATIENTS WHO DID AND THOSE WHO DID NOT START DIALYSIS Age in years, Mean±SD Gender, males Systolic BP at access creation, Mean±SD eGFR prior to access creation, Mean±SD Prevalence of diabetes mellitus SP524 Started dialysisn = Not started dialysis n 367 = 122 p 65±15 67% 143±20 72±15 67% 137±19 <0.001 0.90 0.01 11.5±3.7 16.1±7.9 <0.001 36% 42% 0.21 GENOTYPE POLYMORPHISMS OF DIMETHYLARGININE DIMETHYL AMINOHYDROLASE 1 (DDAH1) ARE ASSOCIATED WITH RESTENOSIS OF VASCULAR ACCESS AFTER ANGIOPLASTY IN HEMODIALYSIS PATIENTS Chih-Ching Lin1,2 and Wu-Chang Yang1 1 Taipei Veterans General Hospital, Taipei, Taiwan, 2National Yang Ming University, Taipei, Taiwan Introduction and Aims: Elevated plasma asymmetric dimethylarginine (ADMA) has been reported to be associated with restenosis after percutaneous transluminal angioplasty (PTA) of AVF in hemodialysis (HD) patients. Dimethylarginine dimethylaminohydrolase 1 (DDAH1) is the major enzyme eliminating ADMA, but the effect of genetic variations in DDAH1 on the outcome of vascular access after PTA in HD patients remained unknown. Methods: We assessed the association between polymorphisms in DDAH1 and vascular access outcome in 473 maintenance HD patients, who were prospectively followed up for one year after PTA for vascular access dysfunction. Eleven single nucleotide polymorphisms (SNPs) in endothelial function related genes were analyzed and plasma ADMA levels were determined at baseline. Results: After adjustment of demographic, access, and risk factors, individuals with high baseline plasma ADMA (>0.9μM) levels had higher rates of re-intervention at 6 months after PTA (74% vs. 53%, p=0.05). DDAH1 rs233112 was significantly associated with increased levels of plasma ADMA levels. Compared with individuals with rs233112 AA genotypes, individuals with rs233112 GA or GG genotypes had higher risks for re-intervention (58% vs. 45%, p=0.003) after PTA at 6 months. In the same multivariate- adjusted model, the clinical factors predicting higher risk of re-intervention at 6 months include current smoker, graft access, and rs233112 GG +GA genotypes of DDAH1 gene (HR 2.302, 95% CI 1.557-3.407). Conclusions: Our study demonstrate that rs233112 GG+GA genotypes of DDAH1 gene predict early and frequent restenosis of vascular accesses after PTA in HD patients. SP525 REDUCED INFECTION RATES IN A DIALYSIS NETWORK WITH A NOVEL SURVEILLANCE PROGRAMME Maryam Khosravi1, Hala Kandil2, Jenny Cross1, Susan Hopkins2 and Sophie Collier2 1 Royal Free & University College London, London, United Kingdom, 2Royal Free Hospital, London, United Kingdom Introduction and Aims:Since January 2010 , a surveillance programme was used in six renal dialysis satellite units comprising a large multi-ethnic city centre network affiliated to Royal Free NHS Foundation Trust. The aim was infection prevention and antibiotic monitoring. We present the first three years of prospectively collected data in this study. Methods:Numerator data was collected on microbiologically confirmed bacteraemias and antibiotic starts per month.Denominator data was collected on the number of patients and their access type in each unit per month.In this network a bundle of infection control measures had been instituted in 2008 including:1.Rolling audits of hand hygiene2.Rolling audits of dialysis catheter care3.Chlorhexidine impregnated exit site dressings4.43% Citrate line locks5.A three-monthly rolling programme of screening for Staphylococcus aureus nasal carriage & subsequent decolonisation was practiced.6.A drive to increase native access ratesThe above data was presented regularly throughout the study period to individual units, the whole dialysis team and the wider trust to improve performance using feedback for shared learning. This also allowed benchmarking between units. Results:During the study period, the line infection rate decreased from 0.73 per 1000 catheter days in 2010, to 0.65 in 2011 and 0.37 in 2012 (r2 linear test of trend=0.9). In the same period native dialysis access rates increased from 64% to 78%.A review of the causative organisms over the 3 years of the study showed a marked decrease in the number of line infections caused by coagulase negative staphylocooci, which would support improved renal catheter care over the study period.The Staphylococcus aureus infection rate fell from 0.12 bacteraemias per 1000 dialysis days to 0.1 in 2011 and 0.08 in 2012 (r2 linear test of trend =1). Audit data showed excellent compliance with the nasal screening programme, with over 95% of patients being screened each cycle.One possible confounding factor that changed during the study was the introduction of the buttonhole technique for accessing fistulas. This was associated with a rise in Staphyloccus aureus bacteraemias in these patients, so routine use of this technique was subsequently stopped. Audit results of hand hygiene and renal catheter care showed good and constant results throughout the study period.Infection rates were not reduced by increased antibiotic prescriptions. The average rate of antibiotic starts per 1000 dialysis days was 1.81 in 2010, 1.90 in 2011 and 1.41 in 2012. Conclusions:We have successfully introduced and maintained an active surveillance programme amongst six dialysis units, which alongside other components of the infection prevention programme has helped to reduce infection rates. SP526 ARTERIOUVENOUS FISTULA OUTCOMES IN THE ELDERLY CKD POPULATION: RESULTS FROM A SINGLE CENTER Daniela Lopes1, Susana Pereira1, Ana Marta Gomes1, Ana Ventura1, Vitor Martins1 and Joaquim Seabra1 1 Centro Hospitalar VNGaia, Vila Nova Gaia, Portugal SP524 Volume 29 | Supplement 3 | May 2014 Introduction and Aims: The number of patients on hemodialysis over 75 years is increasing. KDOQI guidelines recommend the arteriovenous fistula (AVF) as the preferred vascular access for patients undergoing hemodialysis. Once functional, AVF exhibit the best long-term primary patency rate and requires the fewest interventions of any type of access. Most importantly, AVFs are associated with the lowest incidence of morbidity and mortality. The outcomes of AVF in the elderly patients are controversial. The aim of this study is to compare the outcomes of AVF in patients <75 years old (75-group) versus ≥75 years old (75+ group). Methods: Retrospective cohort study of AVF created in our hospital between 2007 and 2012. AVF cumulative patency was evaluated using Kaplan-Meier survival analysis and log-rank test. The follow-up time was twelve months after AVF creation. Statistical analysis was performed using the T test and Chi-Square. A Cox model was used to determine factors associated with AVF loss. The significance level for the models were determined as p<0.05. doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 (range 3.1 - 34 ml/min), and this did not change significantly over time. Mean eGFR in patients undergoing an AV procedure (12.9±4.6 ml/min) was higher compared to those undergoing PD catheter insertion (9.2±3.3 ml/min, p<0.001). During follow-up, 296 (60%) patients started HD, 71 (14%) started PD, 6 (1%) received a pre-emptive transplant, 58 (12%) died prior to starting dialysis and 64 (13%) were still under follow-up having not yet started dialysis. In those patients who started dialysis, the time from access creation to initiating dialysis was a median of 141 days (range 0-1648 days). The mean eGFR at starting HD was 8.9 ml/min and at starting PD was 9.3 ml/min (p=0.47), and this did not change over time. The above results did not change when the analysis was repeated by excluding “crash-landers” (time from registration to dialysis <60 days, n=21). Comparison of factors between those patients who did and those who did not start dialysis are shown in the table.In a sub-group analysis of patients who had complete proteinuria data (n=219), a higher proportion of those with heavy proteinuria started dialysis than those without proteinuria (75% vs. 46%, p<0.001). Conclusions: A significant proportion of patients (25%) in this analysis did not start dialysis after access creation, with 12% of patients dying before starting dialysis. Older patients with lower BP, no proteinuria and a higher eGFR appeared to be the cohort not starting dialysis. These results help in refining our access services by better identifying patients most likely to need dialysis. We aim to further improve this prediction by carrying out a multivariate analysis which includes the slope of decline in eGFR. Abstracts SP527 DEVELOPMENT AND EVALUATION OF IN VIVO ENGINEERED VASCULAR GRAFTS IN A PORCINE MODEL T C Rothuizen1, F Damanik2, M J.T. Visser1, T Lavrijsen3, M A.J. Cox3, L Moroni2, T J Rabelink1 and J I Rotmans1 1 Leiden University Medical Center, Leiden, The Netherlands, 2University Twente, Enschede, The Netherlands, 3Xeltis BV, Eindhoven, The Netherlands Introduction and Aims: Vascular access remains the Achilles' heel of hemodialysis. Tailor made tissue engineered blood vessels (TEBVs) may circumvent the fundamental inconveniencies of synthetic grafts and could offer a suitable alternative. Here we present a tissue engineering approach where the TEBV is grown within the body in a porcine model. Cylindrical shaped polymer rods were developed that upon implantation evoke a controlled inflammatory response culminating in the encapsulation of the rod by a fibrocellular tissue capsule, that can form the basis for a TEBV. After extrusion of the rod and grafting the tissue capsule in the vasculature, it can further differentiate into an adequate vascular access conduit. Methods: Per pig, 8 polymer rods were implanted subcutaneously. After 4 weeks, rods with tissue capsules grown around it were harvested. Per pig, 2 tissue capsules were grafted bilaterally as carotid artery interposition conduits. Patency was evaluated after 1 and 4 weeks by angiography. Pigs were sacrificed after 4 weeks and tissue capsules were harvested and evaluated on tissue remodelling with histological and mechanical analysis. Results: Rods were encapsulated by a thick walled, well vascularized tissue capsule (Fig. A), mainly composed of circumferentially aligned (myo)fibroblasts and collagen I and III and few leukocytes, resulting in a burst pressure of 3948 ± 360mmHg and a suture strength of 5,8 ± 2,2N. Tissue capsules could easily be extruded from the rod (Fig. B) and were all successfully grafted (Fig. C). Patency as assessed by angiography was 100% (8/8) after 1 week and 87,5% (7/8) after 4 weeks. No aneurysms were observed. Time to hemostasis after cannulation with a dialysis needle and subsequently digital compression was <3 minutes.After exposure to flow and strain, the graft wall largely remodelled. The leukocytes present before grafting disappeared 4 weeks after grafting. Luminal area increased accompanied by a 3,25-fold ( p<0.0001) increase in wall thickness and an increased α-SMA positive area from 29,4 ± 3% before grafting to 61,2 ± 3% after grafting ( p<0.0001). Importantly, after 4 weeks a steady state was reached and proliferation staining with Ki67 was completely negative. Interestingly, a substantial portion of (myo)fibroblasts present before grafting differentiated into a smooth muscle cell phenotype. Burst pressure remained stable during grafting (4177 ± 41mmHg after grafting, p=0,11). Conclusions: Using a novel in vivo tissue engineering approach, an autologous TEBV was created with sufficient mechanical strength enabling autologous vascular grafting with a 4-week patency of 87,5%. Future studies should evaluate its potential as arteriovenous graft. SP527 iii | Abstracts SP528 LOCK TUNNELED CATHETERS WITH TAUROLIDINE-CITRATE-HEPARIN LOCK SOLUTION SIGNIFICANTLY IMPROVES INFLAMMATORY PROFILE IN HEMODIALYSIS PATIENTS Néstor Fontseré1, Celia Cardozo1, Javier Donate2, Alex Soriano1, Mercedes Muros2, Mercedes Pons3, Josep Mensa1, Josep M. Campistol1, Juan F. Navarro-González2 and Francisco Maduell1 1 Hospital Clínic. Universidad de Barcelona, Barcelona, Spain, 2Hospital Universitario Nuestra Señora de Candelaria, Tenerife, Spain, 3CETIRSA Barcelona, Barcelona, Spain Introduction and Aims: Mortality and morbidity are significantly higher among patients with dialysis catheters, which has been associated with chronic activation of the immune system. We hypothesized that bacteria colonizing the catheter lumen trigger an inflammatory response. We aimed to evaluate the inflammatory profile of hemodialysis patients before and after locking catheters with an antimicrobial lock solution. Methods: Thirty-one patients in a stable hemodialysis program through tunneled cuffed catheters with 5% heparin lock during the previous 6 months (heparin phase) were enrolled in a study to prospective evaluate of Taurolidine-citrate-heparin lock solution (TCHLS). High-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha (TNFa) were measured in serum, and levels of mRNA gene expression of IL-6, IL-10 and TNFa were analyzed in peripheral blood mononuclear cells (PBMC). Samples were obtained at baseline and again after 3 months’ use of TCHLS. Continuous variables were compared using Student́s T test and categorical variables using χ2 test or Fisher’s exact test when necessary. A P-value < 0.05 was considered statistically significant. Results: The rate of catheter-related bloodstream infections (CRBSI) was 1.08 per 1000 catheter-days in the heparin period and 0.04 in the TCHLS period (P = 0.023). Compared with baseline, serum levels of hs-CRP and IL-6 showed a median percent reduction of 18.1% and 25.2%, respectively (P < 0.01), without significant changes in TNFa or IL-10. Regarding cytokine gene expression in PBMC, the median mRNA expression level of TNFa and IL-6 decreased by 20% (P < 0.05) and 19.7% (P = 0.01), respectively, without changes in IL-10 expression levels. Conclusions: The use of TCHLS to maintain the catheter lumen sterile significantly reduces the incidence of CRBSI and improves the inflammatory profile in hemodialysis patients with tunneled catheters. Further studies are needed to evaluate the potential beneficial effects on clinical outcomes. SP528 Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 Results: In this period 303 patients had constructed AVF, 104 patients had more than 75 years. In the 75+ group with median age of 78, there were 70 male, 39 (37,5%) had diabetes and 9 had heart failure and in 89 patients this was their first hemodialysis access. In the 75- group there were 199 of males, the median age of 62, 96 (48%) had diabetes. The two groups were similar in the prevalence of diabetes, heart disease and the anatomic site of the AVF. In total, there were 127 vs 55 distal AVF (radiocephalic), 71 vs 46 proximal AVF (brachiocephalic and superficialized brachiobasilic) in the 75vs 75+ groups respectively. The only statistical significant difference between the groups was the existence of a previous AVF. In 75- group 60 (30%) patients had an AVF previously comparing to 15 patients in the older group ( p=0.03).When comparing the groups there is no difference in primary failure, 22% in the 75- group and 19% in the 75+group ( p=0.516). There is no effect of gender, diabetes and heart failure on AVF survival, according to age group. During 12 months follow-up the mean survival time was similar in both groups, 11,4 months (75- group, p=0,185) and 10,6 months (75+ group, p=0,451). Also there is no differences in the assisted patency. The overall total procedure rates were 30 vs 17 respectively ( p= 0,821) with 14 vs 8 percutaneous angioplasty ( p=0.891), thrombolysis 6 vs 0 ( p=0.068) and 24 vs 9 had surgical revision ( p=0,313) in groups 75-vs 75+ respectively. Conclusions: In our study we did not find any differences between the two groups in terms of failure to mature, number of procedures or in the cumulative survival. In the elderly, AVF should be considered in patients who have a high chance for a successful fistula and age per se should not be a limiting factor when choosing AVF as the optimal permanent access. Nephrology Dialysis Transplantation Abstracts Nephrology Dialysis Transplantation SP528 SP529 EFFECT OF ETHNICITY AND SOCIOECONOMIC FACTORS ON PRIMARY FAILURE RATE AND SURVIVAL OF SIMPLE ARTERIOVENOUS FISTULAE Anika Wijewardane1, Alexander Murley1, Sarah Powers1, Clive Allen1, Jyoti Baharani1 and Teun Wilmink1 1 Heart of England Foundation Trust, Birmingham, United Kingdom Introduction and Aims: To examine the effect of ethnicity, socioeconomic status and comorbidity on fistula outcomes. Methods: Retrospective review of two prospective databases of access operations and dialysis sessions from 2003-2011. Follow up till 1 March 2013. Primary failure (PF) defined as an arteriovenous fistula (AVF) used for less than 6 consecutive dialysis sessions. AVF survival was defined till the time AVF abandoned. Ethnicity was coded from hospital records. Deprivation index (DI) calculated from postcodes and 2011 census data from Office of National Statistics. Comorbidities were calculated using Charlson Index. Results: 1002 patients were analysed: 619 (62%) had radiocephalic AVF (RCAVF), 303 (30%) had brachiocephalic AVF (BCAVF), 80 (8%) had brachiobasilic AVF (BBAVF). Sixty-eight percent were Caucasian, 25% Asian and 6% Afro-Caribbean. Half (49%) were in the highest DI category and 11% in the lowest. Caucasians were older than Asians and Afro-Caribbeans ( p= 0.0001). In 74%, the fistula was used for dialysis, 21% had PF and in 5% the outcome was unknown. Women had 25% PF compared to 18% for men ( p < 0.009). PF did not differ with ethnicity ( p = 0.28), DI ( p = 0.81), co-morbidities ( p = 0.57) or diabetes ( p =0.78). AVF survival was not significantly different according to gender (logrank test p = 0.33) or DI (logrank test p = 0.87). Diabetics had a worse AVF survival (logrank test p = 0.03). Low comorbid status was associated with better AVF survival (logrank test p = 0.02). Afro-Caribbeans had slightly shorter AVF survival (logrank test p = 0.07). Conclusions: Ethnicity, socioeconomic status and comorbidity had no significant SP529 effect on primary failure rate. Low comorbid status had significantly longer AVF survival and Afro-Caribbeans had slightly shorter AVF survival. SP530 PROTECTION OF AUTOGENIC VESSELS AND USE OF VESSELS STEP BY STEP IN 1420 AV FISTULAS (SHARE OF OVER 25 YEARS EXPERIENCE) Mustafa Esentürk1, Murat Zengin2, Muhlise Dal1 and Nüvit Tahtalı1 Malatya State Hospital, Malatya, Turkey, 2Fresenius MLTY, Malatya, Turkey 1 SP529 Volume 29 | Supplement 3 | May 2014 Introduction and Aims: The aim of long time fistula survives is important for dialysis patients. We have to notice for the points of proper use of cephalic vein. Fistulas must start from distal to proximal and should be used in every possible anastomosis point on arm.In our study we examine 1420 A-V fistulas made by same surgeon. We classified fistulas for a database for further investigations. Methods: We investigate 1420 patients between Feb. 1989 to Dec. 2013.The youngest patient was 12 and the oldest was 95 years old. Awarage was 56.8. 832 (58.7%) were male and 893 (63.0%) were on left hand (non-dominant arm) 1349 were opened by side to side technique. Mostly Brescia_Cimino site were used in 940 (66.3%) patients. 1158 (81.7%) were opened at distal site of the arms and 259 (18.3%) were opened at ante-cubital. Results: KDOQI 2006 guideline increased A-V Fistula usage to over 65%. (2,9,13). According to data from Euclid 2009 83% AVF, 14% CVC and 3% AVG of 5046 patients in Europe. (75% of catheters were permanent and 25% of them were temporary CVC). In our country according to TND datas, 86-88% AVF, 11.2% CVC and 2.9% AVG were used as vascular access. In our study on the last quarter of 2013 at Malatya State Hospital we have 88 (89.8%) AVF 10 (10.2%) in 98 patients. We have notifications on economic use of cephalic veins, carefull vascular mapping before and after surgery (for canulation), starting fistulas from distal to proximal, avoiding from subclavian catheterisations, if done not opening fistulas from that side. By this ways we reach doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 SP529 Abstracts Nephrology Dialysis Transplantation SP530 SP532 HAEMODYNAMIC CARDIAC MODIFICATION OCCURING AFTER HIGH FLOW REDUCTION BY PROXIMAL RADIAL ARTERY LIGATION OF RADIAL-CEPHALIC FISTULA FOR HAEMODIALYSIS Jacopo Scrivano1, Laura Pettorini1, Teresa Rutigliano1, Giuseppino M. Ciavarella1, Luciano De Biase1, Giorgio Punzo1, Paolo Menè1 and Nicola Pirozzi1 1 Sapienza University of Rome, Rome, Italy SP530 sucsses.Some studies reports as two are lower and upper arm for AVF region. (11). We divide arm 4 or 5 area for AVF starting from Snuff-Box, Brescia-Cimino (as distal, middile and proximal) and as last choice ante_cubital area. By this we aime to open at least 4 or 5 AVF at same arm, by using veins step by step ant to increase quality of life. Conclusions: Economic use of vessels on forearm, starting to open fistulas from distal, by 2-3 cm separation to open new fistulas, by that to have at least 4 or 5 fistulas on one arm. Target of catheter usage is less than 10% in the world. We have 27 (8.7%) CVC in 309 (281 90,9% AVF, 1 (0,3%) AVG) patients form 4 dialysis center in Malatya. SP531 MOIST WOUND HEALING OF BUTTONHOLE ENTRY SITE TO REDUCE VASCULAR ACCESS INFECTION Kazuhiko Shibata1, Takahiro Shinzato2, Hidehisa Satta3, Masahiro Nishihara3, Naoaki Koguchi3, Tadashi Kuji4, Seiichi Kawata4, Tomoko Kaneda1 and Gen Yasuda5 1 Yokohama Minami Clinic, Yokohama, Japan, 2Daiko Medical Engineering Research Institute, Nagoya, Japan, 3Toshin Clinic, Yokohama, Japan, 4Yokodai Centrel Clinic, Yokohama, Japan, 5Yokohama City University Medical Center, Yokohama, Japan Introduction and Aims: Inspite of the facts that the buttonhole cannulation method has advantages over the rope ladder method by lesser puncture pain and a longer access vessel life, it has not been taken as the best method of AVF cannulation. This may be due to its higher incidence of infections of access vessels. Using the conventional dry buttonhole entry site treatment method, bacteria-contaminated scab adhere firmly to the buttonhole entry site, and cannot be completely removed before puncture. Such small pieces of bacteria-contaminated scab may be pushed into the buttonhole tunnel tract or subcutaneous tissue during puncture, which may contribute to the higher rate of vascular infection using buttonhole puncture than using rope ladder puncture technique. This hypothesis is supported by the report of Elek et al. that the minimum pus-forming dose for virulent staphylococci is in the order of 2 to 8 million organisms; only a small number of bacteria could be inoculated into the subcutaneous tissue in the rope ladder technique, whereas a large number of bacteria may enter the tunnel tract via small pieces of bacteria-contaminated scab in the buttonhole technique. To solve this problem, we treated the buttonhole entry site with a moist wound healing method after each hemodialysis session to prevent scab formation. Methods: After a hemodialysis session, we placed a small amount of petrolatum album on the buttonhole entry site and covered with an adhesive plaster to keep the site moist even at home (moist wound healing method). Then, we instructed the patients to wash out the scab using a commercially available microfiber cloth at home whenever they wash their hands, and then to apply the same ointment on the site again to keep moist iii | Abstracts Introduction and Aims: AVF induces adaptive modifications of both left (LV) and right ventricle (RV). These modifications might evolve to LV hypertrophy, impaired function of right sections with pulmonary hypertension and high output heart failure. When high flow AVF (Qb>2 L/min/1.73m2), along with increased cardio-pulmonary recirculation (CPR = Qb/CO >20%) exist, its reduction is suggested. As described by Bourquelot, proximal radial artery ligation (PRAL) is effective in flow reduction of distal radio-cephalic AVF (RCAVF). We compared echocardiographic (ECHO) finding before (T0) and 1 and 6 months (T1, T6) after PRAL. Methods: We observed 6 consecutive patients with a high flow RCAVF, increased CPR and symptoms of impaired cardiac function. The patients characteristics are exposed in Table 1.By ECHO we evaluated tricuspid anular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PAPs), right ventricle telediastolic diameter (RV TDD), right ventricle ejection fraction (RV EF) at T0, T1 and T6. Modifications of CPR (Δ CPR) and AVF Qb (Δ Qb) were assessed before and 1 month after PRAL. During preoperative ECHO, a dynamic evaluation of TAPSE before (T0b) and after manual compression(T0c) of AVF anastomosis was performed. Results: Qb was 2,3 ± 0,3 L/min/1,73 m2 at T0 and 1,0 ± 0,1 L/min/1,73 m2 at T1(flow reduction 56 ± 5,2%, p<0,001). CPR was 36,5 ±10,4% at T0 and 18,5 ± 7,0% at T1 (17,9 ± 11,9% CPR reduction, p=0,005). An early (24h) improvement of cardiac functional status was observed in all pts.ECHO parameters are exposed in Table 2.We find a positive correlation (by Pearson’s coefficient) between: Δ TAPSE T0b/T0c and Δ TAPSE T0/T1 (0.84) as well as Δ TAPSE T0b/T0c and Δ TAPSE T0/T6 (0.73); Δ Qb T0/T1 and Δ PAPs T0b/T1 (0.74) as well as Δ Qb T0/T1 e Δ PAPs T0b/T6 (0,66); Δ Qb T0/T1 and Δ RV TDD T0/T1 (0.61) as well as Δ Qb T0/T1 and Δ RV TDD T0/T6 (0.96) Conclusions: After a successful reduction of RCAVF flow, significant haemodynamic changes occur. Our results seems to outline the effect of volume/pressure stress over the SP532 Tab 1: Patients characteristics (legend: CKD: chronic renal disease; ESRD: end stage renal disease) Age (yrs) 67 ± 10 Sex NYHA class Functional status AVF vintage (yrs) 5M1F IV: 1 pt; III: 1 pt; II 3 pts; I: 1 pt 3 ESRD; 2 CKD V K/DOQI; 1 Trasplantation 7±6 SP532 Tab 2: ECHO parameters before and after PRAL (legend: Δ: difference) T0b T0c T1 T6 Δ T0b/T1 PAPs (mmHg) 16,6±5,0 21,5±0,8 22,5±2,5 22,5±3,3 5,6±3,6 (p= 0,03) PAPs (mmHg) 45,8±10,3 36,0±11,6 30,8±6,8 9,5±9,7 (ns) RV TDD (mm) RV EF (%) Δ T0b/T6 5,8±3,6 (p=0,04) 30,1±4,8 29,5±5,9 29,3±4,6 0,6±4,8 (ns) 15±10 (p=0,014) 0,8±5,9 (ns) 56,3±7,9 56,5±12,3 63,5±8,8 0,1±7,1 (ns) 7,1±5,6 (ns) Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 environment. When they visited our dialysis facilities, we observed the buttonhole entry site grossly as well as using an electron microscope before and after scab removal. Moreover, to confirm the effectiveness of the moist wound healing method in preventing bacterial infection, we compared the number of infectious events of the blood access for one year between a group of patients using the conventional rope-ladder puncture technique (n = 143) and a group using the buttonhole puncture approach in which the entry site was treated by the moist wound healing method (n =111). Results: In patients punctured by buttonhole technique, gross examination showed only a small scab that was easily peeled off by pincers at the buttonhole entry site. After removing the scab, no fragments were found around the opening of the buttonhole tunnel tract when the site was observed with an electron microscope. During one-year observation period, blood access infection occurred totally 6 times (5.4%) in patients punctured by buttonhole technique with entry site treatment by the moist wound healing method, and 10 times (7.0%) in those punctured by rope-ladder method. Chi-square test detected no significant difference between two groups ( p = 0.593). Conclusions: When buttonhole entry sites were treated by a moist wound healing method, scabs were completely removed before punctures. Complete scab removal resulted in no difference in rate of blood access infection between buttonhole puncture technique and rope-ladder method. Abstracts Nephrology Dialysis Transplantation right section related to an high flow RCAVF (Δ Qb vs Δ PAPs and Δ RV TDD). The preoperative dynamic manoeuvre during ECHO (Δ TAPSE T0b/T0c vs Δ TAPSE T0/ T1) could represent an adjunctive tool to asses AVF related heart impairment.Further studies are needed to confirm these preliminary results. SP533 THE CONVERSION FROM ROPE LADDER FISTULA CANNULATION TECHNIQUE TO BUTTONHOLE TECHNIQUE DOES NOT INCREASE THE RISK OF FISTULA-RELATED INFECTION AND RESULTS IN LESS COMPLICATIONS AND INTERVENTIONS IN CENTER-DIALYSIS PATIENTS. Wael El Haggan1, Khadija Belazrague1, Sabrina Ehoussou1, Véronique Foucher1 and Magdy El Salhy1 1 Centre de Dialyse ECHO, Laval, France SP533 Systemic fistula-related infection episodes Local fistula infection episodes Needle stick pain (NRS) Pre-needle stick anxiety (NRS) Number of patients using topical anaesthetic Haemostasis duration (minutes) Haematoma occurrence episodes Angioplasty or surgical intervention events Patient’s technique preference SP534 RL 0 0 5. 4 +/- 1. 6 7 +/- 1. 8 10 12.32 +/- 3.36 38 6 0 BH 0 1 1 +/- 0.4 1 +/- 0.7 0 4.1 +/- 1.9 3 0 12 p-value NS NS < 0.001 < 0.0001 < 0.0001 < 0.001 < 0.0001 < 0.0001 < 0.0001 SP535 ARTERIOVENOUS FISTULA FLOW SURVEILLANCE: COMPARISON BETWEEN A NEW HEMODILUITION TECHNIQUE AND COLOR DOPPLER ULTRASOUND Laura Pettorini1, Federica Romitelli1, Loredana Fazzari2, Jacopo Scrivano1, Gianluca Ortu2, Enrico Di Stasio3, Giorgio Punzo1, Paolo Menè1 and Nicola Pirozzi1 1 Nephrology Unit, Sant’andrea Hospital, Rome, Italy, 2Nephrology Unit, CdC Nuova ITOR, Rome, Italy, 3Biochemical and Clinical Biochemical, Sacred Heart University, Rome, Italy Introduction and Aims: K-DOQI guidelines recommend a regular surveillance and monitoring of arteriovenous fistula (AVF) flow (Qa) after creation. The most recommended technique is ultrasound diluition (Transonic), which is nevertheless expensive and unavailable in Italy. Color Doppler Ultrasound (CDU) is another technique recommended for AVF blood Qa measurement, with the limitation of requiring a skilled, experienced operator. In 2008 Tiranathanagui et al. described a significative correlation between Transonic and a new hemoglobin diluition technique (HDT) for Qa evaluation.In our study we have analyzed the correlation between HDT and CDU for access flow evaluation. Methods: We observed 14 patients in hemodialysis (HD) with distal radiocephalic AVF (median age 74.5, 12 M: 2 F, median BMI 25.4 , 79% hypertension, 14% diabetes and 14% cardiovascular disease). Each patient was evaluated with CDU and HDT performed by the same operator.To determine the Qa by the HDT, the lines of HD circuit at priming has been reversed 12 seconds after starting blood pump (300 ml/ min) two samples for Hb were collected. Results: The measurement of the flow by HDT presented a significative correlation with CDU (r2 = 0.807; p<0.001)(fig.1). The median (±SD) flow were measured by CDU and HDT 964 ± 335 and 875 ± 503 ml/min, respectively. Bland-Altman plot comparing HDT and CDU, showed that for AVF flow <1000 ml/min, HDT tends to underestimate Qa of 300 ml/min (fig. 2). Conclusions: The gold standard for arteriovenous access surveillance are considered Transonic and CDU. In our study we have observed that HDT correlate significantly with CDU. HDT has several advantages, being easy to perform and not expensive. Whenever its tendency to underestimate Qa for blood flow <1000 ml/min would be confirmed, the aim of preventing thrombosis through surveillance, would still be preserved.HDT seems to be a reliable alternative for AVF Qa surveillance. Further studies would help in better defining these preliminary results. IMPLEMENTATION OF A “NO DRESSING” PROTOCOL FOR CATHETERS IN A LARGE HEMODIALYSIS CENTER: RECIPE FOR DISASTER Georges Ouellet1,1, Joanne Davis1, Patricia Caron1 and Martine Leblanc1,1 1 Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada Introduction and Aims: In chronic hemodialysis (HD) patients with a catheter (CVC), the exit site of the CVC is routinely inspected, disinfected and cleansed, then covered with an adhesive transparent dressing. Some patients can develop severe pruritus or dermatitis with different types of dressing. The aim of this study is to review the characteristics and outcomes of patients in whom a « no dressing » protocol was attempted. Methods: In patients carefully identified as candidates for the “No dressing” protocol, the CVC exit site was disinfected with a gauze impregnated with a 2% chlorhexidine gluconate/70% alcohol solution for 30 seconds at each treatment, then the exit site was let to dry completely. Results: Twelve (among 375) chronic HD patients (9 males, mean age 76±14 yo, mean dialysis vintage 42±28 months, 5 diabetics) with cuffed tunneled CVC were put on the “no dressing” protocol. Reasons for initiating this approach were: intractable pruritus (11), severe dermatitis (8), recurrent removal of the dressing between treatments (3). The mean duration of the “no dressing” approach was 172±139 days (median 160 days). Reasons for discontinuation of “No dressing” were: cuff extrusion (5), local infection (3), severe sepsis from the CVC (2, with 1 causing death), death (2), transfer Volume 29 | Supplement 3 | May 2014 SP535 Figure 1: Correlation among the methods graphic doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 Introduction and Aims: The buttonhole technique (BH) of access of needle insertion into a single selected site in the arteriovenous fistula (AVF) has proved to be a reliable alternative to the rope ladder technique (RL). However, several retrospective studies have demonstrated that BH technique is associated with increased rates of fistula-associated infection, which had discouraged its use in many units.Aiming at assessing the usefulness of the BH technique in center-dialysis patients, we conducted this prospective study. Methods: Twenty patients receiving haemodialysis via AVF in our center were converted from RL technique to BH technique. All patients (14 men and 6 women) were included and prospectively followed up for one year. In addition to the incidence of systemic and local fistula-related infections, the following parameters were registered: needle stick pain, pre-needle stick anxiety [using 0-10 numerical rating scale (NRS)], the use of topical anaesthetic, the duration of haemostasis after needle withdrawal, haematoma occurrence, the need for angioplasty or surgical intervention, and patient's preference for the 2 approaches. Data were collected for RL retrospectively at the time of conversion, and for BH one month after conversion, then 6 and 12 months later. Results: The preliminary results of 12 patients who had completed the follow-up period are presented in the table. Conclusions: Our results show that the frequency of AVF cannulation-related complications was significantly lower with BH technique compared with RL technique. The conversion from RL technique to BH technique was not associated with significant increase in infection risk. Moreover, all the patients in this report were satisfied and preferred the new technique. to peritoneal dialysis (1). A second attempt of “no dressing” was made in 3 patients for intractable pruritus (median duration 34 days); and was stopped in 2 patients, due to tunnel infection (1) and cuff extrusion with severe sepsis (1). Overall, 9 out of 14 CVC had to be removed because of infection or cuff extrusion, 1 was pulled by accident, 2 were still inserted at patients’ death. Two deaths were attributable to CVC infections. Conclusions: In conclusion, “no dressing” for CVC exit site is associated with an unacceptable risk of infectious complications and leads to poor access and patient outcomes. The “no dressing” approach has been abandoned in our unit. In case of intractable pruritus or severe local dermatitis at the CVC exit site, other strategies should be considered, including reemphasazing the importance of arteriovenous fistula creation. Abstracts Nephrology Dialysis Transplantation SP535 Figure 2: Bland-Altman graphic SP536 COMPARISONS OF CLINICAL OUTCOMES WITH DIFFERENT ANGIOPLASTIC TECHNIQUES IN HEMODIALYSIS GRAFTS Giuliana Loizzo1,2, Sara Maria Viganò3, Giuseppe Bacchini3, Elena Rocchi3, Valeria Sala3 and Giuseppe Pontoriero3 1 University of Bari, Bari, Italy, 2Nephrology, Dialysis and Transplantation Unit, University of Bari, Bari, Italy, 3Nephrology and Dialysis Department Lecco, Lecco, Italy Introduction and Aims:A number of advantages and concerns have been raised for different angioplastic techniques but the comparisons of clinical outcomes are absent, especially for the treatment of hemodialysis grafts’ (AVGs) stenosis. Despite of percutaneous transluminal angioplasty (PTA), that induces a traumatic vessel wall injury, peripheral cutting balloon (PCB) creates microsurgical incisions, through its blades inducing a dilation of the stenosis at lower pressure. The aim of this study is to compare, in a non-randomised retrospective study, the long-term patency after treatment of grafts’ stenosis by conventional PTA and PCB, also to check the influence of stent placement on graft’s survival. Methods: We reviewed 174 angioplastic procedures of AVGs, 112 PTA and 62 PCB. From 112 PTA, 83 were conventional PTA (PTA- group), 29 were performed by PTA plus stent implantation (PTA+ group). From 62 PCB, 32 were performed just by PCB (PCB- group) and 30 performed by PCB plus stent implantation (PCB+ group). Furthermore we investigated graft’s survival between different types of vascular grafts, PTFE, ePTFE, polycarbonate and bovine prosthesis , associated or not to stent placement. We performed each procedures under Doppler ultrasound guidance. The success rate was defined as a maximal = or < 30% residual stenosis of vessel lumen diameter, of the treated segment. Results: The mean graft’s survival time was 742±69 days and 1325±99 days with PTA and PCB respectively ( p=0,000, Log Rank and Breslow test). Comparing the PCB procedures with or without stent implantation we noticed a statistical evidence in long-term survival just for PCB+ group ( p=0,000, Log Rank and Breslow test). Therefore we analyzed the influence of stent implantation associated or not to PCB and we didn’t find a statistical evidence in grafts’ long-term survival ( p=0,15, Log Rank and Breslow test). We found no significant statistical differences on grafts’s survival between different types of grafts associated or not to stent implantation. Conclusions: Interpretation of these findings suggests that PCB improves graft’s survival over angioplasty alone. Stent placement influences graft’s long-term survival only when associated to PCB procedure, suggesting the idea that cutting balloon technique represents the key factor for the successful treatment of AVGs’ stenosis. The explanation might be that, the high-pressure balloon dilation of PTA causes a severe vessel wall injury and consequently neointimal hyperplasia while PCB provokes a controlled disruption of the vessel wall, decreasing the tendency to proliferative response and to elastic recoil. SP537 USE OF PLASTIC NEEDLES FOR EARLY ARTERIOVENOUS FISTULA CANNULATION Krzysztof Letachowicz1, Tomasz Gołe˛ biowski1, Mariusz Kusztal1, Waldemar Letachowicz1, Waclaw Weyde1 and Marian Klinger1 1 Wroclaw Medical University, Wroclaw, Poland Introduction and Aims: The best type of vascular access is a native arteriovenous fistula (AVF). An autogenous AVF requires maturation before it can be used: at least 4 iii | Abstracts SP538 ANTI-THROMBOTIC MEDICATION HAS NO EFFECT ON PRIMARY FAILURE RATE AND SURVIVAL OF SIMPLE ARTERIOVENOUS FISTULAE Alexander Murley1, Anika Wijewardane1, Sarah Powers1, Clive Allen1, Lee Hollingsworth1, Teun Wilmink1 and Jyoti Baharani1 1 Heart of England Foundation Trust, Birmingham, United Kingdom Introduction and Aims: Complications of dialysis access, including fistula thrombosis, are a common reason for patients with end stage renal failure to be admitted to hospital. Reducing the risk of fistula failure would improve patient's quality of life and improve dialysis outcomes. It has been suggested that use of antithrombotics (such as aspirin or warfarin), may reduce fistula primary failure rates and improve overall survival. The evidence so far is conflicting, some studies show benefit from antithrombotics, others no benefit and one study found increased complication rates (with no benefit) in patients taking antiplatelets. We were interested in how antithrombotic use affected outcomes in our local population. This study was performed with the aim of providing evidence (of benefit or harm) to clinicians considering whether to start patients on an antithrombotic before their fistula formation. Methods: Retrospective review of two prospective databases of access operations and dialysis sessions of 720 patients from 2004 to 2011. Follow up until 1 March 2013. Patients with previous fistula operations excluded. Primary failure (PF) defined as an arteriovenous fistula (AVF) used for fewer than 6 consecutive dialysis sessions. Needling complications defined as failure to reach 6 consecutive sessions from when the fistula first used. AVF survival defined as date AVF abandoned. Antithrombotic medication was ascertained from case records from the preoperative vascular and renal clinic letters. Antithrombotic medication was not stopped prior to AVF formation. Results: 720 patients were analysed: 47 excluded due to unknown outcomes and 2 non-standard fistulas removed. 372 (55%) patients were not on any antithrombotic medication, 203 (30%) were on aspirin, 24 (3.5%) on clopidogrel and 34 (5%) on warfarin. Antithrombotic medication had no significant effect on primary failure ( p = 0.98), needling complications ( p = 0.93) or AVF survival (log rank test, p = 0.98) nor was it a significant predictor of PF or AVF survival in a logistic regression model with proportional hazards adjusted for age, sex and type of AVF. Conclusions: Antithrombotic medication has no significant effect on primary failure rate, complications causing interruption of dialysis or survival of AV fistulas. Although not from a randomised control trial our results suggest that antithrombotic use is not associated with improved fistula outcomes. Fistula formation alone should not be an indication to start a patient on an antithrombotic medication. SP539 EFFECT OF AGE AND DIABETIC STATUS ON VASCULAR ACCESS (VA) FUNCTION IN PREVALENT HEMODIALYSIS (HD) PATIENTS Ramon Roca-Tey1, R Samon1,2,2, O Ibrik1,3, A Roda1,3, J C González-Oliva1,3, R Martínez-Cercós1,3 and J Viladoms1,3 1 Hospital de Mollet, Mollet del Vallès, Barcelona, Spain, 2Hospital de Mollet, Mollet del vallès, Spain, 3Hospital de Mollet, Mollet del Vallès, Spain Introduction and Aims: Some demographic and clinical settings of patients ( pts) undergoing chronic HD can affect the VA function which should be monitored by measuring the blood flow (Qa) rate (EBPG-2007). The aim of this study is to analyze the effect of age and diabetic status on VA function in prevalent HD pts under VA surveillance for stenosis by Qa measurements. Methods: We prospectively monitored the Qa of 145 VA (arteriovenous fistula AVF Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 weeks (Vascular Access Society guideline) or 6 weeks (European Best Practice Guideline 2007). Earlier needling may result in haematoma formation, miscannulation or even access loss. The mentioned above complications can lead to necessity of catheter placement or prolong its use. Aim of this study was to examine if application of plastic dialysis needles can reduce the risk of early puncture complication and minimize the period of catheter use. Methods: From May 2012 to January 2014 fluoroplastic dialysis catheters (SupercathTM CLS 502, 17 G 25 mm, Medikit) were used for early AVF cannulation in 22 patients. Early fistula use was defined as a first puncture within 30 days from access creation. All needling were performed by experienced nurse or nephrologist. The time of early AVF puncture, patients outcome and complications were recorded up to 4 weeks of follow-up. Results: Study group consisted of 22 patients (14 males and 8 females), mean age 58.9 ±22 years. AVF was located on forearm in 19 cases and on upper arm in 3 cases. Vascular access was cannulised early to shorten catheter usage in 17 patients (in case of complication or to prevent it) and avoid catheter placement in 5 patients. Period from fistula creation to first puncture was 2 to 29 days (mean time 10.2±7.1 days). In all cases first needling was successful. The strategy was effective in 20 patients (90.9%). In 2 patients complications occurred: access loss in 1 patient and necessity of temporary catheter placement in 1 patient. Conclusions: Use of plastic needle enables safe AVF cannulation within maturation process. It is an easy approach to minimize the risk of vessels perforation during dialysis. If applied reasonable it can minimize or even avoid catheter use. Abstracts Nephrology Dialysis Transplantation exists few comparative outcome studies. We compared TDC outcomes in a multiethnic Asian cohort with catheter malfunction treated by those 2 approaches. Methods: A restrospective analysis of 348 consecutive TDC inserted by nephrologists under mandatory sonographic and fluoroscopic guidance at a single centre over 3 years revealed 46 primary cases with poor flow (Qb<250mL/min) which failed thrombolysis, leaks or cuff extrusion treated by either exchange (group A, n=29) or denovo insertion (group B, n=17). Data on demographic factors, comorbids, laboratory and haemodialysis parameters were obtained from a prospectively collected TDC database. All cases in group A underwent exchange using a stiff hydrophilic guidewire with or without trans-tunnel peel-away sheath with mandatory prior pull-back cathetogram performed to identify fibrin sheaths which were then angioplastied. Primary and secondary catheter patency rates as per society of interventional radiology definition at 6 and 12 months was compared by Kaplan Meier analysis. Chi-square and t-test were used to compare acute bleeding, infection and malfunction free survival and re-do rates. A p value of <0.05 was taken as clinically significant. Results: The demographic, comorbid and haemodialysis characteristics were comparable in both groups and are outlined in table 1. Procedural success rate was 100 versus 94% in groups A and B respectively ( p=0.34). One left internal jugular de novo insertion resulted in a ruptured brachiocephalic vein which was stented. Bleeding rate within 48hours of insertion was 14 versus 17% ( p=0.73) in group A and B respectively. Median infection free catheter survival was 137 versus 47 days ( p=0.37). Confimed catheter-related infection was 0.8 versus 0.6 per 1000 catheter days ( p=0.77). Median malfunction free survival was significantly different (27 versus 68 days, p=.004). Fibrin sheath accounted for 33 versus 25% of all malfunctions ( p=0.35). Primary patency at 6 and 12 months in group A versus B was 41 versus 57% and 9 versus 11% respectively (Log rank =0.02, p=0.89). Secondary patency at 6 and 12 months was 67 versus 51% and 29 versus 17% (Log rank=1.61, p=0.28). Catheter re-dos were 3.55 versus 1.47 per 1000 catheter days ( p=0.26). Conclusions: Our findings suggest TDC exchange in our cohort is safe and does not lead to increased bleeding or infection rate nor affect overall catheter patency. It is however associated with a significantly lower malfunction-free catheter survival and nonsignificantly higher rate of re-insertions. However larger studies are required to further elucidate the benefits of tunnel exchanges. SP541 SP540 OUTCOMES OF PRIMARY TRANSJUGULAR TUNNELED CATHETER EXCHANGE COMPARED TO DE NOVO INSERTION IN AN MULTI-ETHNIC ASIAN COHORT Claude J Renaud1, Eng Kuang Lim1, Terina YY Seow1 and Hui Seong Teh1 1 Khoo Teck Puat Hospital, Singapore, Singapore Introduction and Aims: Tunneled dialysis catheters (TDC) are increasingly used for haemodialysis maintenance in endstage renal disease patients. However maintenance of uninterrupted catheter patency is dependent on successful treatment of malfunctions like thrombosis and fibrin sheath. Tunnel guidewire exchange offers an alternative to de novo placement and also preserves the venous real estate but there GENES THAT REGULATE ENDOTELIAL STRUCTURE/ FUNCTION:INFLUENCE ON VASCULAR ACCESS SURVIVAL? Jelena Tosic1, Aleksandar Jankovic1, Petar Djuric1, Vesna Radovic Maslarevic1, Jovan Popovic1 and Nada Dimkovic1,2 1 University Medical Centar Zvezdara, Belgrade, Serbia, Belgrade, Serbia, 2Medical Faculty, Belgrade University, Belgrade, Serbia Introduction and Aims: Functional, long-lasting vascular access is essential for maintaining effective long-term haemodialysis (HD). Given the importance that AVFs (arteriovenous fistula) have in maintenance of HD treatment, there is a constant need to find out the cause of it’s failure/survival. Genetic susceptibility may be of importance including angiotensin converting enzyme (ACE), matrix metalloproteinase 3 (MMP 3) and endothelial nitric oxide synthase (eNOS) polymorphism. The aim of this study was to analyse influence of ACE, MMP 3 and eNOS gene polymorphism on AVF survival. Methods: This retrospectrive study included 176 patients treated by chronic HD for more than 6 months. They were divided into two groups: group 1-patients without vascular access failure (No=94); group 2-patients with at least one vasular access failure (No=82). Genetic analysis was performed by using polymerase chain reaction restriction fragment lenght polymorphism method (PCR-RFLP). Results: It was shown that patients with I allele of ACE gene experienced 2,2 folds higher risk for developing thrombosis of AV fistula. It has also been proved that 6A alelle of MMP3 gene have a protective effect regarding thrombosis of AVF with twice lower risk for its failure. Although without statistical significance, T/T homozygots for eNOS gene have shown 1,3 folds higher risk for developing AV fistula thrombosis, while G/T heteroyzgots had 1,5 folds higher risk for this unwanted outcome. Conclusions: Apart from different risk factor, genetic milieu may influence AVF outcome. This finding may be of significance when patient is given proper information about modality selection. Still, we need longer follow-up in order to make a definitive conclusion about the influence of these gene polymorphisms on AVF survival in haemodialysis patients and its importance in every-day clinical practice. SP542 SURVIVAL OF TOTAL VASCULAR ACCESSES AND OF PREOPERATIVE ULTRASOUND MAPPED VASCULAR ACCESSES IN HEMODIALYSIS PATIENTS Alexandra Kazantzi1 and Konstantina Trigka1 Kyanus Stayros, Patra, Greece 1 SP540 Volume 29 | Supplement 3 | May 2014 Introduction and Aims: Vascular access is the thread of life for hemodialysis (HD) patients. Preoperative vascular mapping is proposed for improving access outcome. We compared survival of arteriovenous- fistulas (AVFs), grafts (AVGs) and catheters as well as possible correlations with advanced age, smoking, diabetes. Survival between mapped versus non mapped AVFs and AVGs was also dealt. Methods: We evaluated retrospectively 92 HD patients from a HD center in Greece with 118 vascular accesses creation during 01.2008-09.2013. Each patient presented doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 84.1% or graft AVG 15.9%) during HD in 131 ESRD (age 62.6 ± 13.5 yr) pts over 5 year period. Of them, we analyze the function of 30 VA (AVF 73.3%) in 28 pts (21.4%) aged ≥75 years (elderly pts, EP) and 26 VA (AVF 84.6%) in 25 pts (19.1%) with diabetic nephropathy (diabetic pts, DP). The Qa was measured, at least every 4 months, within the first hour of the HD session by the Delta-H method. All VA with baseline Qa lower to 700 ml/min or Qa decreased more to 20% from baseline over time met the positive evaluation criteria and were referred for angiography plus subsequent elective intervention if VA stenosis ≥50%. Results: We found an inverse correlation between patient's age and baseline or overall Qa (r= - 0.37 and - 0.38, respectively; p<0.001 for both correlations). The baseline (812.6 ± 290.8 ml/min) and overall (867.9 ± 292.8 ml/min) mean Qa recorded from 30 VA in EP were lower when comparing to the remaining VA (n = 115; 1171.3 ± 436.9 and 1244.6 ± 481.0 ml/min, respectively) (for both comparisons, p < 0.001). Of these 30 VA in EP, we found 11 cases (36.7%) of significant stenosis identified from a baseline Qa < 700 ml/min (n = 9, 81.8%) and a decrease of Qa over time (n = 2). The baseline mean Qa obtained from these 9 VA in EP with stenosis was lower (504.4 ± 83.8 ml/min) compared with the baseline mean Qa recorded from the remaining 21 VA without stenosis in EP (944.7 ± 242.4 ml/min, p < 0.001) that, in turn, was lower compared with the baseline mean Qa obtained from 101 VA without stenosis in pts aged < 75 years (1264.7 ± 388.9 ml/min, p < 0.001).On the other hand, the baseline (888.5 ± 415.4 ml/min) and overall (929.7 ± 411.3 ml/min) mean Qa recorded from 26 VA in DP were lower when comparing to the remaining VA (n = 119, 1140.7 ± 430.6 and 1220.1 ± 472.4 ml/min, respectively) ( p=0.008 and 0.004, respectively). Of these 26 VA in DP, we found 13 cases (50%) of significant stenosis identified from a baseline Qa < 700 ml/min (n = 10, 77%) and a decrease of Qa over time (n = 3). The baseline mean Qa obtained from these 10 VA in DP with stenosis was lower (524.5 ± 102.6 ml/min) compared with the baseline mean Qa recorded from the remaining 16 VA without stenosis in DP (1114.2 ± 356.6 ml/min, p < 0.001) that, in turn, was not different when compared with the baseline mean Qa obtained from 106 VA without stenosis in not-diabetic pts (1223.7 ± 390.4 ml/min, p = 0.27). Conclusions: 1) The VA function is related to patient’s age and diabetic status. 2) The functional VA impairment linked to age seems to be not stenosis-dependent and could be secondary to the changes of the vessel wall related to the aging process. 3) The functional VA changes recorded in diabetics seem to be secondary to stenosis development. Abstracts Nephrology Dialysis Transplantation SP543 PRE-EMPTIVE REPLACEMENT OF PERMANENT CENTRAL VENOUS CATHETERS FOR HEMODIALYSIS: PRELIMINARY STUDY Francesco Buono1, Simona Laurino1, Giampiero Toriello1, Rosanna Di Luccio1 and Antonio Galise1 1 Hospital Luigi Curto, Polla -Salerno, Polla-Salerno, Italy Introduction and Aims: Native Arthero-venous fistula (AVF) is well recognized as the gold standard of hemodialysis vascular accesses. Nevertheless, in contrast with KDOQI guidelines, the use of central venous catheter (CVC) as permanent vascular access is widespread, because of the increasing number of elderly patients, who have several comorbidities such as obesity and poor vascular assets.CVC have the burden of a high incidence of related complications, like infection, thrombosis, malfunctioning, failure, thus increasing mortality and morbidity of our patients and leading to a heavy economic impact on our national health system.The average duration of a tunneled CVC is less than 12 months [1, 2].We hypothesized that, in CVC dependent patients, periodic (every 12-13 months) pre-emptively substitution (before the occurrence of major complications) of CVC could reduce the rate of CVC related complications with a better preservation of vascular tree Methods: We enrolled 10 patients divided in two groups of 5 patients.In group 1 patients we replaced CVC every 12 months, independently from the presence of complications, whereas in group 2 patients we had a “wait and see” approach, considering the intervention only in case of major complications.Total follow-up was 5 years. Results: In group 1 patients we examined the tip of removed CVC and found staphilococcus aureus infection in 2 and minor infections in 3 (Table 1).Group 1 patients presented with low PCR levels and good Kt/V.Deaths were 0 in group 1 and 3 in group 2.Short and long term complications rate was higher in group 2 compared to group 1 (table 2) Conclusions: The disadvantage of a periodical surgical replacement of CVC is exceeded by the benefit of a better life quality, and could permit to spare more invasive and potentially dangerous interventions.It remains to be shown if pre-emptive replacement of CVC can improve survival in hemodialysis patients who failed other vascular accesses (AVF or graft) and in which CVC is the only one possibility. SP543 Table 2: CVC related complications in group 1 and group 2. Complication Sepsis Exit site infection Thrombosis Malfunctioning Breaking SP544 Group 1 0 2 0 0 0 Group 2 2 0 3 3 1 ARTERIAL MICRO-CALCIFICATION IS ASSOCIATED WITH CORONARY ARTERY CALCIUM SCORE IN HEMODIALYSIS PATIENTS Young Ok Kim1, Sun Ae Yoon1, Young Soo Kim1, Su Jin Choi1, Ji Won Min1 and Myeong A Cheong2 1 Uijeongbu St. Mary’s Hospital, Uijeongbu-city, Republic of Korea, 2Korea Cancer Center Hospital, Seoul, Republic of Korea Introduction and Aims: We have reported that arterial micro-calcification (AMC) of vascular access has a negative impact on access patency and cardiovascular mortality in hemodialysis (HD) patients. Reasons behind increased cardiovascular mortality in AMC are not fully understood, but it is believed that aortic stiffness is a major contributing factor. Whereas, coronary artery calcification (CAC) is quite common in HD patients and it is known as predictor of future cardiovascular events and all cause mortality in HD patients. The aim of this study was to explore the relationship between AMC and CAC in HD patients. Methods: One hundred HD patients who received vascular access operation were included in this study. The AMC was diagnosed by pathologic examination of arterial specimen by von Kossa stain, which was acquired during the operation. All patients underwent a multi-detector computed tomography (MDCT) imaging procedure and coronary artery calcium score (CACS) was calculated. Patients were classified into two groups, according to the CACS, as low (<100), in 40 patients, and high (≥100), in 60 patients. We compared CACS between the patients with and without AMC. Results: Mean age was 65.1 ± 12.7 years and the male gender was 63 (63.0%). The incidence of AMC was 60.0% (n=60). The mean CACS was 486.8 ± 857.6 (0-5674.1), and the median value was 161.2. Patients with the positive AMC group showed a significantly higher prevalence of diabetes (85.7% vs 45.5%, p=0.000). Positive AMC group showed high incidence of high CACS compared to negative AMC group (76.8% vs 38.6%, p=0.000). By binary logistic regression, high CACS was independently associated with positive AMC (OR 7.566, 95% CI 1.771-32.322, p=0.006). Conclusions: The present study suggests that AMC is closely associated with CACS in HD patients. SP545 RELATIONSHIPS BETWEEN INTRADIALYTIC BODY WEIGHT REDUCTION AND OUTCOME OF VASCULAR ACCESS: USING DATA FROM THE JAPAN DIALYSIS OUTCOMES AND PRACTICE PATTERNS STUDY (J-DOPPS) Manabu Asano1, Kenichi Oguchi1, Akira Saito2, Yoshihiro Onishi3, Yosuke Yamamoto4, Shunichi Fukuhara5,6, Takashi Akiba7, Tadao Akizawa8 and Kiyoshi Kurokawa9 1 Ikegami General Hospital, Tokyo, Japan, 2Shonantobu Genaral Hospital, Kanagawa, Japan, 3Institute for Health Outcomes & Process Evaluation Research (I-Hope International), Kyoto, Japan, 4Kyoto University Hospital, Kyoto, Japan, 5 Kyoto University Graduate School of Medicine and Public Health, Kyoto, Japan, 6 Fukushima Medical University, Fukushima, Japan, 7Tokyo Women's Medical University, Tokyo, Japan, 8Showa University School of Medicine, Tokyo, Japan, 9 National Graduate Institute for Policy Studies, Tokyo, Japan Introduction and Aims: Large-volume ultrafiltration might be an important risk factor for vascular access (VA) trouble in hemodialysis patients. However, the relationship between intradialytic body weight reduction and VA patency remains unclear. The aim of the study was to determine whether large-volume ultrafiltration was associated with VA failure utilizing the results obtained from the phase 4 J-DOPPS. Methods: We analyzed data from the phase 4 J-DOPPS. The analyses was limited this time to 1957 patients for whom it was possible to evaluate VA patency and body weight change during dialysis. According to the quartiles of intradialytic fluid removal per body weight, the subjects were divided into 4 groups as follows Q1: -8.3 to 2.8%, Q2: SP543 Table 1: bacterial colonization of removed CVC during follow-up in group 1 patients Patient I year II year III year IV year V year 1 2 3 4 5 Staphilococcus Epidermidis sterile Enterococcus Staphilococcus Epidermidis Sterile Sterile Enterococcus Sterile Staphilococcus Epidermidis Staphilococcus aeureus Staphilococcus aureus Streptococcus viridans Staphilococcus Epidermidis Sterile Streptococcusviridans Staphilococcus Epidermidis Staphilococcus Epidermidis Sterile Staphilococcus Epidermidis Stafilococcusaureus Sterile Sterile Sterile Sterile Sterile iii | Abstracts Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 with multiple accesses. Survival rates were calculated as the difference between access placement and removal or substitution, using Kaplan-Meier for different accesses and according age , smoking and diabetes status.Percentage of preoperative mapped (Doppler ultrasound) AVFs and AVGs and eventual percentage of functionality of accesses was calculated. Results: 92 patients with mean age 72.2±12.2 were studied, 62.5% were males and 31.8% diabetics, Mean number of accesses per patient was 1.2. (61.1% AVF, 14.4% AVG and 31.3% CLs). 59.1% of the AVFs were proximal and 79.4% situated on the left hand.Total mean survival rate was 28±29 mo for AVFs, 30±25mo for AVGs and 15±14mo for CLs. Occluding rate was 44.8% for AVFs, 52.9% AVGs and 16.2% for CLs. Survival rates for AVFs was 22±23 mo for 70 years old. Survival rates for AVGs was 33±32 mo for 70 years old. As for CL, survival patency was 19±20 mo for 70 years old. We report slightly better survival patency of non smokers (AVF survival 29±30 vs. 25±24, CL 15±14 vs. 11±17, AVG 41±36 vs. 25±16 for non smokers vs. smokers). Survival curves for AVFs, were better in diabetics (38±12 vs. 33±11 mo), while catheters survival-patency curves were better for non diabetics (16±6 vs. 14±2mo). Concerning access mapping prior to access creation, we report 27.1% mapped vs. 72.8% of non- mapped. Total median survival was 21±19 and 31±30 mo respectively.27.2% AVFs and 52.9% AVGs were mapped. Median survival of mapped AVFs was 23±20 mo vs. 31±32 of non mapped. Median survival of mapped AVGs was 23±20 mo vs. 32±27 of non mapped.Both venous and arterial ultrasound criteria for AVF creation were met in 86.3% proximal and in 45.4% distal forearm. In one case an anatomical variation was observed in forearm venous vasculature. Conclusions: AVF was the first vascular access choice for the majority of patients. Similar total survival rates and functionality loss for AVFs and AVGs, but lesser for CLs was reported. Better survival patency curves were demonstrated in older HD patients for AVFs and CLs compared to AVGs. Higher survival rates were observed for AVFs and CLs regarding smoking. Diabetics displayed higher AVF survival rates.We report a small percentage of preoperative mapping prior to access creation. Survival of mapped limbs was not superior to non- mapped. Nevertheless, we underline the importance of radiological mapping prior to access creation, especially in detecting anatomical vasculature variations in order to help clinical decision making. Abstracts Nephrology Dialysis Transplantation SP546 sensor BTM® (Blood Temperature Monitor), Fresenius Medical Care, incorporated in the machines.We used SPSS, 20.0. We compared both Qa measurements and evaluated their correlation using the paired t-test and Pearson coefficient. Kruskal Wallis and Mann-Whitney Test were made to find if Qa values varied significantly with different factors related to the VA. Results: We evaluated 40 patients in hemodialysis with a mean age of 64,5 ± 13,7; average time on HD of 51,4 ± 47,3 and average time of VA of 47,6 ± 42,1.Mean DU-Qa was 1032,5 ± 468,7 mL/min, and mean TD-Qa was 1012,0 ± 492,9 mL/min. Paired T test between TD and DU methods revealeda mean difference of only 20,55 ml/min, with a p-value of 0,624 (> 0,05).Correlation coeficiente of Pearson was 0,851, p-value ,000 (< 0,05) (graphic 1).DU-Qa varied significantly with VA type ( p0,021), motive of DU request ( p 0,006), artery characteristics/stenosis ( p 0,048), as well as, the presence ( p 0,038), location ( p 0,031) and number of stenosis ( p 0,034). On the other hand, TD-Qa only varied significantly with the presence ( p 0,039) and number os stenosis ( p 0,012). Anastomosis and vein characteristics, as well as the hemodynamic meaning of the stenosis didńt affect any of the Qas (TD and DU). Conclusions: TD represents a good indirect method of DU-Qa measurement. However they vary differently with VA-related factors. DU provides a more accurate evaluation of VA. Through Qa measurement, it identifies earlier a subset of patients at increased risk of future access thrombosis and allow for intervention prior to the clotting event. ULTRASOUND DOPPLER: A POWERFULL TOOL FOR HEMODIALYSIS VASCULAR ACCESS Maria Guedes Marques1, José Ibeas2, Pedro Maia1 and Pedro Ponce3 1 Hemodialysis Unit, Nephrocare Coimbra, Coimbra, Portugal, 2Hospital de Sabadell, Parc Tauli, Sabadell, Barcelona, Spain, 3Hemodialysis Unit, Nephrocare Coimbra, Lisbon, Portugal Introduction and Aims: Complications of vascular access (VA) for hemodialysis are major causes of morbidity and mortality in end stage renal disease patients. The most common complication of hemodialysis access is thrombosis due to flow-limiting stenosis, which eventually leads to access failure. Under the paradigm ‘‘prevention is better than cure’’ to achieve and maintain a mature VA, the NKF-K/DOQI recommends that accesses should be monitored regularly for the detection of stenosis, and if detected, it should be treated with elective angioplasty or surgery prior to thrombosis.Surveillance methods are access flow (Qa), venous pressure, recirculation, or other parameters. Qa can be measured using a direct method as Doppler ultrasound (DU) and indirect as ultrasound dilution, which are nowadays the gold standardtechniques. Other indirect measurement techniques include transcutaneous flow rate measurement, glucose infusion, differential conductivity (TD), and ionic dialysance.Although KDOQI Guidelines recommend DU as the preferred method for Qa surveillance (evidence A), this practice is operator-dependent, require expensive equipments and is prone to errors.We evaluated the efficiency of Qa measurement with the DU method in comparison to the TD, anf if other factors related to the VA could affect significantly each one of them. Methods: Transversal study in 40 patients in hemodialysis.DU-Qa was evaluated in the humeral artery. In the same week, TD-Qa was measured with the blood temperature SP547 EXCHANGE FROM NON-TUNNELED TO TUNNELED HEMODIALYSIS CATHETER WITH OVER THE GUIDEWIRE CAN BE PERFORMED WITHOUT INCREASING COMPLICATION RISK Kyung Yoon Chang1, Hoon Suk Park1, Hyung Wook Kim1, Bum Soon Choi2, Cheol Whee Park2, Chul Woo Yang2 and Dong Chan Jin1 1 The Catholic University of Korea, St. Vincent’s Hospital, Suwon, Republic of Korea, 2The Catholic University of Korea, Seoul, Republic of Korea Introduction and Aims: Exchange from non-tunneled hemodialysis (HD) catheter to tunneled HD catheter over the guidewire using previous venotomy has advantage that it does not require new venipuncture so that it can prevent additional injury to vessel wall. Several previous studies demonstrated its safeties, but concerns that it can be associated with infection and bleeding prevent it from being chosen rather than de novo placement. Therefore, we investigated its safeties in our center. Methods: Twenty five patients who started initially HD with non-tunneled catheter and then received catheter exchange procedure into tunneled catheter and one hundred and ten patients who initially received de novo placement of tunneled HD catheter within the same period were respectively assigned to exchange and de novo placement groups. Catheter survival, immediate and long term complication rates were compared. Results: Catheter exchange into tunneled catheter was performed at 10±3 days after initial insertion of non-tunneled catheter. Immediate complication rates including exit site bleeding, bruise and hematoma were comparable (26.3% in exchange group vs. 23.7% in de novo placement group, p = 0.8). Long term complication rates including catheter dysfunction and catheter related infection (5.3% in exchange group vs. 8.8% in de novo placement group, p = 0.61) and catheter survivals ( p = 0.7) were also comparable between 2 groups. Conclusions: Exchanging procedure over the guidewire from non-tunneled to tunneled catheter was comparable with de novo placement of tunneled catheter in complication rates and catheter survival, in spite of merit in avoiding unnecessary additional vessel wall injury. Therefore it should be firstly considered in the cases where replacement non-tunneled catheter with tunneled one is required. SP548 CALCIFICATION OF CARDIAC VALVES AND ARTERIO VENOUS FISTULA THROMBOSIS,WHAT STANDS BEHIND? Erjola Likaj1,1, Saimir Seferi1, Gentian Caco1, Elizama Petrela1, Myftar Barbullushi1, Alma Idrizi1 and Nestor Thereska1 1 UHC Mother Theresa, Tirana, Albania SP546 Volume 29 | Supplement 3 | May 2014 Introduction and Aims: ESRD and then hemodialysis bring themselves a wide variety of difficult to manage and to solve problems with calcium and phosphorus metabolism and cardiac valve calcifications. It"s always thought to exist a strong connection betweeen them. Controlling the mineral bone disease in hemodialysis patients is very difficcult and sometimes hopeless. It is maybe labyrinthyc to think about a link between cardiac valve calcifications, disregulation of calcium-phosphorus metabolism and AVF thrombosis. We decided to solve this labyrinth ongoing this study.The objective of this study was to evaluate the impact of calcium phosphorus abnormalities and cardiac valve calcification presence on arteriovenous fistula (AVF) thrombosis in patients on regular hemodialysis (HD). Methods: There were 103 patients enrolled in the study (62=60.2% males, 41=39.8% females, mean age 50.27± 12.18 years) on chronic hemodialytic treatment, HD (mean duration of HD 54,64 ± 43,27 months) that were screened for calcification of the cardiac valves. Primary renal disease were as follows: chronic glomerunephritis 29.5%, chronic pyelonephritis 29%, nephroangiosclerosis 14,6%, ADPKD 14%, Diabetic nephropathy 9,7% and the rest ESRD of unknoun origin. Baseline echocardiography doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 2.8 to 3.9%, Q3: 3.9 to 4.9% and Q4: 4.9 to 11.7%. The hazard ratios of VA failure were compared across these groups using Cox regression models. The models were adjusted for the known risk factors (e.g. age, gender, BMI, diabetes, hemoglobin, phosphorus, Kt/V, ESA use, antiplatelets use). Primary VA patency was defined as the time until the first VA intervention, and secondary patency was defined as the time until the creation of a new VA. Results: The incidence rates of primary and secondary VA events were 8.1 and 2.3%, 4.9 and 1.4%, 7.2 and 2.0%, 6.6 and 1.9% for Q1, 2, 3, 4, respectively. The adjusted hazard ratios for primary VA patency versus Q2 group were 1.48 (95% confidence interval [CI], 1.02 to 2.15; p=0.04) in Q1, 1.57 (CI, 1.09 to 2.24; p=0.01) in Q3 and 1.49 (CI, 1.03 to 2.15; p=0.04) in Q4, respectively.The hazard ratios for secondary VA patency versus Q2 group were 1.45 (CI, 0.74 to 2.85; p=0.34) in Q1, 1.44 (CI, 0.75 to 2.76; p=0.33) in Q3 and 1.46 (CI, 0.74 to 2.86; p=0.34) in Q4, respectively. Conclusions: The present study showed that intradialytic ultrafiltration volume was significantly associated with primary VA failure in hemodialysis patients. Therefore, we would like to recommend less than 4% of body weight gain between dialyses with respect to VA patency. Abstracts Nephrology Dialysis Transplantation SP549 EFFICACY AND SAFETY OF A NEW TECHNIQUE OF CONVERSION OF TEMPORARY TO TUNNELED CENTRAL VENOUS CATHETERS Carlo Lomonte1, Francesco Casucci1, Pasquale Libutti1, Piero Lisi1 and Carlo Basile1 1 "F.Miulli" General Hospital, Acquaviva delle Fonti, Italy Introduction and Aims: The conversion technique of temporary central venous catheters (CVC) to tunneled catheters using the same venous insertion site has been described in the literature (Falk, Semin Dial 2005; Van Ha, Cardiovasc Intervent Radiol 2007). The latter required a peel-away technique, which may increase the risk of immediate complications, especially in the elderly patients. We propose a new conversion technique using a guidewire, without the use of the peel-away sheath. The efficacy and safety of this technique was evaluated. Methods: All incident patients starting hemodialysis with a temporary CVC from January 2012 to December 2013 were included in the study. As control group, a historical one of incident patients who received de novo placement of tunneled CVC from January 2010 to December 2011, was evaluated. All the CVC were inserted with a Doppler US image guidance. The temporary polyurethane CVC (Vascath Flexxicon ®, 11.0 Fr, Bard, USA) and tunneled silicon CVC (Mahurkar ™, Fr 13.5 Fr and PermCath ™,14.5 Fr, Covidien USA) of appropriate length were used. In the conversion technique, a guidewire was advanced through the existing CVC; then a subcutaneous tunnel was created from the upper chest, or outer thigh surface, to the venotomy site. After removal of the temporary CVC, the tunneled one was placed over the guidewire. Chest or abdominal X-rays were always performed to check for the correct tip placement. The outcome measures were: technical success (correct tip position); catheter performance (Qb < 200 ml/min); immediate complications (IC): number of events as bleeding, pneumothorax, and air embolism. Results: Thirty-five CVC were placed in the right jugular vein (RJV); 15 in the left jugular vein (LJV) and 5 in the femoral vein (FV). The comparison between the two groups is reported in the table 1. The temporary CVC had been in place 10±6 days, neither skin infection or CVC-related bacteremia occurred in this period. In the group 1, only one CVC had a kinking at its top. In the group 2, 5 CVC (3 inserted in LJV, 1 in RJV, 1 in FV) were dislodged; 3 CVC had a kinking at their top. Qb < 200 ml/min was present in 8 CVC: one of the group 1 and 7 of the group 2. No IC resulted with the conversion technique, whereas, two air embolisms, one pneumotorax, and three bleeding episodes occurred in the controls. Conclusions: The conversion of temporary CVC to tunneled CVC without a peel-away sheath is an effective and safe procedure. The conversion technique may be advised as elective especially in the elderly patients, when the LJV and FV sites are used. SP549 Table 1. Comparison between the two groups Group 1 (conversion) n. (m/f) 28 (15/13) Age, ys 72 ± 7.3 RJV 18 LJV 7 FV 3 Technical success 27/28 (96%) Qb<200ml/min 1/28 (3.5%) IC 0/28 (0%) iii | Abstracts Group 2(historical controls) 27 (13/14) 71± 6.8 17 8 2 19/27 (70%) 7/27 (26%) 6/27 (23%) *Fisher’s exact test NS NS NS NS NS *0.011 *0.024 *0.010 SP550 CATHETER RELATED INFECTION IN HEMODIALYSIS : SINGLE CENTRE EXPERIENCE Paolo Ancarani1, G. Valsuani, L. Cavallo, D. Parodi and Carolina Lorusso2 1 Civil Hospital, Sestri Levante (Genoa), Italy, 2Infectious Disease Service, Chiavari (GE), Italy Introduction and Aims: Optimal vascular access (VA) is vital for hemodialysis (HD) patients. The best VA remains arterio venous fistula (AVF) but its creation is not always feasible and often a central venous catheter (CVC) remains as permanent access particularly in ancient patients or in patients with cardiovascular comorbilities. The aim of our retrospective study is to evaluate the infection rate of CVC, bacteriologic analysis and correlation with CVC characteristic ( site, cuffed or not and time of CVC in place). Methods: During 5 years, from January 2009 to December 2013, 322 CVC were placed in 170 patients ( mean aged 72+/-16 years). 255 CVC were temporary catheter (tCVC) and 67 CVC were cuffed catheter (cCVC). CVC were placed by nephrologist in internal giugular vein and femoral vein. Each CVC was followed until it was removed or until the end of the study. CVC were followed up for 26590 days. 194 of them were placed in jugular vein ( 60%) , 128 (40%) in femoral vein . The diagnosis of infection was based on clinical evidence and positive blood culture with no sign of other infection site. We also evaluated the exit site/tunnel infection (ESI/TI) rate. Even rates were calculated per 1000 catheter days. Results: Mean tCVC duration was 28 days and 228 days for cCVC. Catheter related bloodstream infection (CRBI) were developed in 37 cases, ESI/TI were developed in 29 cases. Incidence for CRBI were 1,4 /1000 days catheter and ESI/TI were 1,1 /1000 days catheter. Rates of CRBI in tCVC were 2,8 episodes /1000 days catheter and 0,7 episodes /1000 days catheter in cCVC. ESI/TI rates were 0,7 episode/1000 days catheter in tCVC and 1,2 episodes/1000 days catheter in cCVC. In ESI/TI the most common organism isolated was Staphilococcus epidermidis (45%), in CRBI the most common organism isolated were MRSA (29%) and MSSA (21%). The majority of CVC infections (80%) were cleared with systemic antibiotics and lock therapy. Conclusions: Our data suggest an high survival rate and a low rates of CRBI in cCVC . Infections were successfully treated with conservative therapy in most cases. These data justify cCVC use in hemodialysis, especially in ancient patients with poor vascular assets. A nursing care standard protocol can prevent CVC related infection and contribute to an early diagnosis. SP551 PREDICTORS OF ACUTE BLEEDING AFTER PRIMARY TUNNELED CATHETER INSERTION Claude Renaud1, Boon C Lai1, Samuel Tho2 and Ly Yeoh1 1 Khoo Teck Puat Hospital, Singapore, Singapore, 2Monash University Faculty of Medicine, Nursing and Health Sciences, Monash, Australia Introduction and Aims: Tunneled dialysis catheters (TDC) are widely used for haemodialysis initiation and maintenance, against current practice guideline recommendations which advocate a fistula first approach. Arguments against TDC are more for their long-term than acute complications (ie infections, thrombosis/fibrin sheath, central vein stenosis versus misplacement and vascular/visceral injury) given the low incidence of the latter with image-guided insertion nowadays. However catheter bleeding (CB) from exit and venotomy sites remains a major problem often resulting in prolonged hospital stay and additional interventions. Catheter bleeding has been attributed to concentrated heparin lock and failure to place exit-site purse-string sutures but it is not clear if it is a risk factor for catheter related infection (CRI) and malfunction. We therefore studied predictors of CB in a multi-ethnic Asian cohort and its association with these complications. Methods: This was a retrospective analysis of 239 consecutive primary internal jugular TDC inserted in 212 patients by nephrologists at a single center over 3 years. All TDCs were inserted under sonographic and fluoroscopic guidance. Guide-wire exchanges were excluded. Demographic, co-morbid, laboratory parameters, haemodialysis and TDC data were obtained from a prospectively collected database. Cases were divided into 2 groups: A (CB within 48 hours after insertion, n=32) versus B (no bleeding, n=207).Bleeding was defined as a need to change blood-soaked dressing > 2 in 48 hours or to apply local adrenaline injection or systemic protamine sulphate and graded as per American Society of Diagnostic Interventional Nephrology classification. Categorical and continuous variables in each group were compared by Chi-square and t-test and presented as frequency/percentage and mean±standard deviation respectively. Outcomes evaluated were CRI and malfunction rate defined as confirmed bacteremic infection with no other identifiable source and a failure to acheive a blood flow >250mL/min on > 3 occasions respectively. A p-value of <0.05 was taken as significant. Results: Demographic, co-morbid, laboratory parameters, antiplatelet, purse string utilization, heparin lock dose, haemodialysis and TDC characteristics in groups A and B were comparable and are outlined in table 1. CRI rate at 48hours and 30 days in A versus B were 0 versus 0.5% (p=0.87)and 3.1 versus 2.4% (p=0.58) respectively. Rate of malfunction at 48hours and 30 days were: 3 versus 1.4% (p=0.44) and 6 versus 3.4% (p=0.35) respectively. All bleeding episodes were grade 1 except for 2 cases of left brachiocephalic vein rupture (grade 3) with 1 requiring stenting. Avoidance of antiplatelets had a nonsignificant odds risk of 0.53 (CI 0.27-1.05) of reducing CB. There was no significant association between heparin lock concentration and use of exit-site suturing and CB risk. Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 was performed to screen for calcification of the cardiac valves. Echocardiograms were graded as 0-1 for absence or presence of calcification of the mitral and aortic valve. The patients were stratified according to the presence of calcifications or not in two groups: group I, without valvular calcification; group II with calcified valve (either mitral or aortic or both valves). Prior history of AVF thrombosis was obtained through a questionnaire. Results: 44 patients (42.7%) had previous episodes of AVF thrombosis. A significantly higher percentages of previous history of AVF thrombosis were observed in the group with calcified valves in comparison with group without cardiac valve calcification. Binary logistic regression analyses that the identified cardiac valve calcification presence (one,both valves),serum calcemia and serum phosphoremia are factors significantly associated with the arterio venous fistula thrombosis.Patients with cardiac valves calcifications has a 28% higher risk to have AVF thrombosis compared to those without cardiac valves calcifications (OD:1.28, CI95%: 1.17-3.38]For every 1mg/dl increase in phosphorus levels in blood the risk to have AVF thrombosis increases with 1% [OD:1.01, CI95%: 1.003-1.33];For every 1 mg/ dl fall in calcium levels in blood the risk to have AVF thrombosis increases with 5.5% [OD:1.06, CI95%: 1.014-1.62] Conclusions: The episodes of AVF thrombosis in HD patients are more frequent in patients with detected cardiac valve calcification. The presence on echocargiography of cardiac valve calcification and mineral bone disease with calcium and phosphorus disregulations is associated with higher occurrence of AVF thrombosis in these patients Abstracts Nephrology Dialysis Transplantation SP553 PREDICTION OF EARLY FAILURE OF NATIVE ARTERIOVENOUS FISTULAS: OUTCOME A SINGLE CENTER Andrey Yankovoy1, Sinutin Alexandr1, Alexandr Smoliacov1 and Vadim Stepanov1 Moscow Regional Research Institut, Moscow, Russian Federation 1 Conclusions: This study did not identify any significant risk factor for early CB. It refutes previously established associations of CB with high heparin concentrations and purse string suturing. Early bleeding does not predispose to early CRI or catheter malfunction. However larger controlled studies are required to further allay these controversies. SP552 SP554 HEMODIALYSIS VASCULAR ACCESS, HOW TO IMPROVE IT? Maria Guedes Marques1, Carlos Botelho2, Pedro Maia1 and Pedro Ponce3 1 Hemodialysis Unit, Nephrocare Coimbra, Coimbra, Portugal, 2Hemodialysis Unit, Nephrocare Viseu, Viseu, Portugal, 3Hemodialysis Unit, Nephrocare Lisboa, Lisboa, Portugal Introduction and Aims: Vascular access (VA) function and patency are essential for optimal management of hemodialysis (HD) patients. Loss of patency of the VA limits HD delivery and may result in underdialysis that leads to increased morbidity and mortality. The stimuli responsible for intimal hyperplastic response in the venous outflow tract are multifactorial and include hemodynamic factos, as well as atherosclerotic vascular disease and vascular inflammation. Other factors include diabetes mellitus, anticardiolipin antibodies, patient age, previous use of a dialysis catheter, hypoalbuminemia, and high serum levels of lipoprotein A and fibronectin. Vascular calcifications are highly prevalent in dialysis patients and are associated with arterial stiffness and mortality. Teresa Adragão et al, developed a simple vascular calcification score (SVCS) predictor of cardiovascular mortality and higher vascular calcification and arterial stiffness.The NKF-K/DOQ recommended several diagnostic procedures for VA surveillance, including duplex ultrasound, blood flow (Qa), intra-access static pressure, access recirculation and others.Decreasing Qa add predictive power for the detection of access stenosis, thrombosis and loss of VA patency.We try to find if SCVS and other clinical and analitical parameters affect Qa values as a way to improve VA surveillance. Methods: Transversal study in 40 patients in regular hemodialysis. Qa value was obtained with TD and DU method in the same week.Demographic variables such as race, age, gender, diabetes and arterial hypertension status, time on dialysis, VA type and time, first VA or not, previous interventions (endovasculars or surgicals), SCVS, serum parathyroid hormone, calcium, phosphate, bicarbonate and magnesium levels, mean static venous and arterial pressure, online clearance monitor (OCM), recirculation were recorded. We also recorded alterations observed with DU like stenotic lesions, their location, number and hemodynamic meaning.We used SPSS 20.0. Pearson coefficient was made to find correlation between both Qa measurement methods. Kruskal Wallis and Mann-Whitney Test were made to compare both Qa measures in multiple groups. Results: Pearson coeficiente betwenn DU-Qa and TD-Qa was 0,851, p-value ,000 (< 0,05). DU-Qa varied significantly with age ( p 0,012), VA type (0,021), SCVS (all categories) ( p 0,030), mean intra-access arterial pressure ( p 0,015) and time on dialysis ( p 0,002). TD-Qa only varied significantly with diabetes status ( p 0,027), age ( p 0,017), first or not VA ( p 0,036), SCVS (> or < 4) ( p 0,007), mean intra-access arterial pressure ( p 0,028) and time on dialysis ( p 0,001) On the other hand, gender, hypertensive status and analitical parameters related with metabolism bone disease and vascular calcification didńt change Q values. Conclusions: TD represents a good indirect method of DU-Qa measurement. However they vary differently with VA and patiet-related factors. Higher SVCS was associated with lower DU and TD-Qas. DU-Qas values were more sensitive to changes in SCVS giving this method an advantage towards the indirect one. Adding to this, simple and inexpensive methods such as SVCS may be used to increase importante information that may be relevant for new surveillance recommendations (at least on high risk groups) helping guiding therapeutic interventions. Volume 29 | Supplement 3 | May 2014 IMPACT OF UNPLANNED DIALYSIS ON PROVISION OF VASCULAR ACCESS IN A REGIONAL DIALYSIS UNIT OVER A ONE YEAR PERIOD David Rees1, Clare Parker1, Paula Davies1, Sue Taylor1 and Ashraf Mikhail1 Morriston Hospital, Swansea, United Kingdom 1 Introduction and Aims: The use of temporary venous catheters are associated with increased morbidity, mortality and economic cost in comparison to arteriovenous fistula. The British Renal Association strongly recommends that 65% of all incident haemodialysis patients should commence dialysis with an arteriovenous fistula (AVF), and 85% of all prevalent patients should receive dialysis via an AVF. We have examined the impact of unplanned dialysis on compliance to these recommendations in a regional dialysis unit. Methods: A retrospective analysis using the regional renal database was conducted on patients who commenced dialysis over a one year period. Patients with established renal failure who were known to a nephrologist for greater than 90 days were compared to those known for less than 90 days (‘crash landers’). Patients known to a nephrologist for more than 90 days who commenced dialysis with temporary venous access were also examined in more detail. Results: Results were analysed for each quarter (Table 1). On inclusion of crash landers both incident and prevalent data fell short of national targets for patients dialysing with AVF. However, on exclusion of crash landers the percentage target for incident and prevalent data over one year was achieved.Twenty patients previously known to a nephrologist were identified as requiring dialysis through temporary access. Six patients due to rapid decline or an acute episode, five patients due to a change in modality, three patients as a result of non-engagement with treatment, three patients as a consequence of late referral from a nephrologist to the vascular access team, and one patient for both AVF immaturity and patient relocation. In one patient's case the reason was not known. SP554 Table 1: Impact of crash landers on compliance to national guidelines Incident patients CL= crash landers Oct-Dec 2012 Jan-Mar 2013 Apr-Jun 2013 Jul-Sept 2013 Average% Prevalent patients Total number commencing haemodialysis (excluding CL) 19 (10) Percentage commencing haemodialysis with AVF(excluding CL) 47.4 (90) Total number receiving haemodialysis (excluding CL) 339 (330) Percentage dialysing with AVF (excluding CL) 83.2 (85.5) 18 (8) 22.2 (44.4) 334 (324) 82.6 (84.9) 33 (23) 48.5 (66.7) 331 (321) 84 (86.3) 28 (20) 39.3 (57.9) 337 (329) 83.4 (85.7) 39.3 (64.7) 83.2 (85.6) doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 SP551 Introduction and Aims: Current guidelines recommend native arterio-venous fistulas (AVF) as the vascular access of choice for hemodialysis on account of the lower incidence of complications. However, this kind of vascular access has a high rate of early failure (early thrombosis or non-maturation). The aim was of our study to determine whether clear risk factors for early AVF failure could be identified in our patients. Methods: Data of all patients who underwent creation of an AVF at the Moscow Regional Research Institut from January 2003 to December 2013 were reviewed. Early failure was defined as a non-functioning fistula (thrombosis or absence of fistula maturation). Results: 519 patients underwent the creation of 548 native AVF, 327 (59.5%) in the forearm and 221 (40.5%) in the upper arm. 168 (32.4%) fistulae were created in diabetic patients. In a multiple logistic regression analysis, significant predictive factors of early failure were a distal location (odds ratio - OR) = 8.21, 95% CI = 2.63-25.63, p < 0.001), female gender (OR = 4.04, 95% CI = 1.44-11.30, p = 0.008), level of surgical expertise (OR = 3.97, 95% CI = 1.39-11.32, p = 0.010) and diabetes mellitus (OR = 3.19, 95% CI = 1.17-8.71, p = 0.024). Conclusions: Early failure of AVF occurs mainly in forearm sites among women and diabetic patients. Surgical expertise has also a significant influence. These results suggest that selection of a distal site for a native AVF has to be rigorously made for women and diabetic patients and that surgeon's dedication is of primary importance to avoid early AVF failure occurrence. Abstracts Conclusions: Compliance with national guidelines was achieved when patients previously unknown to a nephrologist were excluded from incident and prevalent data. Therefore, in future audits of this nature the question arises whether crash landers should be included. Rapid decline or patient factors were the most significant causes of previously known patients commencing dialysis with temporary access. Further examination of the factors leading to late presentation for dialysis may improve compliance with guidelines and patient outcomes. SP555 DIGITAL SUBTRACTION VENOGRAPHY USING A STEPPING TECHNIQUE FOR VENOUS MAPPING PRIOR TO HEMODIALYSIS VASCULAR ACCESS CREATION Introduction and Aims: Upper extremity venography is one of the methods usually used in venous mapping for further optimization of the surgical strategy. With reduction in dose of contrast media and radiation, preservation of venographic image quality is valuable although a challenge in clinical applications.We introduce a new bolus tracking venography method using a stepping-gantry technique for venous mapping before hemodialysis vascular access creation. Methods: Between January 2012 and October 2012, we analyzed the digital subtraction venography data sets of ten patients with end-stage renal disease (ESRD). Digital subtraction venography using a stepping-gantry technique representsa simple modification of the conventional stepping-gantry angiographyapplicable to the upper extremity. The examinations were reviewed by two radiologists in order to ascertain the opacification quality of the venographic images. We also assessed the amount of the dose of contrast media used as well as the radiation exposure dose during the venography. Results: Two radiologists examined the opacification quality, and more than 84% of the analyzed veins of the patients were graded as good regarding visualization of the cephalic vein of the forearm, the cephalic and basilic veins of the upper arm, and the subclavian vein. The average dose of contrast medium used in ten patients was 10.6 mL (range 10-12 mL), and the mean accumulated dose during the examination was 3.5 mGy (range 2-5.2 mGy). Conclusions: Preliminary findings indicates that single bolus stepping-gantry venography may be a valuable and alternative method for venous mapping prior to hemodialysis vascular access creation as it uses less contrast media and reduces the radiation dose. with an AVF/G, the majority (61%) of those surviving the first year converted to an AVF/G, resulting in a favorable increase in the prevalence of AVF/G from 51% to 81% during the first year on HD. The conversion rate was not influenced by patient's gender, age or presence of diabetes. The mortality during the first year (including incident day 1 patients) in the group starting with a catheter was significantly higher, which is most likely the result of a selection bias. All efforts should be made to provide patients with AVF/G before or at least soon after starting chronic hemodialysis. SP557 Ursula Hadimeri1, Anna VB Wärme1 and Bernd Stegmayr2 1 Skaraborg Hospital, Skövde, Sweden, 2Umea University, Umea, Sweden Introduction and Aims: A native arterio-venous fistula (AVF) is the best alternative for access in patients on chronic hemodialysis. However, its patency is often limited, because of complications, such as stenosis, thrombosis or infection. Both surgical and medical methods has been evaluated through the years, to avoid often painful and costly interventions. In recent years a few studies have shown positive effect on blood flow and patency of Far Infarred light (FIR) in the AVF. The primary aims of this study was to evaluate if a single treatment, using FIR, may alter blood flow rate and AVF diameter. This is to our knowledge the first study evaluating flow rate and diameter of AVF in patients with kidney disease. Methods: 30 patients with native AVF(end to side)located in the forearm were examined. Ultrasound was performed over three measure points in the AVF segment, followed by one FIR treatment for 40 minutes. A new ultrasound investigation was performed immediately after FIR. The results were collected simultaneously with current inflammatory status and demographic data. Results: The AVF flow rate increased after FIR treatment (mean 2.1+/- 1 cm/sec to 2.3 +/-1,p=0.022) while the proximal and distal AVF flow rate did not change. The diameter of the distal AVF became wider(0.72+/- 0.2 to 0.8 +/- 0.2, p= 0.006). The change in AVF flow rate was not different in those with or without diabetes mellitus, hemodialysis or between men and women.The mean arterial pressure, systolic and diastolic blood pressure did not change. The pulse decreased(from a mean of 72 +/- 9.8 beats/min to 68+/- 9.4, p= 0.043). Conclusions: This study shows that a single treatment,using FIR, increased blood flow rate and AVF diameter. It seems wortwhile to perform further studies to clarify long term benefits of FIR. SP558 SP556 CONVERSION OF VASCULAR ACCESS TYPE DURING THE FIRST YEAR ON HEMODIALYSIS: DATA FROM A NATIONAL REGISTRY A SINGLE TREATMENT, USING FAR INFRARED LIGHT, INCREASED BLOOD FLOW AND AV-FISTULA DIAMETER. GLUTATHIONE S TRANSFERASE GENE POLYMORPHISM IN HAEMODIALYSIS PATIENTS: INFLUENCE ON VASCULAR ACCESS SURVIVAL Jakob Gubensek1, Vanja Persic1, Barbara Vajdic1, Rafael Ponikvar1 and Jadranka Buturovic-Ponikvar1 1 University Medical Center Ljubljana, Ljubljana, Slovenia Aleksandar Jankovic1, Sonja Suvakov2, Jelena Tosic1, Tatjana Damjanovic1, Petar Djuric1, Sanja Bajcetic1, Vesna Radovic-Maslarevic1, Jovan Popovic1, Tatjana Simic2 and Nada Dimkovic1 1 Zvezdara University Medical Center, Belgrade, Serbia, 2Institute of Medical and Clinical Biochemistry, Faculty of Medicine, Belgrade University, Belgrade, Serbia Introduction and Aims: Although arterio-venous fistula or graft (AVF/G) is the optimal vascular access for hemodialysis and should ideally be created before a planned start of maintenance hemodialysis (HD), many patients start HD with a catheter. Limited data exists on the vascular access conversion rates during the first year on HD. We analyzed conversion rates during the first year on HD and factors affecting conversion on a subset of a national cohort. Methods: Data collected in the national renal replacement therapy registry was used. Since vascular access at initiation of HD is not recorded in the Registry, we included only patients starting HD in the last three months of the years 2006 - 2010 and used the vascular access reported at the end of the first year (i.e. 0-3 months after initiation of HD) as access at HD initiation. Vascular access at the end of the next calendar year was recorded and conversion rates between different access types were calculated. The effect of gender, diabetes and age (above or below median value) was estimated using Chi-square test. Results: 270 patients started hemodialysis in the specified periods (including day 1 patients), 139 (51%) with AVF/G, 126 (47%) with a catheter and for 5 (2%) data was missing. Mean age of patients was 65±15 years, 63% were male and 37% had diabetes. Patients starting with catheter were not different in age (67±15 vs. 64±15, p = 0.17) or presence of diabetes. After one year 77 (29%) patients died. Of the surviving 193 patients, 156 (81%) were dialyzed using AVF/G, 30 (16%) with a catheter and for 7 (3%) data was missing. When only the 126 patients starting chronic HD with a catheter were analyzed, 52 (41%) died within the first year and of the surviving 74 patients 45 (61%) converted to AVF/G after one year, 24 (32%) remained on catheter and for 5 (7%) data was missing. Whether the patient converted to AVF/G within the first year on HD was not influenced by patient's gender, presence of diabetes or age ≥70 years (median age). Of the 139 patients starting with AVF/G 21 (15%) died ( p < 0.001 vs. catheter group); of the remaining 118, only 6 (5%) converted to catheter after one year. Conclusions: To conclude, although only half of the incident patients started HD Introduction and Aims: Functional, long-lasting vascular access (VA) is essential for maintaining effective long-term haemodialysis (HD). Given the importance of the role that AV access have in maintenance of HD treatment, there is a constant need to find out the causes of its failure/survival. Glutathione S transferase (GSTs) are group of enzymes that have an ability to catalyze the conjuction of the reduced form of glutathione to xenobiotic substrates for the purpose of detoxification and therefore have an important role in the protection of oxidative damage. The aim of this study was to analyze GSTs gene polymorphism in haemodialysis patients and to determine possible influence of glutathione s-trasferase (GST) A1, M1, P1 and T1 enzyme gene polymorphysm on AV access survival. Methods: This cross-sectional study included 136 patients treated by chronic HD three times per week on polysulphone membranes for more than six months. They were divided into two groups: group 1-patients without vascular access failure (No=70); group 2-patients with at least one vasular access failure (No=66). Results: In our group of patients, regarding GSTM 1: 58 patients have at least one active allele present, 78 have no active allele present; regarding GSTT 1: 89 have at least one active allele present, 47 have no active allele present. In GSTP 1 frequences are: ile/ ile 50 patients, ile/val 55 patients, val/val 31 patients and in GSTA 1 are: CC 48 patients, CT 59 patients and TT 29 patients. By performing logistic regression it was shown that patients with val allele in GSTP gene experienced 1.7 folds higher risk for developing AV access failure ( p=0.13), and the presence of T allele in GSTA gene led to twice higher risk for developing AV access failure which was near statistical significance ( p=0.06). Also, GSTT null genotype have shown 1.9 fold higher risk for AV access failure. Conclusions: Presence of val allele in GSTP gene, T allele in GSTA gene and GSTT null genotype increases risk for developing AV access failure. We need longer follow-up in order to get definitive conclusion about the influence of these gene polymorphisms on AV access failure and its importance in every-day clinical practice. iii | Abstracts Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 Young Ok Kim1, Sun Ae Yoon1, Young Soo Kim1, Su Jin Choi1, Ji Won Min1 and Myeong A Cheong2 1 Uijeongbu St. Mary’s Hospital, Uijeongbu-city, Republic of Korea, 2Korea Cancer Center Hospital, Seoul, Republic of Korea Nephrology Dialysis Transplantation Abstracts Nephrology Dialysis Transplantation SP559 IS IT WORTH TO BE AFRAID FROM METABOLIC SYNDROME IN HEMODIALYSIS PATIENTS REGARDING THE VASCULAR ACCESS SURVIVAL? Erjola Likaj1, Saimir Seferi1, Elizama Petrela1, Alma Idrizi1, Merita Rroji1, Myftar Barbullushi1 and Nestor Thereska1 1 UHC Mother Theresa, Tirana, Albania SP560 BUTTONHOLE CANNULATION VERSUS CONVENTIONAL ROPE LADDER CANNULATION ON NATIVE ARTERIOVENOUS FISTULA- A 1-YEAR STUDY ON INFECTION, THROMBOSIS, ANEURYSM AND PRIMARY ARTERIOVENOUS FISTULA PATENCY Hooi Lim Chua1, Harkerith Kanda1, Siew Lok See1 and Ngoh Chin Liew2 1 Mawar Hemodialysis Center, Seremban, Malaysia, 2University Putra Malaysia, Selangor Darul Ehsan, Malaysia Introduction and Aims: Buttonhole cannulation (BH) of arteriovenous fistula (AVF) has been reported to be superior to rope ladder cannulation (RL) in some studies in terms of inducing less pain, less aneurysm formation and improved patency. Recent studies however, have cautioned the potential for increased blood stream infection and septicemia. There were few reports in Asia on BH cannulation and the effect this would have on the smaller veins is unknown. The aim of this study was to compare the medium term outcomes of this method to the conventional RL cannulation on frequency of infection, thrombosis, aneurysm formation and primary patency of AVF. Methods: A one year prospective cohort study was conducted in Mawar Hemodialysis Center from 18/7/2012- 17/7/2013. All patients with BH cannulation were included and matched with a group with conventional RL cannulation. The patients were followed up 3 monthly. The occurrence of infection, thrombosis and aneurysm formation was recorded. An aneurysm was defined clinically as venous dilatation of 3 times the native vein diameter. The data was analyzed, Kaplan-Meier survival curve for primary AVF patency in each group was plotted and compared using logrank test. Results: Total of 162 patients were include: 81 of BH and 81 of RL cannulation. The demographic data in the 2 groups was paired in terms of gender, age, race, co-morbidity and type of fistulas. Mean primary AVF patency: 890 days in BH group versus 940 days in RL group. Number of deaths and transfer out: 13 (16.0%) versus 11 (13.6%). Frequency of infections: Cannulation site infection without fever, settled with oral antibiotics- 0.14 per 1000 AVF days versus 0.07 per 1000 AVF days ( p=0.6816)), cannulation site infection with fever, settled with intravenous antibiotics 0.1 per 1000 AVF days versus 0.07 per 1000 AVF days ( p=1.0000). Frequency of thrombosis: 0.06 per patient-year in both groups ( p=1.000). Aneurysm: 9 versus 22 ( p= 0.0156). Primary AVF patency: 97.3%, 93.1% at 6 months and 1 year in BH versus 97.5%, 93.5% in RL ( p=0.9596). Volume 29 | Supplement 3 | May 2014 SP561 VASCULAR ACCESS FOR LONG-TERM HEMODIALYSIS/ HEMODIAFILTRATION PATIENTS Kenji Tsuchida1, Tadashi Tomo2, Mizuya Fukasawa3, Shu Kawashima1 and Jun Minakuchi1 1 Kawashima Hospital, Tokushima City, Japan, 2Oita University, Oita City, Japan, 3 Yamanashi University, Koufu, Japan Introduction and Aims: In Japan, patients are often on long-term hemodialysis(HD) /hemodiafiltration(HDF) treatment. Vascular access is a lifeline for dialysis patients and the proper maintenance of vascular access is one of the key factors that make long-term HD/HDF possible. In this study, we investigated the conditions of vascular access in the patients undergoing the chronic HD/HDF in our hospital group to examine the relationship between vascular access and long-term treatment. Methods: We studied the conditions of vascular access in 912 patients who were receiving the chronic HD/HDF including those who had been on dialysis treatment over 20 years as of December 2013. Results: There were 125 patients who had been on dialysis treatment over 20 years, the longest being 38 years, which accounted for 13.7 percent of the total. The primary diseases were: two cases of diabetes and the rest were chronic glomerulonephritis. There were 105 patients with AVF while there were only 20 with AVG (16.0 percent). However, as for the 774 patients who had been on dialysis treatment for less than 20 years, 91 patients had AVG (11.7 percent), which indicated the increase in the rate of AVG along with the prolongation of dialysis treatment. Conclusions: The method of access mainly used for patients who had been on dialysis treatment over 20 years, which is very rare even on a global scale, was AVF. However, it is unavoidable to shift to AVG for the cases of vein deterioration due to long-term usage. The method of access using AVG on long-term patients is expected to further increase. SP562 USE OF CEFUROXIME IN TREATMENT OF METHICILLIN SENSITIVE STAPHYLOCOCCUS AUREUSIN HAEMODIALYSIS PATIENT - A SINGLE CENTRE EXPERIENCE Vijay Thanaraj1 and Ajay Dhaygude1 Lancashire Teaching Hospital NHS Foundation Trust, Preston, United Kingdom 1 Introduction and Aims: Infection is one of the most common causes of mortality in haemodialysis patient especially in patients who dialyse via catheter1. It is common practice to use Vancomycin in management of Methicillin sensitive Staphylococcus aureus (MSSA) infection because of the broad-spectrum cover and convenience of administration in haemodialysis patients3. Flucloxacillin is an effective alternative but q.i.d. dosing poses compliance problem. Use of Vancomycin however is associated with number of limitations. The incidence of Vancomycin resistant Enterococcus (VRE) is on the rise2. In our centre 10 patients with VRE were reported in last 12 months. It is less bactericidal compared with the cephalosporins and penicillins. Close monitoring of levels is required to prevent toxicity. Cefuroxime, a second generation Cephalosporin is effective against MSSA and offers advantage over Vancomycin as above. Methods: We used intravenous Cefuroxime; 1.5 grams given at the end of each dialysis session for a period of four weeks in patients with MSSA infection in haemodialysis patients. Root cause analysis and appropriate investigations were done for all the patients with MSSA infection to exclude other potential sources of infection apart from dialysis catheter. Repeat blood cultures and exit site swab were taken following treatment to exclude ongoing bacteraemia. Ten patients were diagnosed with MSSA infection between December 2009 to March 2013. They were dialysing with tunnelled dialysis catheter. All the patients were treated with cefuroxime after excluding penicillin allergy. Results: None of the 10 patients, who were treated with Cefuroxime, relapsed following completion of the course of treatment. The mean follow up period was 398 days. Conclusions: In this study Cefuroxime appears to be safe and effective alternative in management of MSSA infection in haemodialysis patients. First generation cephalosporin (cefazolin) has been used successfully3, use of second generation cefuroxime has not been reported before. Although small number of patients were treated with cefuroxime, unlike cefazolin, we did not find any treatment failure and it may be superior to 1st generation cephalosporins.Our study has small number of patients however we are proactive with ‘fistula first’ policy and incidence of catheter associated infections are very low in our centre. Further large studies are recommended. doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 Introduction and Aims: Albania is a developing country and the caracteristics of all our population are expressed in the hemodialysis patients too. The metabolic syndrome is prevalent in this category of patients as well as in the general population. The change of lifestyle, the food that is more and more caloric and salty, the possibility of having an enormous variety of food in contrary of that limited during the communism period and the fenomenon of “fast-foodism” are responsable in most cases of metabolic syndrome.The natural history of patients with metabolic syndrome (MetS) undergoing hemodialysis access placement is unknown. MetS has previously been found as a risk factor for poor outcomes for vascular surgery patients undergoing other interventions. The aim of the study is to describe the outcomes of MetS patients undergoing primary hemodialysis access placement. Methods: The medical records of the 104 patients who underwent hemodialysis access placement between 2009 and 2013 were collected. Survival, primary patency, and secondary patency were evaluated using the Gehan- Breslow test for survival. MetS was defined as the presence of three or more of the following: blood pressure≥130/90 mm Hg; triglycerides≥150 mg/dl; high-density lipoprotein≤50 mg/dl for women and ≤40 mg/dl for men; body mass index≥30 kg/m2; or fasting blood glucose≥110 mg/dL, uricemia>7mg/dl. Results: Of the 104 patients who underwent hemodialysis access placement, 23.2 (%) were identified to have MetS. The distribution of MetS factors among all patients was hypertension in 57.67%, diabetes in 17.48%, elevated triclyceride in 34.66%, decreased high-density lipoprotein in 65.3%, elevated body mass index in 11.65%, elevated uricemia 13.59%. Patients mean age was 48,27 ±12,18 years. The median length of follow-up was 4 years. The forearm was site of fistula placement in 63%; The binary logistic regression showed no difference between groups (MetS, 57%; no MetS, 50%; P=.388). The median time to primary failure was 0.68 years for all patients (MetS, 0.555 years; no MetS, 0.436 years; P=.255). Secondary patency was 50% at 1.18 years for all patients (no MetS, 1.94 years; MetS, 0.72 years; P=.024). Median survival duration for all patients was 4.15 years (no MetS, 5.07 years; MetS, 3.63 years; P=.019). Conclusions: MetS is prevalent among patients undergoing hemodialysis access placement. Patients with MetS have equivalent primary patency rates; however, their survival and cumulative patency rates are significantly lower than in patients without MetS. Patients with MetS form a high-risk group that needs intensive surveillance protocols. Conclusions: BH cannulation method appeared to have less aneurysm formation. The 2 groups did not differ significantly in the frequency of infection, thrombosis and primary AVF patency at 6 months and 1 year. If all things being equal, BH cannulation method, requiring lesser length of vein for cannulation would appear to be advantageous to RL cannulation in the medium term. A randomized controlled trial is however needed to confirm the study outcome. Abstracts SP563 NEW LOW PRESSURE TECHNIQUE (LPT) TO IMPROVE PATENCY PERIOD Kiyoshi Ikeda1 1 Dr., Fukuoka-ken, Japan SP564 INITIAL EXPERIENCE WITH VENOUS WINDOW NEEDLE GUIDE - VITAL ACCESS- TO ASSIST IN CANNULATION OF DIFFICULT ARTERIOVENOUS FISTULAE IN AN ITALIAN HEMODIALYSIS CENTER Giacomo Forneris1, Pasqualina Cecere1, Marco Pozzato1, Marco Trogolo1, Antonella Vallero1, Paola Mesiano1 and Dario Roccatello1,1,2 1 Ospedale San Giovanni Bosco, Turin, Italy, 2Università Di Torino, Turin, Italy Introduction and Aims: Aim of this work was to describe the first results on the use of a new totally implantable device for patients in whom native fistula was difficult to cannulate due to its depth or site. This device enable the use of buttonhole cannulation technique. We describe three patients in whom the device was implanted from October 2012 to March 2013. Methods: "Venous Window Needle Guide" (VWING) (Fig.1) was implanted subcutaneously and attached to the exterior fistula wall utilizing a surgical cut-down technique and sutured to secure the implant to the fistula. The device remained in this extra-vascular, palpable subcutaneous position, facilitating access to the fistula. The VWING was indicated for use on a mature AV fistula too deep or too tortouous or mobile for a standar cannulation. Results: Two patients had diabetes. Native fistulae, radio-cephalic in all cases, were too deep for traditional cannulation and were mature at the time of insertion of the device. Surgical procedures, lasting about 30 minutes each, were preformed under local anaesthesia and without complications. In one patient two devices were implanted, while in the other two patients only one device each. After 45 and 42 days respectively of healing period, the VWING sites were cannulated. Two patients are still using the device for dialysis, while the third is so far on conservative treatment. First cannulations were performed using a sharp needle to create a scar tissue tunnel track, SP564 iii | Abstracts then transition to blunt needles was made according to buttonhole technique. The cannulation techniques required a short learning curve and was well accepted by patients due to reduced incidence of pain and fewer attempts to successfully cannulate the fistula. After a period of follow-up of 16 months no major complications were observed. Conclusions: The VWING represents a new device for access to difficult to cannulate fistulae, with a simple technique of implantation and use, allowing use of butthonhole technique that may reduce trauma and damage to the fistula. Further studies are needed to demonstrate the safety and efficacy of the vascular needle guide. SP565 FALLOW UP, PROTECTION DETAILS OF 902 FISTULAS BY ASPECT OF CENTRAL VENOUS CATHETER USE AND SURVIVES OF AV FISTULAS Mustafa Esentürk1, Murat Zengin2 and Lezan Keskin1 1 Malatya State Hospital, Malatya, Turkey, 2Fresenius MLTY, Malatya, Turkey Introduction and Aims: We aimed to increase AV fistulas usage and to decrease CVC and Graft usage. We obey all the rules described on DOQI except time management at first usage. By this way we try to catch an alternative aspect. Methods: In our study we investigate 902 fistula opened by the same surgeon between 31.12.2004-31.12.2013 by the aspect of first canulation time, type, survives of patients and fistulas. In 902 AV fistulas 260 (28.8%) were diabetic, 447 (49.6%) were primary AV fistulas.The Youngest was 12 and the oldest was 95 years old. Average was 58.6. 528 (58.5%) were male, 547 (60.6%) left handed (non-dominant). 647 (71.7%) were Brescia-Cimino, 889 (98.6%) opened by side to side technique. 699 (77.5%) cases were opened from distal site of forearm. (Yates corrected chi-square test and Fishers used in all calculations) Results: 268 (29.7%) patients were taken in first 24 hrs. by new fistulas. 438 (48.6%) in first 30 days were taken to dialysis by new fistulas without use of catheters.First Canulation time of 902 Patients First canulating time 0-24 hrs Catheters Maturasyon 2-30 day grup Predialysis grup Fail, up-non fallowed No of cases 268 417 170 42 5 percentage% 29.7 46.2 18.9 4.6 0.6 Conclusions: Fistula survives were found in publications as 45.6% in AVF and 39.6% in CVC in 3 years fallow up. In our study we found 44.8% and 46.2% (Group A and group C) early and late canulated groups without using any type of catheters in 5 years. Also dramatically low survive in catherised group B (13.8% p=0.001). Mortality was found 11.7% in AVF and 16.1% in catheter group in 27 months. In our study we found 19.1% and 18.8% in A and C group in 60 months.And also 26.2% in catheterized group. ( p=0.0033 and p=0.0028).There were no differentiations between group A, B and C by the aspect of Kt/V, and URR (dialysis adequacy, p>0.05).Publications are focused on low catheter usage (less than 10% of patients).We found better fistula SP565 SP565 Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 Introduction and Aims: At this conference two years ago we presented our findings on low pressure VAIVT. Although our findings using low pressure were very encouraging, when using high pressure for full expansion the time of stenosis for intimal hypertrophy and intimal injury occurring shortened significantly. Determining the placement of the end point depends on whether your aim is VAIVT for full expansion or dialysis blood flow rate.This study presents our findings on data collected over a 39 month period on our low pressure methods, the balloon specifications, and how they effected the patency period. Methods: Study: Data from September 2010 to November 2013 on 798 VAIVT Cases was collected.Ratio: AV-f : AV-g, 505 : 293 We used the Kaplan Meier Method and Log-rank Test taking into consideration balloon size, balloon specifications, and average atmosphere and the effects they had on Patency PeriodThe LPT consists of starting the balloon at 1 atmosphere and repeating inflation and deflation 20 to 30 times over 1 minute intervals increasing 1 atmosphere each interval.Technique End Point having a dialysis blood flow rate of 500ml/min or more is acceptable, noting that full dilation is not the main objective. LPT uses nominal pressure as the maximum standard. Results: The patency of performing dilation was 92%/3 months, 68%/6 months.AV-f cases using super-non-compliance balloon (CONQUEST®, Yoroi®) showed a significant difference in the patency period over non-compliance balloons. (80%/1year vs 52%/1year, p<0.001, Kaplan Meier methods, Log-rank tests) no significant difference in pressure 7.9 atmosphere vs 8.0 atmosphere was observed. As for AV-g cases using both types of balloons, there was no significant difference in the Patency period. Conclusions: 1) Dog-bone phenomenon can be avoided by using a super-non-compliance balloon. 2) LPT, using nominal pressure, resulted in very good patency period. 3) LPT prevents intimal injury, and vein damage. Nephrology Dialysis Transplantation Abstracts Nephrology Dialysis Transplantation SP565 FIRST CANULATION TIME: 902 PATIENTS First canulating time No of cases percentage% 0-24 hrs 268 29.7 Maturasyon 2-30 Catheters day grup 417 170 46.2 18.9 Predialysis grup 42 4.6 Fail up-non fallowed 5 0.6 SP565 A-V FISTULA MORTALTY RATE Canulation site and time 1 YEAR 2 YEARS 3 YEARS 4 YEARS 5 YEARS 3.3 7.5 9.6 12.3 15.2 19.1 2.9 8.1 12.8 17.7 21.8 26.2 3.0 6.1 9.8 11.7 16.2 18.8 survives in fistula starting dialysis group than catheter used group. And lower mortality rate than catheter used group. We emphasize that if there is enough maturation and blood flow early fistula canulation by obeying other rules lowers mortality and morbidity rate and deathly complications ratio. This also leads to lower cost. SP566 DUPLEX ULTRASOUND AND ARTERIOVENOUS GRAFTS: PREOPERATIVE MAPPING AND POSTOPERATIVE SURVEILLANCE Giuliana Loizzo1, Sara M Viganò2, Giuseppe Bacchini2, Elena Rocchi2, Valeria Sala2 and Giuseppe Pontoriero2 1 University of Bari, Bari, Italy, 2A. Manzoni Hospital, Lecco, Italy Introduction and Aims: Hemodialysis vascular access dysfunction is responsible for more than 40% of the hospitalizations among patients with end-stage kidney disease. Especially synthetic grafts (AVGs) are associated with an increased rate of morbidity, mortality and cost of health care. Thus, to improve the managing of the vascular access and to avoid the complications related, particularly grafts's thrombosis, several protocols have been performed. According to the data reported in the literature the average of the primary patency rate of an AVG is approximately 10 months. Periodic monitoring of vascular access with duplex ultrasound has been demonstrated to be able to identify early access dysfunction, thus anticipating surgical intervention and improving its long-term survival.Aim of this study is to evaluate the application of duplex ultrasound in the surveillance and endovascular treatment of the complications of AVGs . Methods: Data of this study were collected retrospectively from 1997. During sixteen years (192 months) of follow-up, we have placed 177 synthetic grafts in 136 patients at our institution. Nowadays we are following a protocol based on periodic (37±12 days) ultrasound monitoring of the AVGs and it even provides, when necessary, a prompt ultrasound guided by PTA and/or mechanical thrombolysis. Results: 57.6% of the grafts were placed in the forearm, 41.8% in the arm , 0.6% in the thigh. We used different types of grafts: PTFE (33.9%) , modified PTFE (48.1%), bovine (16.9%) and polycarbonate (1.1%). 17 grafts (9.6%) have gone on early failure (within 30 days of the surgery) due to patient or surgical complications. In the remaining 160, the mean primary and secondary patency rates were 23 months and 30.4 months, respectively. To obtain these results, we performed 575 ultrasound guided PTA (1.44 PTA/pts/year). In 55 patients (34.4%) the PTA has been associated with the placement of one or more stents and in 60 cases (37.5%) we used the cutting balloon. Furthermore, with ultrasound guided technique, we carried out 79 thrombolysis, associated or not to PTA. All the operations were performed in outpatient surgery. Conclusions: The application of the duplex ultrasound in the endovascular surgery and follow up of the AVGs represents a useful and safe policy for the patients, and an economical one for the health care system ( it doesn’t required patients’ hospitalization so it means to save at least 1000 € for each procedures). This study should emphasize the role of duplex ultrasound: preoperative, for the vascular mapping and postoperative, for the surveillance of the AVGs, early diagnosis and prompt treatment of the complications. SP567 THE MEANING AND IMPLICATIONS OF HAEMODIALYSIS VASCULAR ACCESS FROM THE PATIENTS' PERSPECTIVE: THEMATIC SYNTHESIS OF QUALITATIVE STUDIES Jordan R Casey1, Camilla S Hanson1, Wolfgang C Winkelmayer2, Jonathan Craig1, Suetonia Palmer3, Giovanni Strippoli4 and Allison Tong1 1 The University of Sydney, Sydney, Australia, 2Stanford University, Palo Alto, CA, 3 University of Otago, Christchurch, New Zealand, 4Diaverum, Lund, Sweden Volume 29 | Supplement 3 | May 2014 SP567 SP568 UNUSUAL VASCULAR ACCESS FOR HEMODIALYSIS, AN IMPORTANT RESOURCE. Domenico Ferrara1, S. Scamarda, L. Bernardino, L. Amico, M.C. Lorito, f. Incalcaterra, L. Visconti, G. Visconti, Franco Valenza1 and F. D’Amato 1 Hospital Villa Sofia-Cervello, Palermo, Italy Introduction and Aims: The vascular access for hemodialysis sometimes presents complications that may affect its functionality and patency and these are being quite frequent.The increase in average age of the hemodialysis population is probably major cause of the loss of the most common sites for vascular access. In these patients it is necessary to select insertion sites for access tunneled CVC that are usually unfamiliar to the nephrologist, as iliac veins, inferior vena cava. Methods: In a few patients referred to our center over the past two years, vascular accesses became worn out, for several reasons (FAV trombosis, vein trombosis, CVC trombosis).In these circumstances we have excluded to swith to peritoneal dialysis, and opted instead for cannulation sites such as the large caliber abdominal veins. Nephrologists do not usually make use of such sites.Our experience consists of four patients, to whose were positioned tunneled CVC (only one Tesio catheter)in the abdominal veins, the iliac vein and the translumbar inferior vena cava, because it was impossible to use the circulation of the superior vena cava. Results: The average age of the four patients was 70 ± 11 years , the average age of dialysis was 3.4 years, the distribution of cannulation sites was: 75% in the right iliac vein (3 patients), 25% in the inferior vena cava via right trans-lumbar (one patient).The doi:10.1093/ndt/gfu156 | iii Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 GROUP A: 268 (29.7%) cases GROUP B: 417(46.2%) cases GROUP C: 170(18.9%)%) case 1 WEEK Introduction and Aims: Vascular access complications are associated with increased mortality and contribute to 20% of hospitalisations in patients on haemodialysis. While arteriovenous fistula (AVF) are associated with better clinical and quality of life outcomes compared with other access types, patient refusal is a key barrier to creating a mature AVF. Also, concerns about vascular access are a major treatment-related stressor for patients. We aimed to describe patients’ experiences and perspectives on vascular access initiation and maintenance in haemodialysis. Methods: MEDLINE, Embase, PsycINFO, CINAHL, reference lists and PhD dissertations were searched to December 2013. Qualitative studies that assessed the experiences and attitudes of patients with chronic kidney disease (CKD) on vascular access (arteriovenous fistula, arteriovenous graft, central venous catheter) were synthesized thematically. Results: Forty-six studies involving over 1034 patients (haemodialysis [n≥761]; peritoneal dialysis [n≥67]; non-dialysis dependent [n≥42]; unspecified modality [n≥164]) were included. Six major themes were identified: heightened vulnerability (bodily intrusion, fear of cannulation, threat of complications and failure, unpreparedness, dependence on a lifeline, wary of unfamiliar providers); disfigurement ( preserving normal appearance, visual reminder of disease, avoiding stigma); mechanisation of the body (bonded to a machine, internal abnormality, constant maintenance); impinging on way of life ( physical incapacitation, instigating family tension, wasting time, added expense); self-preservation and ownership (task-focused control, advocating for protection, acceptance); and confronting decisions and consequences (imminence of dialysis, existential thoughts). The conceptual links among themes are depicted in the Figure. Apparent differences across types of access were primarily related to complications: clotting, infiltration and stenosis were emphasised with the use fistulas and grafts, whereas infections were a predominant concern in catheter use. Conclusions: Some patients’ perceive vascular access as disruptive to their identity, rendering them physically and emotionally vulnerable, and causing debilitating social consequences. To cope, they devise personal strategies to safeguard their vascular access site, self-advocate, preserve a normal appearance, and take a proactive stance in managing their medical responsibilities. Timely education and counselling about vascular access, building patients’ trust in health-care providers, and psychosocial interventions focussed on resolving vascular-access related anxieties are suggested to increase AVF use, quality of dialysis, and treatment satisfaction. This may lead to better outcomes for patients with CKD requiring haemodialysis. Abstracts Nephrology Dialysis Transplantation SP568 large abdominal vessels were cannulated with CVC which were tunnelled in the angiography suite with the help of interventional radiologists.After twenty months (20 ±5)of follow-up the tunnelled CVCs are well-functioning and do not show complications such as thrombosis and infection. Conclusions: These data confirm that in the complex cases the option of unusualy cannulation sites for tunnelled CVC, like inferior vena cava and iliac veins, is an important resource.These sites are also safe and long lasting, as demonstrated by the follow-up (20 months) and the absence of complications SP569 SURVIVAL AMONG CHRONIC HEMODIALYSIS PATIENTS FOR EACH TYPE OF FIRST VASCULAR ACCESS Anteo Di Napoli1, Luigi Tazza2, Serena Chicca3, Enrica Lapucci1, Patrizia Silvestri2, Domenico Di Lallo3, Paola Michelozzi1 and Marina Davoli1 1 Lazio Regional Health Service, Rome, Italy, 2Catholic University, Rome, Italy, 3 Lazio Regional Health Authority, Rome, Italy Introduction and Aims: Many studies evaluated outcomes associated with undergoing chronic hemodialysis (CHD) with native arteriovenous fistula (nAVF) instead of venous catheter (VC) as first vascular access, while few studies were focused about outcomes associated with more specific types of vascular access. We classified nAVF as first distal nAVF, or second time distal nAVF, or upper arm nAVF; we classified VC as temporary VC, or as VC with subcutaneous tunnel; arteriovenous grafts (AVG) were separately considered. Our study aimed to evaluate survival differences between incident patients according to this vascular access classification. iii | Abstracts Methods: Retrospective study was conducted in Lazio (Italian region with 5.7 million inhabitants) on 7,861 hemodialysis patients who underwent CHD (2002-2011), notified to Lazio Region Dialysis and Transplantation Registry. We used Kaplan-Meier method and performed a multiple Cox regression model, adjusted for: age, gender, self-sufficiency, nephropathy, comorbidities, serum levels of haemoglobin, albumin, creatinine, calcium and phosphorus. Results: Survival probability was 89.8% at 1 year and 62.1% at 5 years for patients who started CHD with first distal nAVF; 89.8% at 1 year and 59.8% at 5 years with second time distal nAVF; 87.0% at 1 year and 54.5% at 5 years with upper arm nAVF; 82.2% at 1 year and 49.4% at 5 years with AVG; 75.5% at 1 year and 48.3% at 5 years with temporary VC; 73.3% at 1 year and 38.6% at 5 years with VC with subcutaneous tunnel. Median survival probability was 94 months for patients who started CHD with first distal nAVF, 69 months with upper arm nAVF, 52 months with AVG, 55 months with temporary VC and 35 months with VC with subcutaneous tunnel. Compared with patients who started CHD with first distal nAVF we found a statistically significant higher mortality risk for subjects with temporary VC (HR=1.35; 95% CI:1.21-1.50) and VC with subcutaneous tunnel (HR=1.50; 95%CI:1.37-1.66); a not statistically significant higher mortality risk was found for upper arm nAVF (HR=1.12; 95%CI:0.96-1.31) and for AVG (HR=1.36; 95%CI:0.91-2.04). Conclusions: Our study, beyond to confirm higher mortality risk for subjects with a CV as first vascular access, suggests that upper arm nAVF and AVG are associated with clinical conditions predictive of worse outcomes. Thus particular attention is necessary for patients with types of vascular access associated with worse outcomes in term of mortality or morbidity. Our finding suggest to maximize distal nAVF use, also considering the worrying worldwide increase of VC through the last decade, reflecting changing in CHD population characteristics (ageing and more comorbidities), but also health services organization and dialysis unit staff policies. Volume 29 | Supplement 3 | May 2014 Downloaded from https://academic.oup.com/ndt/article-abstract/29/suppl_3/iii246/1882201 by guest on 17 June 2020 SP568