My mom went through something similar. She needed a knee replacement and her doctor wouldn’t okay it until she lost weight, which was difficult given the whole knee problem preventing her from walking thing. He told her she was too dangerous to operate on and that there were just too many risks.
My mom tried to lose weight in vain for months before she finally gave into my begging her to get a second opinion. The first doctor she saw next scheduled her for surgery the same day she met him. When my mom asked about the risk of operating on her he told her that there was some minor risks for complication and that all she would need to do to alleviate the risk was spend an extra night in the hospital so that they could keep a look out for any complications.
There were zero. There were also zero complications when she had her other knee done, her hip replaced and her gallbladder removed.
Almost like the first doctor was entirely full of shit and just trying to coerce his patient to lose weight by scaring her for fucking nothing, even when she was living day to day in excruciating pain and desperately needed a surgery.