According to a new report, a doctor performed an outpatient procedure on Joan Rivers that should ONLY have been performed in a hospital … and that’s what led to her death. According to the New York Daily News, during Rivers’ planned endoscopy … doctors discovered something on her vocal cord and her doctor decided he would biopsy it. During the biopsy Rivers’ vocal cords reportedly seized — slammed shut — cutting off her air supply. Medical experts told the Daily News … the biopsy was too risky for outpatient surgery and should have been performed in a hospital.