More than a month after Joan Rivers's death, a new report reveals the exact cause.

E!'s Fashion Police to Go On Without Joan Rivers

The comedian, whose career spanned almost 50 years, suffered from hypoxia during a throat procedure, which meant there was no oxygen traveling to her brain, TMZ reported on Thursday. In turn, she suffered from brain damage.

The New York City Office of Chief Medical Examiner, who called it a "predictable complication," also stated that Rivers was put to sleep with Propofol during the surgery.

Does Melissa Rivers Plan To Sue The Clinic?

According to the Medical Examiner, the surgery was intended to detect reasons for her voice change and to deal with her acid reflux.

The former Fashion Police host faced complications during the throat surgery performed in New York City on Aug. 28. Rivers went into cardiac arrest during the procedure and was rushed to Mount Sinai Hospital. She was kept on life support in the days that followed and passed away on Sept. 4 at the age of 81.

The comedian's daughter Melissa Rivers announced her mother's death with a touching statement.

"My mother's greatest joy in life was to make people laugh. Although that is difficult to do right now, I know her final wish would be that we return to laughing soon," she wrote.

Melissa later tweeted another heartfelt message. "My mother would have been overwhelmed by the scope and depth of the love that people have expressed for her. It is certainly helping to lift our spirits during this time," she wrote.  

Tags: Joan Rivers