NEW YORK (REUTERS) - Comedian Joan Rivers, who passed away last month at the age of 81, died of a complication during a medical procedure that caused oxygen deprivation to the brain, the New York chief medical examiner's office said on Thursday.
"The cause of Ms Rivers' death is anoxic encephalopathy due to hypoxic arrest during laryngoscopy and upper gastrointestinal endoscopy," it said in a statement, referring to brain damage due to lack oxygen.
"The manner of death is therapeutic complication," it added,"the death resulted from a predictable complication of medical therapy."
Rivers, the brash, pioneering comedian who paved the way for women in stand-up comedy, died on Sept 4 in a New York hospital a week after she stopped breathing during an outpatient medical procedure on her vocal cords.
Doctors were performing a laryngoscopy, an examination of the back of the throat and vocal cords, on the comedian after she had complained of problems with her voice.
Following her death, the State Health Department launched an investigation into the Yorkville Endoscopy Centre where Rivers was treated.
It reviewed records and documents and questioned doctors at the clinic which opened in 2013.
The clinic denied media reports that it had administered a general anaesthesia or conducted a vocal cord biopsy on Rivers.
Last month, the clinic said the doctor who performed the procedure was not currently working there or serving as its medical director.
Rivers was also known for numerous cosmetic procedures that she joked about in her comedy routines, and the catchphrase, "Can we talk?"
Her career as a stand-up comedian, author, talk show host and reality TV star spanned five decades.