Joan Rivers' autopsy: Comedian died after complications during her routine surgery

Autopsy report noted that she died due to lack of oxygen to the brain

Joan Rivers arrives at the 55th Annual Primetime Emmy Awards in 2003 (AP)

Joan Rivers’ autopsy has revealed she died from complications due to surgery.

A report released by New York City Medical Examiner’s Office (OCME) said that she died due to lack of oxygen to her brain.

OCME spokesperson Julie Bolcer said: “The cause of Ms Rivers’ death is anoxic encephalopathy due to hypoxic arrest during laryngoscopy and upper gastrointestinal endoscopy with propofol sedation for evaluation of voice changes and gastroesophageal reflux disease. The manner of death is therapeutic complication”.

Ms Bolcer continued: “The classification of a death as a therapeutic complication means that the death resulted from a predictable complication of medical therapy."

The legendary comedian died in New York 4 September during a laryngoscopy, a procedure in which a doctor examines the back of the throat and vocal cords, and upper gastrointestinal endoscopy. The upper gastrointestinal tract is then examined with a light.

Her daughter Melissa Rivers said to The Hollywood Reporter: “We continue to be saddened by our tragic loss and grateful for the enormous outpouring of love and support from around the world. We have no further comment at this time.”

Ms Rivers was rushed to Mount Sinai Hospital, New York, after reportedly suffering cardiac arrest during the procedure.

The New York State Department of Health had launched an investigation into Rivers’ death, which has now been completed. A spokesperson confirmed the findings had been forwarded to the Federal Centers for Medicare and Medicaid Services (CMS).

A spokeswoman for Yorkville Endoscopy told The Hollywood Reporter in a statement: “HIPAA [privacy] laws prevent us from disclosing any information regarding patients.”