It alleges that an unauthorised doctor carried out a procedure, and a staff member took a photo of Rivers on the operating table.
Her daughter Melissa said she was “outraged by the misconduct and mismanagement”.
Rivers was understood to be in good health when she entered the clinic on August 28 for an endoscopy after suffering chronic acid reflux, which had left her hoarse.
The report claims that while under anaesthetic, her vital signs began to deteriorate, but between 9.12am and 9.26am no action was taken.
Cardiopulmonary resuscitation was eventually started.
Yorkville said it had “implemented a plan of correction that addressed all issues raised.
“Physicians involved in the direct care referenced in the report no longer practice at Yorkville.”