Joan Rivers Death Latest News: Melissa Rivers Slams Medical Malpractice, Mother Death '100% Preventable'

Eight months after the death of her mother Joan Rivers at the age of 81, Melissa Rivers is now claiming that her death was "100 percent preventable."

Joan died following complications from an endoscopic procedure performed at Yorkville Endoscopy Clinic in Manhattan, New York.

Melissa has filed a lawsuit against the clinic which she believes should have paid more "attention to the vital signs."

Interviewed in the Today show on Monday, Melissa said she found out via email that her mother was already in a medically induced coma while she was flying out to be by her side.

Melissa alleged that the doctors performed procedures on Joan without her mother's written consent while she was sedated and continued to operate on her even while her vital signs were waning with her blood pressure and heart rate dropping. Some of the doctors involved also allegedly did not have the credentials and privileges to treat patients at the facility.

"Not only did my mother deserve better; every patient deserves better. It is my goal to make sure that this kind of horrific medical treatment never happens to anyone again," Melissa said.

Joan went to the medical center for a procedure to evaluate her "voice changes" and to determine what was causing her stomach reflux, according to a New York medical examiner.

The lawsuit acknowledged that Joan Rivers signed an authorization and gave her consent to let the doctors perform on her an upper endoscopy, or EGD, with possible biopsy/possible polypectomy and possible dilation of the esophagus. It was unclear if Rivers had given verbal consent to any other procedures before being sedated. The lawsuit maintained she did not.

Before the procedures for which Joan consented, she first underwent a laryngoscopy. This was a procedure she did not consent to in writing, the lawsuit stated. It was during this procedure that the doctors had "difficulty maintaining" her oxygen saturation at an "appropriate and safe level to ensure her airway was not compromised."

The doctors then did the EGD, which Joan consented to do. A second laryngoscopy was then performed. It was during this procedure, which Joan never consented to, that she suffered from laryngospasm, a spasm of the vocal cords that makes it difficult to breathe, according to the investigation.

Her body was unable to take in enough oxygen and eventually her heart stopped delivering fresh oxygenated blood to her brain, which shut down. According to the medical examiner's office, the cause of death was "anoxic encephalopathy due to hypoxic arrest," a medical description of brain damage caused by lack of oxygen "that happened during the laryngoscopy."

When the doctors finally noticed that Joan's vital signs had dropped, they tried to get her to breathe better. The lawsuit alleged that they should have done an emergency tracheotomy. It was at this point that the doctor most equipped and able to perform the said procedure had left the room.

According to the lawsuit, Dr. Gwen Korovin, who performed the second laryngoscopy, was a licensed medical doctor, who "did not have privileges to perform surgical procedures" at Yorkville Endoscopy nor was she credentialed to perform procedures at the facility.

The lawsuit further alleged that Korovin left the room when Joan's situation deteriorated "because she knew she was not permitted to perform medical services and procedures" at that particular clinic and wanted to "avoid getting caught."

Korovin's lawyers maintained that their client "is respected and admired by her peers in the medical community and she is revered by her patients."

The Yorkville Endoscopy Clinic has released a statement saying that all its doctors are "certified for advance cardiac life support" and that "anaesthesiologists monitor their patients utilizing state-of-the-art monitoring equipment all throughout the procedure up to recovery."

"Filing this lawsuit was one of the most difficult decisions I've ever had to make," Melissa said. "What ultimately guided me was my unwavering belief that no family should ever have to go through what my mother, Cooper and I have been through. The level of medical mismanagement, incompetency, disrespect and outrageous behavior is shocking and, frankly, almost incomprehensible."