"Should problems arise with one transplant or the other, as they often do in this type of surgery, one operation can compromise the other ... or more significantly can synergistically affect the overall morbidity/mortality of the patient," he said.
Nash was attacked in February 2009 when her friend and boss, Sandra Herold, asked for help luring Travis, a 200-pond chimp, back into the room-sized cage she kept in her suburban Connecticut home.
Nash lost most of both hands, but had a thumb surgically replaced on her left hand. Doctors removed her eyes and grafted a piece of her leg where her nose used to be.
She has a small slit where her mouth once was. Through it, she takes all her meals by straw.
"She's doing a little bit better," said Monaco. "She still has challenges and still must take food by liquid or pureed. She is at a stage where she is stable, but still has physical issues."
"I'm not a candidate for a hand transplant because I have no eyesight. I hope somewhere along the way to get a face transplant and get a hand transplant at the same time," Nash told Winfrey in her one interview since the attack.