Carmen Blandin Tarleton, whose face was disfigured in an attack by her ex-husband, has become only the second person in the world to undergo the procedure for a second time, after her first transplant began to fail six years after the operation.

She began experiencing scarring, tightness and pain because of a loss of blood flow to her face. Black patches appeared on her face. Her eyelids contracted and her lips began disappearing, making it difficult to eat. She was mostly housebound and resumed taking strong pain medications.

The transplant from an anonymous donor took place at Boston's Brigham and Women's Hospital in July.

"I'm elated," the 52 year old former nurse said after the operation.

"The pain I had is gone," she said. "It's a new chapter in my life. I've been waiting for almost a year. I'm really happy. It's what I needed. I got a great match."

More than 40 patients worldwide have received face transplants, including 16 in the United States.

In 2018, a French man whose immune system rejected his donor face eight years after his first transplant underwent a second.

Dr. Bohdan Pomahac, who did Tarleton's first face transplant, was hesitant to do another and favoured doing reconstruction surgery instead. But his team became convinced of the merits of a second transplant after Tarleton described how much the first one improved her life.

"A team of 45 doctors were involved in the 20-hour, second surgery.

Unlike her first transplant, the donor this time around was considered a much better tissue match.

"This face looks very different than my first one and I can appreciate that. It's a different person," she said, adding the new face allows her to "fit in a little better, and not get stared at so easily."

Australian Associated Press