Surgeons in Boston have performed the first penile transplant in the United States, a procedure that soon could help severely wounded soldiers, surgeons at Massachusetts General Hospitalsaid Monday.

Thomas Manning, 64, whose penis was removed in 2012 due to penile cancer, is recovering well and showing no signs of rejecting the transplant, his surgeons said.

“Today I begin a new chapter filled with personal hope and hope for others who have suffered genital injuries, particularly for our servicemembers who put their lives on the line and suffer serious damage as a result,” Manning said in a statement.

Manning, a bank courier in Halifax, Mass., underwent the operation on May 8 and 9. The surgeons who led the 15-hour procedure, Curtis Cetrulo and Dickens Ko, said they were "cautiously optimistic" Manning will regain full urinary and sexual function.

"He's doing well so far," Cetrulo said at a news conference Monday. "He is up and out of bed. Emotionally he's doing amazingly well. He's a very positive person."

Manning has been cancer free for about four years, the physicians said. He is not married but said the transplant could help make such a relationship possible.

The surgeons stressed the psychological aspects of such transplants.

"He went through rigorous psychological screening," Cetrulo said, adding that Manning "wants to be whole again. He doesn't want to be in the shadows."

Cetrulo said such injuries suffered on the battlefield can leave soldiers isolated and despondent — and contemplating suicide. Transplants, he said, could help.

"We hope to make this kind of experimental surgery safe and routine," Cetrulo said.

More than 3½ years of research and teamwork among dozens of specialists in plastic and reconstructive surgery, urology,  psychiatry, infectious disease, nursing and social work culminated in the transplant, Ko said.

"There is a huge sense of collaboration," Ko said.

Massachusetts General is one of five transplant centers across the nation approved to perform penile transplants.

Cetrulo and Ko began researching the possibility of performing a penis transplant in 2012, shortly after an hospital team led by Cetrulo completed its first hand transplant. Working closely with the New England Organ Bank, both surgeons developed surgical approaches.

Alexandra Glazier, who heads the organ bank, thanked the donor family and said the family was "delighted" to hear the transplant was a success. The donor provided other parts to other transplant patients as well, and saved multiple lives, Glazier said.

“We offer our thoughts as they struggle with their loss — and our humble thank you, deep appreciation and admiration for the humanity they showed,” Glazier said.

A team of South Africa surgeons performed what is believed to be the world's first successful penis transplant in a nine-hour operation in December 2014. Stellenbosch University said last spring that the patient had regained full function in the transplanted organ.