This article originally appeared in the Winter 2017 issue of Tufts Medicine.

Seldom has a sensitive medical procedure been more openly discussed. Thomas Manning, the 64-year-old transplant recipient who had had his penis amputated after being diagnosed with penile cancer, was an unusually candid patient, chatting freely with reporters about his hopes and fears and urging other men to follow his public example. “Don’t hide behind a rock,” he told them.

Cetrulo, 46, came to this operation well prepared. In 2012 he had performed a hand transplant at MGH, the hospital’s first. He also runs a transplantation research laboratory directed at finding ways to eliminate the need for antirejection drugs required for transplantation. He spoke with Tufts Medicine about his latest path-breaking surgery.

Where did the idea of a penis transplant begin?

I was giving a lecture on the hand transplant when one of the urologists in the audience came up to me and said, “We have all these desperate patients. Can we transplant penile tissue?” That was a few years ago, and we started working on it. Incidentally, the Department of Defense has also been working on this vigorously, too, because of so many wounded warriors coming back from Iraq and Afghanistan who have devastating injuries and a really high suicide rate—as high as 25 to 50 percent.

What medical advances made this surgery possible?

One advance would be the technical ability to attach very small tendons and nerves together using a microscope. The second would be the immunosuppressive drugs we have now, where the side effects have gotten more manageable.

To what degree is your work therapeutic by nature?

I would say more than I anticipated. With Joe, who was our patient in the hand-transplant case, I was amazed by all the pictures he would send me after the surgery of him doing things in his daily life that meant a lot to him and were incredibly therapeutic—for example, washing his car for the first time in 11 years, or eating chips and dip.

Is there any limit to what transplant surgery can achieve?

Right now the biggest limit on these kinds of procedures is the need for immunosuppression. We have a protocol here at MGH that’s directed at engineering immunologic tolerance so that a patient will not need to take these drugs that can cause kidney failure and certain cancers down the road. We’re very close to achieving that.

We have an approach that we use to “fool” the body. Consider a hand transplant. You take immune cells in the form of blood stem cells from the donor and give them to the recipient, where they take up residence in the recipient’s blood and form, in effect, a second immune system. The recipient becomes a hybrid, having a hybrid immune system of both recipient and donor. Then when we transplant a hand, for example, the recipient’s newer immune system “recognizes” that hand as part of itself and won’t reject it.

Once that research evolves, hypothetically all bets are off when it comes to body part transplantation—is that right?

All bets are on, I would say.