I can’t reveal much about the anonymous young man who this year became the world’s first recipient of a transplanted penis and scrotum. All I can say is he’s American and a soldier who stepped on an improvised explosive device in Afghanistan in 2010. His legs were blown off as well as his genitals and abdomen. It was a devastating injury.

But he recovered well and learned to walk again with prosthetic limbs. He’s very mobile and regained a huge amount of independence. Outwardly, you might not know he was different from other men his age; but for eight years he found it hard to have a relationship and was unable to have sex. Despite this, he has an excellent mental attitude, which is what made him an ideal candidate for such pioneering surgery. We had many conversations about the benefits and risks, such as the operation failing or the penis not working. There was never any doubt in his mind: having a penis again was his priority.

I met him in 2013. Nearly 1,400 men in the US military returned from Iraq and Afghanistan with injuries to their genitals and urinary tracts between 2001 and 2013, more than a third of them severely. These guys are young and physically fit, so to lose their genitals is particularly devastating. This man didn’t have the donor sites – places we’d normally take skin from, including his legs – we’d normally use for genital reconstruction. Our team, at Johns Hopkins hospital in Baltimore, spent five years working out how to supply blood to a transplant of this size and complexity. We also practised extensively on cadavers.

It was tough to find a donor, too. People aren’t aware that you can donate your genitals. It’s not like a kidney or liver; even face transplants are more common. We were able to tell the donor family that the recipient was a veteran with a devastating pelvic injury. They had links to the military, so were willing to go ahead.

There have been three other penis transplants but this is the first to include the scrotum. There are ethical considerations, obviously: if we had included the testes, the recipient could have fathered a child with the donor’s DNA. This young man doesn’t have children, but was happy with the decision. He’s not in a relationship, but I’m sure he’s thinking about getting into one now.

The surgery took place on 26 March this year and lasted 14 hours. It went perfectly. I was one of 11 surgeons. I’m a paediatric plastic surgeon, and one of my specialties is genital reconstruction. With a team that big, you can rotate. You don’t think about eating or drinking because of the adrenaline. You’re so engrossed and invested in the operation.

When I do routine surgery, I listen to music, but something like this requires silence and precision focus. No distractions. What made this complicated is the different blood supplies to the scrotum, penis and abdominal wall. You have to hook up very small blood vessels. That’s what takes the time: stitching together blood vessel after blood vessel. Their internal diameter is 1-2mm, so you use a high-powered microscope, stitches the thickness of a human hair and needles 2-3mm long. It’s very complex.

This is life-enhancing, rather than life-saving surgery. It’s not more of a challenge than attaching an arm, but the function of the penis is multi-faceted: we had to think about the nerves that create sensation, the blood vessels that mean he’ll be able to get an erection, attaching the urethra to allow him to urinate, putting the scrotum where it needs to go. He’ll always have the very serious risk of the body rejecting the organ, plus a higher risk of cancers and opportunistic infections. But we also performed a bone marrow transplant from the donor to help him accept the organ and minimise those risks.

Eight months on, he’s recovering well. With every organ donation, you have to match blood type and look at what viruses the donor was exposed to; but with this we had to think about age and skin tone, too. We also took size into consideration. You want something that’s at least average – an organ that’s healthy, and from a young person. You don’t want to transplant a penis with erectile dysfunction or an aesthetic problem.

The patient is happy with the result. We’re monitoring return of sensation and whether or not he’s rejecting the organ, but right now, his body is accepting it, and it looks great. He has been able to have an erection. In the future, he shouldn’t have any issues. He’s young and medicine is advancing so quickly that we’re hopeful he may be able to get off immunosuppressants in the next five to 10 years.

Even without the transplant, I believe this patient would’ve been OK; he’s got a great life plan. But to have a functional penis again has significantly enhanced his life. It’s brought him much happiness.

• As told to Sophie Haydock

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