"The maximum speed is an inch a month for nerve regeneration," he explained. "We're easily looking at a couple years" until the full extent of recovery is known.
While at Pittsburgh, Lee pioneered the novel immune suppression approach used for Marrocco. The surgeon led hand transplant operations on five patients, giving them marrow from their donors in addition to the new limbs. All five recipients have done well and four have been able to take just one anti-rejection drug instead of combination treatments most transplant patients receive.
Minimizing anti-rejection drugs is important because they have side effects and raise the risk of cancer over the long term. Those risks have limited the willingness of surgeons and patients to do more hand, arm and even face transplants. Unlike a life-saving heart or liver transplant, limb transplants are aimed at improving quality of life, not extending it.
Quality of life is a key concern for people missing arms and hands - prosthetics for those limbs are not as advanced as those for feet and legs.
Lee has received funding for his work from AFIRM, the Armed Forces Institute of Regenerative Medicine, a cooperative research network of top hospitals and universities around the country that the government formed about five years ago. With government money, he and several other plastic surgeons around the country are preparing to do more face transplants, possibly using the new minimal immune suppression approach.
Marrocco expects to spend three to four months at Hopkins and then return to a military hospital to continue physical therapy, his father said. Before the operation, he had been living with his older brother in a handicapped-accessible home on New York's Staten Island built with the help of several charities.
The home was heavily damaged by Superstorm Sandy last fall.
Despite being in a lot of pain for some time after the operation, Marrocco showed a sense of humor, his father said. He had a hoarse voice from a tube in his throat during the long surgery, decided that he sounded like Al Pacino, and started doing movie lines.
"He was making the nurses laugh," Alex Marrocco said.