The team of surgeons rehearsed the procedure on cadaver arms four times over the past 18 months, said lead surgeon Dr. W.P. Andrew Lee, director of the Department of Plastic and Reconstructive Surgery at Johns Hopkins.

“On his right side we did an above-elbow transplant by connecting the bone, muscles, blood vessels, nerves and skin between the donor and recipient,” Lee said. On Marrocco’s left side, “in order to preserve the elbow joint, we transplanted the entire donor forearm muscles over his remaining tissues, then rerouted the nerves to the new muscle.”

While Marrocco is doing well, his recovery will be long and risky, the doctor said. “The nerves regenerate at the maximum speed of 1 inch per month. The therapy will continue for a few years, first at Johns Hopkins, then at Walter Reed. The progress will be slow, but the outcome rewarding.”