BALTIMORE (CBS News) -- The most amazing story we saw Tuesday involves a courageous young U.S. Army sergeant severely wounded in Iraq and the incredible surgery that gave him arms back.
Not prosthetic arms, but two real human arms.
The operation on 26-year-old Sgt. Brendan Marrocco of New York was performed in December. On Monday, we got our first look at the results. When Marrocco moved his arms, he made medical history.
"I feel like I got a second chance to start over after I got hurt," he said at a news conference.
He was gesturing with transplanted arms -- real arms from an anonymous donor who died.
"It feels amazing. It's something I was waiting for, for a long time," Marrocco said. "Now that it finally happened, I really don't know what to say because it's such a big thing for my life, just fantastic."
Amazing and fantastic because Marrocco was the first quadruple amputee from America's wars to survive -- just barely, as he told us the first time we met him nearly three years ago.
"I died three times and came back ... flat out dead," he told CBS News in 2010.
His vehicle had been hit in Iraq in 2009 by an Iranian-made roadside bomb, which severed his carotid artery and tore off all four of his limbs.
Marrocco said the lack of arms is a lot more difficult than the lack of legs.
"Without legs you can still be independent, you know. Without arms there's so much more that you can't do," he said.
A team of 16 surgeons led by Dr. Andrew Lee at Johns Hopkins University Hospital in Baltimore performed the 13-hour surgery last month. Before that, there had been only six successful double hand transplants, and never anything like this.
"We knew arm transplants can help people, but we didn't know whether we could transplant so high up in the arm," Lee said.
He will have to go through years of physical therapy, which meant the decision to do the transplant was as much psychological as medical.
"With our experience, and with the determination and stamina that Brendan Marrocco has demonstrated, we had no doubt that this was the right thing to do for him," Lee said. His doctors predicted Marrocco will be using his hands for just about everything.
"I never really accepted the fact that I didn't have arms, so now that I have them again, it's almost like it never happened. It's like I went back four years and I'm me again," he said.
Marrocco was discharged from the hospital Tuesday. No one will be watching his recovery more closely than four other servicemen who have since joined him as survivors of quadruple amputations.
CBS medical correspondent Dr. Jon LaPook explained while the transplant process is complicated, it's not impossible. The first step was to connect the bones using plates and screws. Then the muscles and tendons were connected, and then the blood vessels -- arteries and veins. They are crucial in bringing nourishment to the arm, LaPook explained.
The nerves from Marrocco's body will slowly grow down the transplanted arm at a rate of about one inch a month, LaPook said. It will be many months, and even years, with intensive physical therapy before he gets back whatever function he's going to eventually regain.
In order to prevent the body from rejecting the new transplants, doctors took bone marrow cells from the arm donor's spine and gave them to Brendan. Those cells trick his immune system into thinking these new arms are his own, and allows doctors to use online one anti-rejection drug instead of the usual three. This strategy has only been used in five other patients.