A soldier who lost all four limbs in an Iraq roadside bombing says he looks forward to driving and swimming with his new arms.

Twenty-six-year-old Brendan Marrocco spoke at a news conference Tuesday at Johns Hopkins Hospital in Baltimore. He was joined by the surgeons who performed the double-arm transplant there.

Marrocco says he's happy and amazed to have new arms. He has prosthetic legs but says that without arms, he felt "kind of lost for a while."

"It's given me a lot of hope for the future," Marrocco said. "I feel like it's given me a second chance."

The procedure was only the seventh double-hand or double-arm transplant ever conducted in the United States.

Dr. W. P. Andrew Lee, the lead surgeon on Marrocco's team, said this surgery "was the most extensive and complicated" transplant surgery ever performed, involving the connecting of bone, nerves, blood vessels, muscles, and other tissue. He said his team had rehearsed four times on cadavers in the last two years.

Lee said Marrocco, a New York native, will check out of the hospital Tuesday, and begin outpatient therapy while staying nearby for several months.

The infantryman was injured by a roadside bomb in 2009. The New York City man also received bone marrow from the same dead donor to minimize the medicine needed to prevent rejection.

The military is sponsoring operations like these to help wounded troops. About 300 have lost arms or hands in the wars.

Through all the procedures and the recovery, Marrocco has generally maintained a positive attitude.

In a 2010 interview with CBS News correspondent David Martin, he said: "I just seem to have a good lookout on things. I'm still alive. My buddy wasn't as fortunate."

Marrocco was referring to one of the other members of his squad, whom he described as his best friend, who was killed when their Humvee ran over a tripwire.

"I remember the flash, the sound, it was ridiculously loud. I remember all the screaming in the truck trying to see who was hurt. After that I remember waking up in the hospital," Marrocco said.

He described the thing that took his limbs as a "copper dart" that was "molten hot," saying it "cauterized my wounds." The New York native said he has marveled at the fact that he survived, when others did not, adding that his friend who died "wasn't hurt nearly as bad as I was."

Even after waking up in the hospital and realizing that he lost his arms, Marrocco said his father told him his reaction was relatively nonchalant, saying "I just shrugged my shoulders and went back to sleep."