Bethesda, MD – Marine Lance Cpl. Jeffrey Cole was serving his first mission in Afghanistan back in 2010 when he was caught in enemy fire alongside a few members of his unit. When the other troops were gunned down, Cole was able to hold back fire using another Marine’s M204B medium machine gun.

During the fight, Cole was hit in the bicep and tricep in his left arm but continued to return fire as he moved his five comrades to safety. He was given the high Marine honor of the Silver Star for his efforts that day, but he soon learned that the bullets had ripped apart his ulnar nerve, and he would lose all function of his arm.

While emergency room visits total about 110 million annually in the United States, this Marine wasn’t so lucky when he was injured. Cole had to be flown home to the Walter Reed Military Medical Center to receive treatment on his arm, however, it wasn’t normal amputation the doctors had in mind.

Instead, Cole would be one of the first patients in the world to get an unusually long nerve graft implanted into his arm so he could regain function. Grown by cadaver tissue in a lab, this graft was nearly three inches long and was meant to mimic what was left of Cole’s nerve.

Known as an Avance graft, this nerve tissue will connect and repair severed nerves until it eventually revascularizes and becomes a part of the patient’s own tissue. The doctors who performed on Cole had only used tissue grafts between one to two inches long, so using a graft this length was new for everyone involved.

According to Dr. Ian Valerio, the head doctor on Cole’s reconstruction, the average nerve grows about 1mm every day. So this three-inch piece is meant to bridge the gap between broken nerves without causing pain or any extra tension to the patient.

Once the graft revascularized, it would sprout through Cole’s muscles all the way from his bicep to his hand. In order to function properly, Cole was regulated to physical and occupational therapy for six to eight hours a day for two years. And while the average American loses eight days of work due to an occupational injury, unfortunately, Cole wasn’t so lucky. Three years after the accident, at the age of 23, Cole retired from the Marines because even with rehab, his injuries were too severe to serve in combat.

Since the surgery, Cole has regained the majority of his strength and only has lost some dexterity strength. “I can do almost anything a regular person would be able to do,” he explained to Military.com. [He went from ]”no feeling, no movement” from his shoulder down — “it just hung there. But now it’s a complete 180 from where I started.”

Cole’s groundbreaking surgery has served as a model for hundreds of similar surgeries since 2010, all completed at Walter Reed.