A car accident took Nick Anderson's leg, and nearly his arm. "We had to fight with them not to take the arm off," his grandfather, Frank Anderson, said Wednesday, recounting the night of the December 2004 accident.

Nick Anderson's left arm no longer has an elbow joint, and two of the three main nerves have been severed, leaving the arm paralyzed and without feeling in places. Doctors at Johns Hopkins Hospital hope a rare nerve implant from mother to son on Thursday will help restore use of the hand.

If the nerve segments are transplanted successfully, doctors will know in three to four months if the graft has taken hold, and in a year to 18 months if use of the arm has been regained, said Dr. Allan Belzberg, who will perform the surgery.

Belzberg had hoped to repair Anderson's arm without a transplant several weeks ago, but found during the surgery that the damage to the 19-year-old's arm was more severe than anticipated. The doctor decided to consider a transplant. The neurosurgeon said he conferred by telephone from the operating room with Dr. Susan McKinnon, who first performed the surgery, before calling Anderson's family.

"It took them about a second to decide, so I closed up," Belzberg said.

Such surgeries are rare, but increasing, and raising hopes of saving limbs that previously would have been lost.

Donations from cadavers are more common. McKinnon, who first performed the first live donor surgery in 1993 at Barnes Jewish Hospital in St. Louis, has since performed seven or eight transplants, with some function restored in most cases, Belzberg said.

Since then, surgeons in Houston also transplanted nerves in 2000 from a mother to her eight-month old son, who had the nerves in his left shoulder torn during birth. In January, a Connecticut man had nerves from his mother implanted at Monmouth Medical Center in New Jersey to help reverse paralysis of his right arm.

In some cases, grafts can be taken from other parts of the body, but in Anderson's case, the loss of his leg meant there wasn't enough donor nerve to use, Belzberg said.

Nick Anderson's mother, Frankie Anderson, 40, had nerve segments removed from each arm and leg on Tuesday.

"I have numb spots," she said, tapping her elbow and revealing nearly foot-long incisions on the inside of each arm.

The numbness will be permanent in small patches on each elbow and the inside of each foot, Belzberg said.

Frankie Anderson said the decision to donate "was made the day of the accident."

"If they had a way of cutting off my arm and putting it on him, I would have done that," she said.

Belzberg said complicating factors include the large amount of nerve that has been lost — a six-inch gap needs to be bridged — and the fact that Anderson had a brain tumor removed two years ago. Belzberg said he had been concerned the anti-rejection drugs needed to allow his body to accept the transplant might affect his ability to fight off a recurrence of the tumor.

"Are we suppressing the ability of the body to resist? We don't think we are, but that's one of my major concerns," Belzberg said.

Anderson will not have to take the anti-rejection drugs permanently because the donated nerves act only as a scaffold, or conduit, on which his own nerve cells will grow. Once they have overgrown the donated nerve cells, the anti-rejection drugs can be stopped and his body will remove the foreign, donated nerve cells, Belzberg said.

Family members say they have been told the surgery has a 50-50 chance of success.

Frank Anderson said he hopes the surgery will help "get the message out that limbs can be saved."