March 6, 2003 -- In the first operation of its kind, doctors used stem cells from a 16-year-old Almont, Mich., boy's own blood to repair his heart after he was accidentally shot in the heart with a nail gun and subsequently suffered a heart attack.
It is hoped that the stem cells will repair and regenerate Dimitri Bonnville's damaged heart and its blood vessels. When the teen was first brought to the hospital after the Feb. 1 construction accident, surgeons immediately removed the three-inch-long nail and repaired the hole in his heart. But it was not apparent until about one day later that he had also suffered a large amount of heart muscle damage.
At that point it was too late to go ahead with traditional heart attack treatments, so doctors at Beaumont Hospital in Royal Oak, Mich., led by Dr. Cindy Grines and Dr. William O'Neill, suggested an experimental treatment that had never been done on any other patient. They would harvest stem cells from Bonnville's own blood, rather than bone marrow, and use those cells to repair his heart.
"He had such a massive heart attack," Grines told Good Morning America in an exclusive interview after the hospital announced the procedure. "It would have left him unable to do many of the things a normal 16-year-old does."
Good News for Late Arrivals
Initially, when doctors tested the boy's heart muscle, they found that it was working at about 25 percent capacity. Five days after the stem cell transplant, the capacity climbed to 35 percent and doctors expect it to continue to improve as the boy recovers at home. They will know more in three months, Grines said.
Similar transplants have been done — mostly in Europe — using stem cells from the patient's bone marrow, with some apparent success. But the Michigan procedure is significant because getting stem cells from blood is simpler and less painful than getting them from bone marrow.
"With a bone marrow transplant, we have to puncture the bone many times and the patient needs anesthesia in an operating room," Grines said. "Plus you don't get pure stem cells from bone marrow."
The doctors say this new treatment could have great promise for those who suffer massive heart attacks and come to the hospital too late for other types of treatment, like angioplasty.
Scary, But Few Options
The experimental procedure seemed like the right choice for an active teenage boy who before the accident enjoyed wrestling, soccer, baseball and snowboarding.
One of the options was to give the boy conventional medication that would have extended his life, but wouldn't have improved his heart function — meaning he couldn't have lived a normal life, doctors said. The other option was a heart transplant down the road, but such procedures are expensive and risky and there are not many donors.
"We felt it was a low-risk, high-gain procedure," said Craig Bonnville, Dimitri's father. "All the most recent tests have been positive."
His family was hesitant about the experimental nature of the procedure, but also thought a transplant would be risky.
"It was scary but we didn't have a lot of options," said Tammara Bonnville, the boy's mother. "We had faith in the doctors and the hospital and got as much information as we could before the procedure."
The stem cell transplant itself, performed on Feb. 17, took less than an hour and was relatively simple, doctors said.
Stepping in for Heart Muscle
"We gave Dimitri medication to stimulate his bone marrow to produce more stem cells, which then went into his bloodstream," Grines said. Four days later, they harvested Dimitri's stem cells with a special blood collection machine. Then, using a heart catheter, they transplanted the stem cells into his left anterior descending artery, which supplies blood to the front of the heart.
Stem cells, which are embryonic in origin, are like chameleons of the body. They can become any cell — including muscle and brain cells — and they have the potential to regenerate tissue. As we grow into adults, we possess fewer and fewer stem cells, and most are in our bone marrow.
After a heart attack, the heart doesn't have the ability to repair itself, so if some of the heart muscle cells die, they won't divide or grow again. Enter the stem cells, which can step in for the heart muscle cells.
"So we thought we could take stem cells, put them in the heart because they have the ability to become heart muscle which would improve the pumping function of the heart, or else become blood vessels to improve blood flow," Grines said.
Five days following the stem cell transplant, a defibrillator was implanted in Dimitri's chest. The device helps control any irregular heartbeats that he is now susceptible to as a result of the damage caused by the heart attack. So far, Bonnville has tolerated the procedure well with no complications.
"I feel pretty good," Dimitri Bonnville said. "I should return to school in a couple weeks. I don't know when I'll be able to play sports again yet."