Appendix Abdominal Aortic Aneurysms

Associated Press - September 12, 2006

WASHINGTON - Edward Mooney had a weak spot on his largest blood vessel that he knew too well could burst and kill him almost instantly: That's how both his parents died. His doctor offered an experimental fix, using tiny corkscrew-shaped staples to patch the artery.

If the fix holds—─and Mooney is only the first U.S. patient of 25 slated to test it—─the tiny staple could help usher in a next generation of patches to repair this sneaky killer.

"It gives the surgeon control again," says Dr. David Deaton of Georgetown University Hospital, who is leading the study.

At issue is a balloon-like bulge in the wall of the aorta, the blood vessel that runs like a river from the heart to the groin, with tributaries that branch off to carry blood around the body.

Those weak spots are fairly common where the aorta passes through the abdomen, especially in older people. Doctors diagnose about 200,000 abdominal aortic aneurysms, or "AAAs," each year, but suspect tens of thousands more people silently harbor one.

The pressure of pounding blood can burst open those aneurysms. AAAs kill 15,000 Americans annually.

For years, doctors could only replace the aorta's weak spot by sewing on a tough tubing, an arduous operation that required two months of recuperation.

But since 1999, doctors have repaired more and more AAAs with a far less invasive method: They thread a patch through a small incision up to the weak spot and wedge it into place. The patches are almost like a long sleeve, walling off the bulge with half the side effects and recovery time of open surgery.

Thousands of patients get those patches today with good results. But they're not perfect. They don't fit all aortas properly, meaning everyone's not a candidate.

Nor do doctors know how long they'll last compared to open surgery; studies are under way to try to tell. The Food and Drug Administration began issuing safety warnings in 2001 about deaths linked to patches that leaked or moved out of place, and by 2003 one troublesome model had been pulled off the market. And while the risks are small, recipients of all brands of so-called endovascular patches are supposed to get regular checks to make sure they're not working loose.

"We believe they work," stresses Dr. Irving Kron, the University of Virginia's surgery chairman and a spokesman for the American Heart Association.

But the questions mean that surgeons often reserve the patches for AAA patients who, because of age or other disease, aren't likely to live for many years. For a younger patient who doesn't have a textbook aneurysm, "why take the chance of having to redo something?" Kron says.

Yet just because younger patients can tolerate grueling surgery doesn't mean they should have to, says Deaton, a pioneer of less invasive patching. Hence the hunt for a next-generation patch - and that's where the tiny stapler comes in.

Deaton compares it to combining the best of open surgery and patching. He threads a patch up an artery in the groin to the AAA. Then he threads in the tiny staple, made by Aptus Endosystems. Instead of wedging the patch into place, he staples it into what he deems the healthiest remaining sections of the aorta.

"It goes all the way into the tissue," explains Deaton, saying that means it should be as stable long term as the sutures used during open surgery.

Deaton and a colleague from New York's Montefiore Medical Center traveled to Venezuela last year to perform the first AAA repairs using the tiny staple; the two patients are reported to be faring well.

The new U.S. trial will enroll patients at Georgetown in the nation's capital, as well as Emory University in Atlanta and the University of Pennsylvania. "Time will tell," cautioned the heart association's Kron, if the stapler really will make a difference.

Mooney, 70, said Deaton offered to repair his AAA with today's standard patches, but that the idea of a possibly more precise fit made him volunteer for the experiment.

"I'm delighted this is repaired, because you're living with a time bomb," said Mooney, who feels fine two months later.