Appendix Abdominal Aortic Aneurysms
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?"
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
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