Study finds advantages over conventional operation
WEDNESDAY, Jan. 30 (HealthDay News) -- An operation using tiny incisions to repair a potentially fatal weakness of a major heart artery has a lower death rate and better overall results than conventional surgery, according to a major new study.
"There have been a couple of randomized trials in Europe, both of which showed perioperative benefits with EVAR [endovascular aneurysm repair]," said study author Dr. Marc L. Schermerhorn, an assistant professor of surgery at Beth Israel Deaconess Medical Center in Boston. "In terms of early results, our study certainly confirmed the results of the randomized trials. We prove that those results are transferable to the U.S. Medicare population."
"Perioperative" refers to the period immediately after a procedure to repair a bulge in the abdominal aorta, the body's largest heart vessel. With conventional surgery, the weak spot is patched through a large incision in the abdomen. With endovascular repair, the weak spot is strengthened by a patch or tube threaded upward from small incisions in the groin.
The new study compiled results of 22,830 such procedures, half conventional surgery, half EVAR, in Medicare recipients. As did the earlier studies, it showed a marked difference in death rates immediately after the procedure, with the difference widening with age. For example, just 0.4 percent of people aged 67 to 69 having EVAR died following the procedure, compared to 2.5 percent of those having conventional surgery. The comparable rates for people aged 85 and older were 2.7 percent for those having EVAR, and 11.2 percent for those having conventional surgery.
The difference in death rates narrowed in the year that followed the procedures, disappearing in the fourth year after the procedure.
EVAR offers other immediate advantages, such as a shorter hospital stay -- an average of three days versus nine days for conventional surgery. And 95 percent of those having EVAR went home from the hospital rather than to a rehabilitation facility or nursing home, compared to 80 percent of people having conventional surgery, Schermerhorn said.
"If the anatomy is good, EVAR is worth considering for any age group," Schermerhorn said. The length of the aorta beneath the arteries to the kidneys must be long enough to allow the procedure, he added.
Dr. Roy Greenberg, director of endovascular research at the Cleveland Clinic, said the new study confirms "what other trials have already shown us."
However, the new study has some shortcomings that partially offset the advantage offered by such a large database, Greenberg said. The major disadvantage is that it lumps together a very diverse group of cases, "comparing patients that are not easily comparable," he explained.
"We do an intervention in these cases not because the aneurysm is bothering patients but because we believe it will prolong patients' lives," he said. "The real question is, are we prolonging patients' lives, and we can't get an answer from this data set. There are too many compounding factors."
Still, the new report "does point out the pros and cons that are very important when we talk to patients about a procedure," Greenberg said.
Dr. Joseph Coselli, chief of adult cardiac surgery at the Texas Heart Institute, concurred that the new research confirms the short-term benefits of EVAR, at least for older patients.
"The mortality rate is lower, morbidity is clearly lower and hospitalization time, blood requirements and the ability to return home or to work are certainly less than with open surgery," he said.
But some issues haven't been completely resolved, Coselli said. "Durability of EVAR is still up in the air," he said. "And there still is a group of patients on the younger end that may yet, based on current technology, require an open operation."
Learn about abdominal aortic aneurysms and their treatment from the U.S. National Library of Medicine.
SOURCES: Marc L. Schermerhorn, M.D., assistant professor, surgery, Beth Israel Deaconess Medical Center, Boston; Roy Greenberg, M.D., director, endovascular research, Cleveland Clinic; Joseph Coselli, M.D., chief, adult cardiac surgery, Texas Heart Institute, Houston; Jan. 31, 2008, New England Journal of Medicine
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