The Wall Street Journal-20080131-Study Is Likely to Bolster Stent-Graft Use

Return to: The_Wall_Street_Journal-20080131

Study Is Likely to Bolster Stent-Graft Use

Full Text (645  words)

New research analyzing more than 22,000 U.S. cases of aortic aneurysm repair is likely to hasten the trend toward more procedures being done with a device called a stent-graft instead of the typical surgery that requires up to eight weeks of recovery.

The study by doctors at Harvard Medical School and the federal Centers for Medicare and Medicaid Services found the death rate in surgery, 4.8%, was four times that of the 1.2% death rate in placing stent-grafts to seal off the aneurysm. Surgery tended to provide a more permanent fix, however, making the findings complex.

Abdominal aortic aneurysms are a potentially lethal bulge in the aorta, the main artery carrying blood from the heart. When the aneurysm balloons out far enough, pressure can cause the aneurysm to burst. Surgical repair, in which the abdomen is opened up and the pressure alleviated with a plastic or fabric tube directly sewn into the aorta wall, is a fix that has been accepted for decades.

Since the mid-1990s, the fabric-and-metal stent-graft has become increasingly popular, largely because this process is easier on the patient. In such "endovascular" procedures within the arteries, the device is slid up through a small incision into an artery in the leg and then into place in the aorta. The tubelike device is designed to seal off the area of the aneurysm and reduce pressure.

Patients tend to prefer the stent-graft process, because recovery typically takes a couple of weeks. There have been questions: How permanent are stent-grafts, and can ruptures and deaths occur even with them in place? How often will they slide out of position or otherwise require new procedures to fix problems? And what are the side effects with both approaches? This study, published in this week's New England Journal of Medicine, provides complex answers that seem to favor the stent-graft in many doctors' minds.

"I think endovascular repair is superior," said William H. Pearce, chief of vascular surgery at Chicago's Northwestern Memorial Hospital, who had read the study. This debate -- surgery versus endovascular procedures -- is playing out throughout medicine. Examples are with heart surgery and coronary stents, and in surgery or stents in carotid arteries in the neck to prevent strokes.

Several top doctors point out that patients are generally better off going to large academic medical centers, where the death rate from surgery generally is from 1% to 2%. The 4.8% rate in the study is more common at smaller community hospitals, they said.

Over time, the study showed there are drawbacks with the stent- graft, despite its short-term advantages. Potentially lethal ruptures were more common among stent-graft patients (1.8% versus 0.5%) after four years. The study looked at 22,830 Medicare patients who underwent aneurysm repair in 2001 to 2004 and followed them into 2005. It isn't known yet what happened beyond four years. There were also more "reinterventions" -- going back in to fix a problem -- with stent- grafts (9% versus 1.7%), but the authors said most were minor.

The study did turn up another finding that favors stent-grafts. The rate of later abdominal operations, for things such as abdominal-wall hernias and bowel obstructions, was much higher in the surgery group (9.7% versus 4.1%).

"They found that open repair isn't always forever," said K. Craig Kent, New York-Presbyterian Hospital's chief of vascular surgery. "The late complication rate is real, and that complication rate is higher than we had thought."

"Surgical repair, even though it's a very good operation, has this instance of incisional hernias and bowel obstruction that somewhat tarnishes it," said vascular surgeon Robert M. Zwolak of Dartmouth Medical School, who had read the study.

The study showed the difference in death rates from surgery compared with stent-grafts increased with the patients' age. Dr. Zwolak said he especially is inclined to use stent-grafts in relatively older patients, from 75 to 84 years old.