Jan 30, 2004
A new technique for repairing aneurysms in the largest artery of the body has a better survival rate and a speedier recovery time than traditional open surgery to repair the weak blood vessel, researchers from NewYork-Presbyterian Hospital report in this month's issue of the Journal of Vascular Surgery.
This is the first broad-scale look at the use of this minimally invasive procedure, known as endovascular repair, said Dr. K. Craig Kent, chief of the division of vascular surgery at NewYork-Presbyterian Hospital and professor of surgery at Weill Cornell Medical College and Columbia University College of Physicians Surgeons. We found that the outcomes were excellent and much better than we anticipated.
About 15,000 people in the U.S. die each year after rupture of an aortic aneurysm, a weak spot that balloons outward and fills with blood.
Endovascular repair became widely available in 1999 and has skyrocketed in popularity. Dr. Kent and his colleagues at Columbia University's International Center for Health Outcomes and Innovation Research (InCHOIR) found that the procedure at least in New York State is now performed more often than traditional open surgery to fix the potentially life-threatening weak spots in the aorta, the artery that supplies most of the blood in the body.
The researchers analyzed New York State hospital discharge data between 1995 and 2002, using information gathered by SPARCS, or the Statewide Planning and Research Cooperative System. They expected that the new technique would actually be riskier for patients, as doctors started using the newly-available devices.
Instead, they found that in 2002, 4.2% of patients undergoing open surgery died in the hospital compared with only 0.8% undergoing endovascular repair, even though the minimally invasive technique was used more often in older and sicker patients.
For patients it's just a dramatically different way to be treated, said Dr. Kent. Our study found that patients who have the minimally invasive procedure spend anywhere from one to three days in the hospital and most leave after one day. People who have the traditional surgery spend anywhere from five to 11 days in the hospital, but it's usually a seven to eight day stay.
After endovascular repair, patients are back to their normal activities after two weeks, compared with six weeks to two months for those undergoing traditional open surgery, Dr. Kent said.
During traditional surgery, the abdomen is opened surgically, and a plastic tube is sewn into the blood vessel to bypass the weakened portion. With endovascular repair, a catheter is inserted into a blood vessel in the upper thigh and snaked upwards into the abdominal aorta. A similar plastic tube is delivered to the spot and used to bypass the weak portion, but the tube is held in place by a stent a mesh-like device that expands and presses the tube against artery walls.
Four endostents or endografts are now available in the U.S. that can be used to repair abdominal aortic aneurysms. The first was approved by the FDA in 1999.
The new devices do have some drawbacks, Dr. Kent said. They can slip, which allows blood to leak back into the aneurysm. Therefore, patients who undergo endovascular repair need periodic monitoring by CAT scan, and are more likely than surgery patients to need another procedure to fix problems.
Probably 80% to 85% will be OK, but about 10% to 15% will require another intervention because the stent has shifted and blood is making its way back into the aneurysm, said Dr. Kent. The vast majority of time, those reinterventions can be fairly straightforward, not major surgery. However, there is always a possibility that major surgery will still be necessary although the chances of that happening are extraordinarily small, less than one percent.
The new devices also allow more patients particularly those whose age or other medical conditions make surgery risky to have their aneurysms repaired. The researchers found a 20% increase in repairs of all abdominal aortic aneurysms in New York State after 2000, compared with the years before.
Before endografts came along, some patients just didn't get the surgery because they couldn't tolerate a major operation, and they most likely died of their aneurysm, said Dr. Kent. Now that endostents are available, many of those patients are getting stents with much less risk and, in fact, are living longer.
Open surgery is still the standard of care for relatively healthy people in their 50s or 60s who have an aneurysm in their aorta.
Traditional surgery is still here for aneurysm repair; it hasn't gone away nor should it go away, said Dr. Kent. Older patients those in their 70s or 80s, who may have other medical problems are better candidates for an endostent, he said.
However, some younger patients demand the less invasive technique, he said. We do have a problem with some of the younger patients now. I truly believe that someone in their 50s or very early 60s who is otherwise healthy should have open repair, he said. However, I have put endografts in people in their 50s and 60s because they wouldn't have it any other way. The patient appeal of this is quite dramatic.
The study found that the number of hospitals in New York State performing endovascular repair increased from 24 to 60 between 2000 and 2002. In 2002, endovascular repair was actually performed more often than open surgery (871 vs. 783).
More data will hopefully confirm these initial findings, said study co-author Dr. Peter Faries, chief of endovascular surgery at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. The study could not determine the number of patients that needed a reintervention, and could not determine if the survival rates were better at some hospitals compared with others.
In addition to Drs. Kent and Faries, the study's co-authors include Dr. Patrice Anderson (lead author; postdoctoral research fellow in the department of surgery at Columbia University College of Physicians Surgeons); Dr. Raymond Arons (assistant professor in sociomedical science at Columbia University Mailman School of Public Health; assistant professor of nursing, Columbia University School of Nursing); Dr. Alan Moskowitz (associate professor of clinical medicine, division of general medicine, Columbia University College of Physicians Surgeons; associate professor of clinical health policy and management, Columbia University Mailman School of Public Health); Dr. Annetine Gelijns (associate professor of surgery, Columbia University College of Physicians Surgeons; associate professor of health policy and management, Columbia University Mailman School of Public Health); Dr. Corey Magnell (postdoctoral research fellow in the department of surgery, Columbia University College of Physicians Surgeons); Dr. Dan Clair (assistant professor of surgery, Columbia University College of Physicians Surgeons); and Dr. Roman Nowygrod (professor of surgery, Columbia University College of Physicians Surgeons).
The study was funded through Columbia University College of Physicians Surgeons, Mailman School of Public Health, and Weill Cornell Medical College. Drs. Anderson and Magnell were partially funded by the National Institutes of Health under a National Research Service Award (NRSA) in Cardiovascular Surgery.