Endovascular Repair of Ruptured Abdominal Aneurysms Yields Better Outcome Than Open Surgery
By Thomas R. Collins
Medscape Medical News
January 20, 2010 (Hollywood, Florida) — Repair of ruptured abdominal aortic aneurysms with a minimally invasive endovascular approach is associated with a greater than 25% reduction in mortality, compared with an open surgery approach, according to the results of a Dutch study reported here at the 22nd Annual International Symposium on Endovascular Therapy.
The same researchers have also found a biomarker that might make it easier to find leaks involved in endovascular repair cases without computed tomography (CT) scanning.
Endovascular treatment with stent grafts has been shown in other studies to be effective in emergency cases of ruptured abdominal aortic aneurysm, but this study is believed to be the first that actually compares results in patients deemed suitable for either open surgical repair or endovascular repair, the Dutch team reported here.
After 6 months, 7 of the 25 patients (28%) treated with the endovascular approach had died, compared with 18 of the 33 patients (55%) treated with open surgical repair in a study performed at Atrium Medical Center in Heerlen, the Netherlands (P?< .05).
"It suggests that emergency EVAR [endovascular aneurysm repair] is the preferred treatment option for patients with an EVAR-suitable ruptured abdominal aneurysm," investigator Jan Ten Bosch, MD, a surgery resident at Atrium, said during the presentation.
Studies have shown that as many as 80% of patients die when their abdominal aortic aneurysms rupture, Dr. Ten Bosch pointed out.
Previous studies evaluating the endovascular approach have had significant selection bias, with only the most ideal patients being chosen, he noted.
"Patients with a favorable anatomy?.?.?. and patients with a better hemodynamic status are recruited for the EVAR group," he said. "The objective of our study was to compare emergency abdominal aneurysm repair in all EVAR-suitable patients?.?.?. who underwent [computed tomography angiography] scanning."
Two separate reviews of the scans were done to determine that the patients were fit for EVAR.
Patients who were deemed eligible for EVAR were "pseudorandomized," he said; the endovascular approach was used only when the endovascular surgeon was on-call and available to do the procedure. When that surgeon wasn't available, open surgery was performed.
The endovascular patients had an average hospital stay of 8 days, whereas the open surgery patients had an average stay of 18 days.
A problem with endovascular repair of abdominal aortic aneurysms is that 1 in 10 develops leaks, and the leaks traditionally have been found only with expensive CT angiography scans performed during follow-up.
The Atrium team found a possible biomarker that can identify the leaks without such scanning. The presence of matrix metalloproteinase-9 (MMP-9) was shown to be a predictor of aortic leaks.
In a study of 37 patients, all 17 with a leak had significantly higher MMP-9 levels, whereas only 1 who did not have a leak had higher MMP-9 levels.
That could mean that, eventually, a simple blood test might be all that is needed to determine whether there is leakage, Dr. Ten Bosch explained. He said that Atrium researchers hope to start a prospective multicenter trial to test the predictive value of MMP-9.
Constantino Pena, MD, an interventional radiologist at the Baptist Cardiac Vascular Institute in Miami, Florida, who moderated the session, said the studies were impressive.
"He hits on 2 very important topics in terms of endovascular repair," Dr. Pena told Medscape Radiology.
He said that with more study, the use of MMP-9 could be a major breakthrough. "I think we all want to reduce the radiation surveillance of these patients," he added.
The studies did not receive commercial support. Dr. Ten Bosch and Dr. Pena have disclosed no relevant financial relationships.
22nd Annual International Symposium on Endovascular Therapy (ISET): Abstracts?45 and 100. Presented January?18, 2010.
