New report evaluates rate of reinterventions, readmissions after initial AAA surgery

Dec 30 2010

A new report published in the January issue of the Journal of Vascular Surgery® evaluates the rate of reinterventions and readmissions after initial abdominal aortic aneurysm (AAA) repair, 30-day mortality and the effect on long-term survival.

Cases of 45,652 Medicare beneficiaries who underwent AAA-related or laparotomy-related EVAR (50 percent) or open repair (50 percent) from 2001 to 2004, were reviewed by researchers from Beth Israel Deaconess Medical Center and the Department of Health Policy at Harvard Medical School in Boston, Mass. as well as the Centers for Medicare and Medicaid Services in Baltimore, MD.

"We knew that AAA-related reinterventions are more common after EVAR, whereas laparotomy related reinterventions are more common after open repair," said Marc L. Schermerhorn, MD, vascular surgeon at Beth Israel Deaconess Medical Center and an associate professor at Harvard Medical School.

Dr. Schermerhorn added that despite a perioperative benefit with EVAR, researchers found that late survival rates were similar to those undergoing open surgery. During the six year follow-up period, overall reinterventions or readmissions accounted for 9.6 percent of all EVAR deaths and 7.6 percent of all open repair deaths.

Hospitalizations for ruptured AAA without repair and for bowel obstruction or ventral hernia without abdominal surgery were recorded. Event rates were calculated per year and were presented through follow-up as events per 100 person-years. Thirty-day mortality was calculated for each reintervention or readmission.

Overall reinterventions or readmissions were similar between repair methods but slightly more common after EVAR (7.6 vs.7.0/100 person-years) and overall 30-day mortality with any reintervention or readmission was 9.1 percent. The EVAR patients had more ruptures (0.50 vs. 0.09), with a mortality of 28 percent. In addition, EVAR patients had more AAA-related reinterventions through 6 years (3.7 vs. 0.9; mortality, 5.6 percent), most of which were minor endovascular reinterventions (2.4 vs. 0.2) with a 30-day mortality of 3.0 percent.

Minor open reinterventions (0.8 vs. 0.5; mortality, 6.9 percent) and major reinterventions (0.4 vs. 0.2; mortality, 12.1 percent), were also more common after EVAR than open repair. Conversely, EVAR patients had fewer laparotomy-related reinterventions than open patients (1.4 vs. 3.0; mortality, 8.1 percent) and readmissions without surgery (2.0 vs. 2.7; mortality 10.9 percent).

"Our study shows that among initial AAA repair survivors, reinterventions and readmissions are slightly more common after EVAR than open repair, and likely contribute somewhat to the loss of the early survival advantage seen with EVAR," said Dr. Schermerhorn. "However, reinterventions did not fully account for the survival curves coming together after 3 years. Future work should attempt to identify predictors of reintervention or readmission to factor this into clinical decision algorithms."