EVAR Underused in Fixing Ruptured Aortic Aneurysms

BY MITCHEL L. ZOLER

PHILADELPHIA -- Endovascular aneurysm repair should be used more aggressively to treat ruptured abdominal aortic aneurysms, Dr. Richard W. Lee said at the Peripheral Vascular Surgical Society session at the Vascular Annual Meeting.

A 4-year, single-center experience repairing ruptured abdominal aortic aneurysms (AAA) suggested that endovascular aneurysm repair (EVAR) resulted in a lower mortality rate during initial hospitalization, compared with open repair. Surgeons at Strong Memorial Hospital and the University of Rochester (N.Y.) tended to use EVAR in patients who had hemodynamic stability. The main reason for using EVAR is the right aortic anatomy in the patient, but the review showed an anatomic assessment was not always used to guide the choice of repair, said Dr. Lee, a vascular surgeon at the University of Rochester.

The chart review included 52 patients with a ruptured AAA who were treated at the university during June 2002 through March 2006. The series included 17 patients who were treated with EVAR, 20 who had an infrarenal open repair, and 15 who had a pararenal open repair.

Death while in hospital occurred in 35% of patients treated with EVAR, 47% of those who had a pararenal repair, and 75% of those with an infrarenal repair. Estimated blood loss and hospital length of stay were also reduced by EVAR. (See chart.)

The overall 54% in-hospital mortality rate in the series compares with a 53% rate at the same hospital during the 4 years immediately before June 2002, Dr. Lee said.

Although EVAR appeared to cut the rate of perioperative mortality, the review raised the question of whether this finding was primarily caused by a selection bias, with a higher proportion of hemodynamically stable patients undergoing EVAR. Of the 17 patients treated with EVAR, 53% were stable, compared with 33% who those had pararenal repair and 25% of those who had infrarenal repair. Hemodynamic instability was defined as a systolic blood pressure of less than 120 mm Hg, a heart rate of more than 100 beats/min. and a respiration rate of 20 breaths/min. or greater.

But EVAR appeared to result in better survival even among unstable patients. In this subgroup, EVAR led to a 25% mortality rate, compared with a 40% death rate following pararenal repair and a 73% mortality rate following infrarenal repair.

The series review also showed that about half of the patients who underwent open repair had an aneurysm anatomy that was amenable to EVAR. To ensure that patients who are suitable are given the EVAR option, one should get a CT scan on all patients, and then decide whether EVAR is possible based on the patient's anatomy, Dr. Lee said.

In commenting on this study, Dr. Thomas Lindsay, chair division of vascular surgery, the University of Toronto, said: "This series appears to be similar to other single-center series of RAAAs [ruptured abdominal aortic aneurysms] that are repaired with EVAR. The 30-day death rates appear improved, however, longer-term data is not shown. Larger series, such as the Medicare Discharge database, identified that the early survival benefit of EVAR for RAAA was not sustained at 6 months. It seems EVAR for RAAA has the potential to alter the mortality. Vascular surgeons need to implement efficient imaging and treatment protocols to enable more patients to be treated with this therapy. As expertise with EVAR in emergency situations is disseminated to more centers, the optimistic view is that it could have a positive impact on national RAAA mortality."