Systematic review of clinical trials comparing open and endovascular treatment of abdominal aortic aneurysm

Abstract

Objective: Endovascular repair (EVAR) using stent-graft device is a new treatment for abdominal aortic aneurysm (AAA) that is gaining more and more popularity. This systematic review compares the new minimally invasive endovascular treatment with the conventional open repair aiming to provide more evidence for clinical decision on choice of treatment for aneurysm patients. Methods: Electronic search on MEDLINE, EMBASE and Cochrane Library and manual search on bibliographies was performed to identify studies published from 1991 to 2004 comparing clinical outcomes of patients who underwent EVAR and open repair. Quality of clinical studies was assessed by modified Evans and Pollok score and those scores below 50 were excluded. Systematic analysis was performed for short-, mid- and long-term clinical outcomes. The effect size of the clinical parameters was estimated by relative risk, weighted mean difference and standard mean difference. Results: 27 clinical studies and 7226 patients were included in this systematic review. Three studies were randomized control studies and the rest were comparative studies. Systematic review showed patients after EVAR had significantly lower 30-day mortality, shorter hospital and intensive care unit stay, less blood loss or blood transfusion, fewer cardiac and respiratory complications, less colonic ischaemia, and fewer overall operative morbidities. But EVAR carried a significant higher frequency of early secondary procedures and graft-related complications. The 1-5-year mortality between the two groups was similar. Patients receiving EVAR required more late secondary procedures and the cost related to EVAR was higher. Systematic review on quality of life could not be performed as there was a large variation on method of measurement. Conclusion: EVAR offers significant benefit to aneurysm patients in the early postoperative period. However, it does not show an advantage over open repair in mid- and long-term outcome. Furthermore, EVAR might carry more morbidity and higher cost in the long term. Prospective randomized control studies focusing on long-term outcome of EVAR and open repair aneurysm patients as well as on studies on newer generation devices are needed to provide more information for clinical decisions. © 2006 Blackwell Publishing Asia Pty Ltd.