Novel Risk Stratification Used to Compare EVAR and Open Repair Outcomes in Ruptured AAA

June 3, 2015—In the Journal of Vascular Surgery, findings from a study of patients with ruptured abdominal aortic aneurysms (rAAA) treated with endovascular aneurysm repair (EVAR) versus open repair (OR) were published by Mujtaba M. Ali, MD, et al (2015;61:1399–1407). The study results were first presented last year at the 2014 Vascular Annual Meeting of the Society for Vascular Surgery, which was held June 5–7 in Boston, Massachusetts.

The investigators stated that the background of the study is that previous studies have reported that EVAR of rAAA has lower postoperative mortality than OR, but that comparisons involved heterogeneous populations that lacked adjustment for preoperative risk. In this study, the investigators hypothesized that for rAAA patients stratified by a validated measure of preoperative mortality risk, EVAR has lower in-hospital mortality and morbidity than OR.

As summarized in the Journal of Vascular Surgery, the investigators compared in-hospital mortality and morbidity after EVAR and OR of rAAA in patients from the Vascular Quality Initiative (2003–2013) who were stratified by the validated Vascular Study Group of New England rAAA risk score into low-risk (score, 0–1), medium-risk (score, 2–3), and high-risk (score, 4–6) groups.

The investigators reported that among 514 patients who underwent EVAR and 651 patients who underwent OR of rAAA, EVAR had lower in-hospital mortality (25% vs 33%). In risk-stratified patients, EVAR trended toward a lower mortality in the low-risk group (n = 626; EVAR, 10% vs OR, 15%), had a significantly lower mortality in the medium-risk group (n = 457; EVAR, 37% vs OR, 48%), and had no advantage in the high-risk group (n = 82; EVAR, 95% vs OR, 79%). Across all risk groups, cardiac complications (EVAR, 29% vs OR, 38%), respiratory complications (EVAR, 28% vs OR, 46%), renal insufficiency (EVAR, 24% vs OR, 38%), lower extremity ischemia (EVAR, 2.7% vs OR, 8.1%), and bowel ischemia (EVAR, 3.9% vs OR, 10%) were significantly lower after EVAR than after OR. 

Across all risk groups, median (interquartile range) intensive care unit length of stay (EVAR, 2 [1–5] days vs OR, 6 [3–13] days) and hospital length of stay (EVAR, 6 [4–12] days vs OR, 13 [8–22] days) were lower after EVAR.

This novel risk-stratified comparison using a national clinical database showed that EVAR of rAAA has a lower mortality and morbidity compared with OR in low-risk and medium-risk patients, and that EVAR should be used to treat these patients when anatomically feasible. For rAAA patients at the highest preoperative risk, there is no benefit to using EVAR compared with OR, concluded the investigators in the Journal of Vascular Surgery.