Study Evaluates Outcomes of Suprarenal Versus Infrarenal Fixation in EVAR for Routine and All Users

August 23, 2017—A study of renal complications after endovascular abdominal aortic aneurysm repair (EVAR) with suprarenal versus infrarenal fixation among all users and routine users was published by Sara L. Zettervall, MD, et al on behalf of the Vascular Study Group of New England (VSGNE) in European Journal of Vascular and Endovascular Surgery (EJVES; 2017;54:287–293). The data were first presented at the Society for Vascular Surgery's 2016 Vascular Annual Meeting, which was held in National Harbor, Maryland, on June 7–11, 2016.

The investigators noted that previous studies comparing endografts with suprarenal and infrarenal fixation for EVAR have found conflicting results and did not account for differences in patient selection. The current study aims to evaluate the differences in outcomes among surgeons who routinely use either suprarenal or infrarenal fixation, as well as all surgeons in the VSGNE.

As summarized in EJVES, the investigators identified all patients who had undergone EVAR in the VSGNE from 2003 to 2014. All ruptured aneurysms, repairs with concomitant procedures, and infrequently used stent grafts (< 50) were excluded.

In the study, suprarenal endografts included Talent (Medtronic), Zenith (Cook Medical), and Endurant (Medtronic). Infrarenal endografts included AneuRx (Medtronic) and Excluder (Gore & Associates). Grafts were compared among surgeons who used only one type of endograft (suprarenal or infrarenal) for > 80% of cases, as well as all surgeons. Multivariate regression and Cox hazard models were utilized to account for patient demographics, comorbidities, operative differences, and procedure year.

This study identified 2,574 patients (suprarenal, 1,264; infrarenal, 1,310) with 888 endografts placed by routine users (suprarenal, 409; infrarenal, 479).

The investigators reported that there were no differences in baseline comorbidities, including the estimated glomerular filtration rate, between suprarenal and infrarenal fixation or between patients with endografts placed by routine and nonroutine users. Patients treated with suprarenal endografts received more contrast with all users (102 vs 100 mL; P = .01) and routine users (110 vs 88 mL; P < .01), but other vascular and operative details were similar.

Among all users, patients treated with suprarenal grafts had higher rates of creatinine increase > 0.5 mg/dL (3.7% vs 2%; P = .01), length of hospital stay > 2 days (27% vs 19%; P < .01), and discharge to a skilled nursing facility (9.2% vs 6.7%; P = .02).

There were no differences in 30-day or 1-year mortality. After adjustment, suprarenal stent grafts remained associated with an increased risk of renal deterioration (odds ratio [OR], 2; 95% confidence interval [CI], 1.2–3.4) and prolonged length of hospital stay (OR, 1.8; 95% CI, 1.4–2.2). Among routine users, suprarenal fixation was also associated with higher rates of renal dysfunction (3.7% vs 1.3%; OR, 2.9; 95% CI, 1.1–7.8; P = .02).

The investigators concluded that despite potential differences in patient selection, endografts with suprarenal fixation among all users and routine users were associated with higher rates of renal deterioration and longer lengths of hospital stay. Longer-term data are needed to determine the duration and severity of renal function decline and to identify potential benefits of decreased migration or endoleak, advised the investigators in EJVES.