EVAR Outcomes Compared With Approved Devices Versus Investigational Devices

March 21, 2018—An evaluation of the nature and outcomes of reinterventions after endovascular aneurysm repair (EVAR) using devices approved by the US Food and Drug Administration (FDA) versus investigational trial devices was published by Alexander S. Fairman, MD, et al in Journal of Vascular Surgery (JVS; 2018;67:1082–1090).

As background, published rates of reintervention after EVAR range from 10% to 30%. The investigators evaluated their university center's experience with reinterventions in the context of FDA-approved and trial devices. The investigators are from the Division of Vascular Surgery and Endovascular Therapy at the Hospital of the University of Pennsylvania in Philadelphia, Pennsylvania.

As summarized in JVS, the investigators performed retrospective data collection for patients who underwent infrarenal EVAR and required reintervention from 2000 to 2016. Trial devices included those used in FDA feasibility and pivotal trials. Time-to-event analysis was performed using Cox regression. Predictors of mortality and explantation were evaluated using logistic regression, and survival analysis was performed using Kaplan-Meier methods.

The data included 1,835 EVAR procedures performed between 2000 and 2016. There were 137 patients (116 men; mean age, 72.2 ± 10 years) who underwent reintervention (mean aneurysm size, 5.9 ± 1.2 cm). The median follow-up was 5 years with an overall survival of 70.1%.

The investigators reported that the overall reintervention rate was 7.5%. With FDA-approved devices, the reintervention rate was 6.4%, whereas the rate was 14.4% with trial devices (P < .001).

For all devices, the most common cause of reintervention was type II endoleak (52.5%), followed by type I endoleak (18.2%), type III endoleak (9.5%), limb kink (7.3%), iliac occlusive disease (5.8%), endotension (1.5%), and other. The overall mean time to first reintervention was 2.3 ± 2.5 years, and univariate Cox regression identified male gender (hazard ratio, 1.91; 95% confidence interval [CI], 1.17–3.1; P = .01) and age at the time of EVAR (HR, 1.03; 95% CI, 1.01–1.05; P = .006) as risk factors for time to first reintervention. Among patients requiring reintervention, the mean number of reinterventions for trial devices was significantly greater than that for FDA-approved devices (2.18 vs 1.65; P = .01).

Trial devices requiring reintervention had approximately threefold higher odds for requiring more than two reinterventions (odds ratio [OR], 2.88; 95% CI, 1.12–7.37; P = .034). Trial device, cause of reintervention, and type of reintervention were not predictive of the need for explantation or mortality, but the number of reinterventions was significantly associated with the need for explantation (OR, 1.86; 95% CI, 1.17–2.96; P = .012). EVAR device and the need for explantation did not have an impact on mortality.

The investigators concluded that despite the rigorous nature of patient enrollment in clinical trials and the development of newer iterations of investigational devices, patients undergoing EVAR with trial devices are more likely to undergo a greater number of reinterventions than with FDA-approved devices. Although mortality and the need for explantation were not significantly associated with trial devices, the finding of a greater number of reinterventions highlights the need to properly inform patients willing to partake in investigational device trials, advised the investigators in JVS.