Lost to follow-up: a potential under-appreciated limitation of endovascular aneurysm repair

Abstract

Objective: It has long been evident that lifetime follow-up after endovascular aneurysm repair (EVAR) is necessary to identify late complications. The purpose of this study is to test the hypothesis that late follow-up rates for EVAR in routine practice are inferior to those reported from protocol-driven clinical trials, consequently contributing to avoidable events associated with poor long-term outcome.

Methods: From February 1999 to December 2005, 302 EVARs were performed and eligible for follow-up. Of these, 47 were performed as part of an industry-sponsored clinical trial (study patients). Responsibility for follow-up was assigned to a research nurse for study patients and to office clerical staff for nonstudy patients. Follow-up compliance was classified as either frequent (<1 missed scheduled appointment) or incomplete (>2 missed scheduled appointments). Overall survival and complication rates were analyzed.

Results: Of the 302 patients, 203 (67.2%) had frequent follow-up and 99 (32.8%) had incomplete follow-up. The mean follow-up was significantly better in the frequent follow-up group (34.7 +/- 22 months) vs the incomplete follow-up group (18.8 +/- 18.6 months, P < .001). The 5-year survival (63.9% frequent vs 64.0% incomplete), the 5-year reintervention rate (22.3% frequent vs 10.8% incomplete), and incidence of known endoleak (14.8% frequent vs 9.1% incomplete) were statistically similar in the two groups. The incidence of major adverse events, defined as events requiring urgent surgical intervention, was significantly increased in the incomplete follow-up group (6.1% vs 0.5%; P = .006), with nearly half of these patients dying perioperatively. There was no difference in measured outcomes for study patients compared with nonstudy patients. However, mean follow-up was significantly longer for study patients vs nonstudy patients (44.8 +/- 23.7 months vs 26.8 +/- 20.9 months; P < .001).

Conclusions: Follow-up surveillance after EVAR is less intense in practice environments outside of clinical trials. Patients with incomplete follow-up have higher fatal complication rates than patients with frequent follow-up. These data expose a potential under-appreciated limitation of EVAR, questioning whether the findings in clinical trials defining the efficacy of EVAR can be routinely extrapolated to ordinary practice.