Detection of Late Complications After Endovascular Abdominal Aortic Aneurysm Repair and Implications for Follow-up

Abstract

Introduction: Endovascular aneurysm repair (EVAR) is associated with risk of late complications, and requires follow-up. The frequency of follow-up and the optimal imaging modality(ies) for detection of post-EVAR complications is, however, a matter of debate. This study assesses post-EVAR complications and reinterventions in a two-center cohort. The study hypothesis was that a majority of post-EVAR complications are either symptomatic, or can be detected with ultrasound surveillance alone. Methods: All EVAR patients from 1998-2012 in two centers were included (follow-up routine: post-EVAR imaging at 1, 6, 12 months, and annually thereafter). Preoperative clinical and anatomical parameters, operative data and long-term outcome were assessed. Post-EVAR complications were classified based on if they were symptomatic or imaging detected. For patients who had undergone ultrasound (DUS) and computed tomographic angiography (CTA) imaging within three months from each other, kappa coefficient of agreement was assessed. Results: Some 454 patients treated with EVAR were identified, with a mean follow-up of 4.9 (range 0-18) years, 118 patients (26%) developed 176 complications, 42 had more than one complication. There was no difference in preoperative parameters between patients with or without complications. One-hundred-and-six (60.2%) of the complications were asymptomatic imaging detected, and 70 (39.8%) were symptomatic; 39.2 % occurred during the first year post-EVAR, 25.6 % during years 2-3, and 19.9 % during years 4-5. Forty-four percent of asymptomatic complications were primarily detected with DUS. Two-hundred-fifty three patients had imaging with the both modalities within 3 months from each other; the kappa coefficient for agreement between CTA and ultrasound for detecting clinically significant complications was 0.91. Ultrasound failed to detect three type I endoleaks, all three had short sealing in the first postoperative CTA. Conclusion: Approximately one fourth of the patients developed post-EVAR complications, the majority of which were asymptomatic and imaging detected, underlining the importance of adequate surveillance. There was a good agreement between CTA and ultrasound in detecting complications, with a high negative predictive value for ultrasound, indicating that follow-up with the DUS, as the primary surveillance strategy after EVAR is safe in patients with adequate sealing measured on the first postoperative CTA.