Detection of Late Complications After Endovascular Abdominal Aortic Aneurysm Repair and Implications for Follow up Based on Retrospective Assessment of a Two Centre Cohort

Objective Endovascular aortic aneurysm repair (EVAR) is associated with the risk of late complications and mandates follow up. This retrospective study assessed post-EVAR complications in a two centre cohort. The study evaluated the rate of complications presenting with symptoms vs. those detected by imaging follow up. Additionally, the agreement between DUS and CTA in detecting complications was assessed in patients with both. Methods All EVAR patients from 1998 to 2012 in two centres were included. Complications were classified based on whether they were symptomatic or detected by imaging, as well as based on imaging detection modality (DUS or CTA). For patients who had undergone DUS and CTA within three months of each other, the kappa coefficient of agreement was assessed. Results Four hundred and fifty-four patients treated by EVAR were identified. The median follow up time was 5.2 (IQR 2.8–7.6) years. One hundred and eighteen patients (26%) developed 176 complications. One hundred and six (60.2%) of the complications were asymptomatic, and 70 (39.8%) were symptomatic. Two hundred and fifty-three patients had imaging with both modalities within three months of each other; the kappa coefficient for agreement between CTA and DUS for detecting clinically significant complications was 0.91. Regarding CTA as the standard modality, DUS had a sensitivity of 88.8% (95% CI 77.3–95.8%) and a specificity of 99.4% (95% CI 97.1–99.9%). Three of the complications missed by DUS were related to loss of proximal and distal seal, all occurring in patients with short sealing length on first post-operative CT scan. Conclusion Approximately a quarter of the patients developed complications, the majority of which were asymptomatic, underlining the importance of adequate surveillance. There was good agreement between CTA and DUS in detecting complications. Clinically significant complications related to inadequate seal were missed by DUS, suggesting that CTA still plays an important role in EVAR surveillance.