From Planning to Practice: Impact of Achieved Proximal Sealing Zone in Endovascular Aneurysm Repair (EVAR)

Background: Endovascular aneurysm repair (EVAR) is the preferred treatment for abdominal aortic aneurysms (AAAs). This study evaluated the differences between the anticipated and actual achieved proximal sealing zones for standard EVAR endografts and their potential implications in a real-world AAA population. Methods: Data from 275 consecutive EVAR patients treated with the Endurant endograft (Medtronic, Minneapolis, MN, USA) between 2009 and 2022 were retrospectively analyzed. The proximal sealing zone was calculated preoperatively (target anticipated sealing zone, TASZ) and postoperatively (real achieved sealing zone, RASZ) from computed tomography angiography (CTA) images. These metrics were evaluated by assuming that they had a truncated cone shape, calculating the cone's lateral surface by measuring the proximal and distal centerline areas and the distance between the planes. The primary outcome was the occurrence of type 1A endoleak at the longest available follow-up. Results: RASZ was significantly smaller and shorter than TASZ (p = 0.001), with an average area reduction of 24.5 mm² and a median length reduction of 3 mm. Area and cranial length loss were present even when correcting for graft positioning imperfections. In the Cox proportional hazard regression model, TASZ and RASZ lengths were both independently associated with a lower risk of type 1A endoleak (HR: 0.88, 95% CI 0.80-0.96 and HR: 0.92, 95% CI 0.86-0.99, respectively). A Kaplan-Meier analysis confirmed that patients with RASZ > 5.5 mm had a survival free from endoleak higher than patients with RASZ ≤ 5.5 mm. Conclusions: In this real-world AAA population, the achieved proximal sealing zone was significantly shorter and smaller than planned, regardless of optimal endograft placement. The early calculation of RASZ, i.e., the PSZ achieved via CTA, is critical for risk stratification and follow-up.