Mid-Term Outcomes of Late Open Conversion with Endograft Preservation for Sac Enlargement after Endovascular Abdominal Aortic Aneurysm Repair

Late open conversion has sometimes been required for sac enlargement after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm. Though the open repair with endograft preservation is considered less invasive compared to endograft removal, the mid-term outcomes are still unclear. The aim of this study is to evaluate the mid-term outcomes of late open conversion with endograft preservation after EVAR. We reviewed patients who underwent late open conversion with endograft preservation for sac enlargement or rupture in our institution from May 2007 to December 2020. The open repair mainly consisted of ligation of lumber arteries or the median sacral artery and sacotomy. We additionally performed wrapping of plicated aneurysm with equine pericardium as much as possible. Patients were followed-up by a computed tomography scan and duplex ultrasound 1 and 6 months postoperatively, and each year thereafter. Of the 1,087 patients who underwent EVAR, 23 patients with a mean age of 81.5 years were included in this study. The mean duration post-EVAR was 35.6 months. Sac wrapping with equine pericardium was performed in 14 patients (60.9%). We additionally performed wrapping of the endograft junction by a Dacron knitted fabric in 1 case with type III endoleak and aortic neck banding in 4 cases with type I endoleak. The 30-day mortality was 0% and the rate of major complications was 4%. All-cause mortality was 21.7% which included 1 aneurysm-related death during a mean follow-up of 38.5 months. Sac re-enlargement was observed in 4 patients without the wrapping method. At 3 years, the aneurysmal diameter in the nonwrapping group significantly increased, compared with the wrapping group (P = 0.011). Late open conversion with endograft preservation is a feasible treatment; however, at times re-enlargement of the sac aneurysm occurs. The wrapping method has the potential to prevent sac re-enlargement after open conversion. •Late open conversion with endograft preservation is associated with good short-term outcome.•Late open conversion with endograft preservation sometimes results in sac re-enlargement in the mid-term period.•Sac wrapping technique with bio-prosthetic materials is a feasible way to prevent sac re-enlargement after late open conversion.