Late Open Semi-conversion with Endograft Preservation for (Type II) Endoleaks with Late Aneurysm Sac Enlargement after EVAR - Indications, Method and Results in Our Own Patient Collective

Abstract

EVAR (endovascular aortic repair) is the most common method for treating an abdominal aortic aneurysm, but according to the latest findings it carries the risk of subsequent complications. These can be caused by (late) aneurysm sac growth. If conservative and surgical therapies fail to treat the aneurysm sac growth, open conversion is necessary to prevent aneurysm rupture. There are several options for open conversion, in which the EVAR prosthesis can be completely preserved or is (partially) removed. Late open semi-conversion with complete in-situ preservation of the EVAR-prosthesis and gathering of the aneurysm sac are a less invasive method than complete conversion and may be performed instead for selected patients. The aim of the present work is to present the surgical method, including indications and technical information, as well as the presentation of the results in our recent patient collective.All patients semi-converted in our department of vascular surgery and phlebology due to (type II) endoleak were included. All data are presented as n (%) or median (range).Between 6/2019 and 3/2023, 13 patients underwent semi-conversion 6 (2-12) years (median, range) after the initial EVAR. The aneurysm sac diameter at the time of semi-conversion was 69mm (58-95mm), the operating time was 114min (97-147min), the blood loss was 100ml (100-1500ml). Five (38%) patients received blood transfusion intraoperatively and 2 (15%) postoperatively. The stay in the intensive care unit lasted 1 (1-5) days, the hospitalisation time was 8 (6-11) days. Postoperative complications were intestinal atony (3 [23%], 1 [8%] with nausea/emesis and gastric tube insertion), anaemia (2 [15%]), hyponatraemia (2 [15%]), delirium (1 [8%]), COVID-19 infection (1 [8%]) and 1 [8%] intra-abdominal postoperative bleeding with the indication for surgical revision and the transfusion of 8 erythrocyte concentrates.Semi-conversion is a safe and practicable surgical method with few severe complications for a selected group of patients, which should be considered as an alternative to more invasive methods with (partial) removal of the EVAR-prosthesis. Further long-term studies comparing semi-conversion to full conversion are needed to demonstrate its benefits.