Midterm Outcomes With the Nellix Endograft Alone or With Chimneys

Introduction: Endovascular aneurysm sealing (EVAS) appeared to be an innovative alternative to conventional endovascular abdominal aortic aneurysm repair. However, high rates of midterm failure of EVAS led to withdrawal of the device from the market. The study aim was to report midterm outcomes of patients treated with EVAS alone or associated with chimneys (Ch-EVAS) and the management of their complications. Methods: In this single centre study, all consecutive Nellix implants between 2013 and 2016 were included. The primary endpoint was device failure: (1) a triad of caudal migration of the Nellix stents > 5 mm, separation of the endobags (>5 > 5 mm), and sac enlargement (>5 > 5 mm), with or without visible endoleak, (2) secondary aneurysm rupture, (3) surgical explant of the graft, or (4) any intervention for a type I endoleak. Overall mortality, aneurysm related mortality, and re-intervention rates were analysed. Results: Fifty patients (male n = 43, female n = 7) were included. Median follow-up was 3.05 years (interquartile range [IQR] 0.52, 4.63) and follow up index was 0.51 (IQR 0.10, 0.88). Device failures occurred in 17 patients (34%). Overall and aneurysm related mortality rates during the follow up period were 30% and 13%. Fourteen (28%) patients required re-interventions. Five EVAS patients (17%) presented with complications. Type Ia endoleaks were managed by device explantation for three patients, and endovascular aneurysm repair in Nellix for two patients. Type Ib endoleaks were managed with an iliac branched device and limb extension. Nine ChEVAS patients (42.9%) presented with complications. Type Ia endoleaks were was managed by Nellix stent prolongation and renal extension, two multibranched thoraco-abdominal devices, and two device explantations. Type Ib endoleaks were managed by limb extension and stent complications by stent angioplasty and iliorenal bypass. Conclusion: The midterm outcome of EVAS is poor. All patients who underwent EVAS implantation must be informed and should undergo frequent surveillance. Open repair and device explantation should be considered as the primary treatment. (c) 2024 The Author(s). Published by Elsevier Ltd on behalf of European Society for Vascular Surgery. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Article history: Received 9 October 2022, Revised 15 May 2024, Accepted 18 June 2024,