Outcomes of FEVAR and BEVAR to Treat Secondary Type 1 Endoleak After EVAR: A Prospective Multicentre Study

Overview

Ten percent of the population above 60 years develops an aortic abdominal aneurysm. In case of rupture, this pathology leads to death in more than 70% of the cases. Over the past ten years, Endovascular Aortic Aneurysm Repair (EVAR) has been the most used technique for elective treatment for abdominal aortic aneurysms (AAA) in patients with a favorable anatomy. But despite excellent postoperative results with a significant reduction of mortality , a close follow-up of these patients is mandatory to detect any potential endoleaks particularly in patients with a long-life expectancy. Failed Endovascular Infrarenal Aortic Aneurysm Repair (EVAR) with development of a proximal endoleak exposes the patient to the risk of rupture and must be treated. This type of endoleaks are often related to dilatation of the proximal neck of the AAA, and of the suprarenal aorta, making the use of any aortic fixation system, or uncovered stent ineffective. In these cases, open surgical conversion with stent graft removal is possible but at the price of a significant morbidity and mortality. The alternative is the use of a fenestrated or branched stent graft (F/BEVAR) extending the proximal sealing zone to a non-diseased aorta. The goal of this study was to evaluate the technical feasibility, early and midterm outcomes of (F/BEVAR) in patients with a proximal endoleak following a standard EVAR. The investigators performed a multicentre study between January 2010 and December 2019 in 8 French University Centres which included 85 patients with 3 years of post operative follow-up.

Between January 2010 and December 2019, all patients (n=85) who developed after EVAR, a secondary type IA endoleak, and received a F/BEVAR stent graft were entered in a prospective multicentre study bringing together 8 French university centres. Type IA secondary endoleak was defined as an endoleak appearing during follow-up, but absent on computed tomography angiography (CTA) within 30 days of EVAR. All aetiologies leading to the development of this endoleak were recorded in the study, including any abnormality of the infra-renal stent graft, any aneurysmal evolution of the neck of the infra-renal aneurysm, and any aneurysmal evolutionof the inter-renal or thoracoabdominal aorta. All patients gave their informed consent for the operation. Following the European regulation on data management, the database was anonymised, upon completion. All patients had a preoperative assessment of cardiac, renal, respiratory function and underwent an ASA physical status classification. All preoperative imaging were performed on \<1.5 mm slices. All F/BEVAR were performed using a COOK Zenith stent graft (Cook Medical Inc. Bloomington, Ind). The number of fenestrations used was based on the preoperative sizing made from 3D-CTA reconstructions. The investigators only used on-label F/BEVARs which were approved by the Zenith cook planning centre. Procedures were performed under general, epidural or local anaesthesia, depending on the preference of the anesthesiologist, surgeon or patient. Procedures were performed in a conventional operating theatre or a hybrid room as described elsewhere. General postoperative complications included any cause mortality. Acute kidney injury was defined following the KDIGO criteria , and myocardial infarction according to the generally accepted criteria. Postoperative respiratory complications were defined by the need for mechanical ventilation for more than 48 hours or re-intubation. SCI was classified according to the severity of the American Spinal Injury Association score and stroke was classified according to National Institute of Health Stroke Scale (NIHSS) . The European Society for Vascular Surgery guidelines were used to define technical success, major adverse events, aneurysm sac changes, endoleak and device integrity . F/BEVAR procedures were analysed in an intention to treat. A procedure was considered successful if the stent graft was implanted without any Type IA or type III endoleak, and with patent target arteries on peroperative angiography and on CTA or contrast enhanced ultrasound performed within the first week following the procedure. Target artery instability was defined as any branch-related death, rupture, occlusion or reintervention for stenosis, kink, endoleak, or disconnection. Monitoring during follow-up was carried out by CTA, at 3, 6 and 36 months thereafter. Any endovascular or open revision related to the procedure was recorded during follow-up. Univariate analysis was performed using t-tests for normally distributed continuous variables, and Wilcoxon rank sum test for non-normally distributed continuous variables. Chi-square or Fisher tests was used when appropriate for categorical variables. Time dependent outcomes including patient survival, freedom from reintervention, freedom from endoleak and target arteries patency were reported using Kaplan-Meier time-to-event method. A p-value \< .05 was used to assess statistical significance. All analyses were performed with SPSS V26, (IBM Corp.) and Medcalc ®.