Long-term Results of Renal Artery Patency in Physician-modified Endografts for Juxtarenal Aneurysms

Abstract

Renal artery stents are commonly placed in physician-modified fenestrated endografts for juxtarenal aortic aneurysms, but long-term outcomes of these stents is unknown. The purpose of this study was to identify the long-term outcome of stented renal arteries in patients who undergo a physician-modified endovascular graft (PMEG) for repair of juxtarenal aortic aneurysms. Data were prospectively collected on patients treated with PMEG from August 2011 to September 2019 in a prospective, consecutively enrolling investigational device exemption clinical trial (NCT #01538056). Anatomic criteria, including native renal artery stenosis and angulation, were systematically measured using preoperative computed tomography. The primary outcome of renal artery reintervention after PMEG was assessed with Kaplan-Meier survival estimation. Cox proportional hazard models were used to predict renal artery reintervention after PMEG, adjusting for preoperative demographic and patient risk factors, antiplatelet use prestent and poststent placement, and evidence of preoperative stenosis by duplex criteria. We studied 141 patients who underwent PMEG during the study period, representing 282 renal arteries. During the study period, 246 out of 282 (87%) renal arteries were stented. Inability to cannulate the renal artery as the most common cause (n = 9) of inability to stent the artery. However in 25% (n = 9) of these situations, the renal artery was preserved and in 25% (n = 9) an effective proximal seal zone was obtained without renal stenting. Preoperative ostial stenosis was present in 23% (n = 62) of renal arteries by diameter reduction and 22% (n = 58) by duplex criteria. Over a follow-up period of 5 years, 15 renal arteries in 13 patients required reintervention, for an overall reintervention rate of 6.1%. All stented renal arteries remained patent. Median follow-up was 2 years (interquartile range, 0.5-4 years). The most common cause for reintervention during the first 6 months was failure to cannulate during the initial PMEG (15%, n = 2). In-stent restenosis was the reason for reinterventions for 30% (n = 4). Long-term follow-up revealed stent separation (15%, n = 2) and type IIIc endoleak (15%, n = 2) as the most common cause for reintervention. The predicted reintervention free survival of the renal artery at 5 years is 90% (95% confidence interval, 82%-95%) (Figure). Using a Cox proportional hazard model, no significant anatomic or patient-based predictors of reintervention were identified. Renal artery stents placed during physician-modified endografts show excellent long-term durability with a low rate of reintervention. No preoperative renal artery measurements are predictive of either renal stent patency or reintervention.