Prognostic impact of juxtarenal inner vessel diameter and vertical distance in renal artery outcomes after fenestrated endovascular repair

Objective: The aim of this retrospective multicenter study is to evaluate the impact of juxtarenal inner vessel diameter (JR-IVD) and vertical distance between renal arteries (RA-VerDi) on RA instability (RAI) and associated complications in patients undergoing fenestrated endovascular aortic repair for complex aortic pathology. Methods: Patients undergoing fenestrated endovascular aortic repair with custom-made stent grafts at six referral hospitals between 2017 and 2023 were included. Data on patient demographics, anatomical characteristics, stent configurations, and outcomes were collected. Patients were divided into tertiles and categorized into three groups: JR-IVD <20 mm, JR-IVD 20 to 24 mm, and JR-IVD >24 mm. RA-VerDi was determined by measuring the distance between the center of the lowest RA and the highest RA, based on the planning specifications for each custom-made graft. The primary outcome was freedom from RAI, with secondary outcomes including RA stenosis/occlusion, endoleak, and reintervention. Statistical analyses were performed using MedCalc software, with logistic regression and Kaplan-Meier survival curves used to assess outcomes. Results: In total, 520 RAs among 260 patients were analyzed. The technical success rate was 98.7%, with a 30-day mortality rate of 2.3%. After a mean follow-up of 26.9 ± 28.1 months (range, 1-154 months), RAI was observed in 5.6% of cases, including stenosis/occlusion (3.2%) and endoleak (2.2%). Freedom from RAI at 12, 24, and 48 months was 95.8% (standard error [SE], 0.01), 93.5% (SE, 0.01), and 90.7% (SE, 0.01), respectively. JR-IVD of <20 mm was identified as a significant risk factor for RA stenosis/occlusion (P = .01), although it did not increase the risk of RAI or reintervention compared with larger JR-IVDs. A correlation was found between RA-VerDi and RAI, with smaller vertical distances associated with higher RAI risk (odds ratio, 0.89; 95% confidence interval, 0.82-0.99; P = .05), but no significant cutoff was determined. Severe RA stenosis was an independent predictor of RAI (odds ratio, 13.28; 95% confidence interval, 3.1-55.86; P = .004). Conclusions: The use of fenestrated custom-made grafts in patients with a JR-IVD of <20 mm may increase the risk of RA complications, particularly stenosis/occlusion. Although a correlation between RA-VerDi and RAI was observed, a definitive predictive cutoff could not be established. Attention should be given to patients with severe RA stenosis, because this condition seems to be an independent predictor of RAI.