Abstract
OBJECTIVE: The aim of this study was to evaluate the effect of fenestration configuration and fenestration gap on renal artery outcomes during fenestrated-branched endovascular aortic repair (F/BEVAR). METHODS: A retrospective multicenter analysis was performed, including patients with complex aortic aneurysms treated with F/BEVAR that incorporated at least one small fenestration to a renal artery. The renal fenestrations were divided into groups 1 (8 × 6 mm) and 2 (6 × 6 mm). Primary patency, target vessel instability (TVI), freedom from secondary interventions (SIs), occurrence of type IIIc endoleak, all related to the renal arteries, were analyzed at 30-day, 1-year, and 5-year landmarks. The fenestration gap (FG) distance was analyzed as a modifier, and clustering was addressed at the patient level. RESULTS: A total of 796 patients were included in this study, 71.7% male, with a mean age of 73.3 ± 8.1 years. The mean follow-up was 30.0 ± 20.6 months. Of the 1474 small renal fenestrations analyzed, 47.6% were 8 × 6 mm, and 52.4% were 6 × 6 mm. At the 30-day landmark, primary patency (99.9% vs 98.0%; P value < .001 for groups 1 and 2, respectively), freedom from TVI (99.6% vs 97.1%; P value < .001 for groups 1 and 2, respectively), and freedom from SI (99.8% vs 98.4%; P value = .022 for groups 1 and 2, respectively) were higher in 8 × 6 compared with 6 × 6 fenestrations, and the incidence of acute kidney injury was similar across the groups (92.6% vs 92.7%; P value = .953 for groups 1 and 2 respectively). The primary patency at 1 and 5 years was higher in 8 × 6 fenestrations (1-year: 98.8% vs 96.9%; 5-year: 97.8% vs 95.7%, for groups 1 and 2, respectively, P values = .010 and .021 for 1 and 5 year comparisons, respectively). The freedom from SIs was significantly higher among 6 × 6 fenestrations at 5 years (93.1% vs 96.4%, for groups 1 and 2, respectively, P value = .007). The groups were equally as likely to experience a type Ic endoleak (1.3% and 1.6% for 8 × 6 and 6 × 6mm fenestrations, respectively, P = .689). The 6 × 6 fenestrations were associated with higher risk of kidney function deterioration (17.8%) when compared with 8 × 6 fenestrations (7.6%) at 5 years (P < .001). The risk of type IIIc endoleak was significantly higher among 8 × 6 fenestrations at 5 years (4.9% and 2% for 8 × 6 and 6 × 6 mm fenestrations, respectively; P = .005). A FG ≥5 mm negatively impacted the cumulative 5-year freedom from TVI (group 1: FG ≥5 mm = 0.714, FG <5 mm = 0.857; P < .001; group 2: FG ≥5 mm = 0.761, FG <5 mm = 0.929; P < .001) and the cumulative 5-year freedom from type IIIc endoleak (group 1: FG ≥5 mm = 0.759, FG <5 mm = 0.921; P = .034; group 2: FG ≥5 mm = 0.853, FG <5 mm = 0.979; P < .001) in both groups and the cumulative 5-year patency in group 2 (group 1: FG ≥5 mm = 0.963, FG <5 mm = 0.948; P = .572; group 2: FG ≥5 mm = 0.905, FG <5 mm = 0.938; P = .036). CONCLUSIONS: Fenestration configuration for the renal arteries impacts outcomes. The 8 × 6 small fenestrations have better patency at 30 days, 1 year, and 5 years, whereas 6 × 6 small fenestrations are associated with lower rates of SIs, primarily due to a lower incidence of type IIIc endoleaks. FG ≥5 mm at the level of the renal arteries significantly impacts the freedom from TVI, freedom from type IIIc endoleak, and 5-year patency independently of the fenestration size or vessel diameter.