Outcomes of Small Renal Artery Targets in Patients Treated by Fenestrated-Branched Endovascular Aortic Repair

Objective: The aim was to evaluate renal related outcomes in patients who had incorporation of a small (<4.0 mm) renal artery (RA) during fenestrated-branched endovascular aortic repair (F-BEVAR). Methods: A total of 215 consecutive patients enrolled in a prospective F-BEVAR trial were reviewed. Computed tomography angiography centreline of flow reconstruction was used to measure mean RA diameter. Patients who had at least one <4.0 mm main or accessory RA incorporated by fenestration or directional branch (study group) were compared with patients who had incorporation of two >= 5.0 mm RAs (control group). Endpoints were technical success of RA incorporation, RA rupture and kidney loss, primary and secondary RA patency, RA branch instability and re-interventions, and renal function deterioration. Results: Twenty-four patients with 28 <4.0 mm RAs (16 accessory and 12 main RAs) were compared with 144 patients with 288 >= 5.0 mm incorporated RAs. Study group patients were significantly younger than controls (72 +/- 8 vs. 75 +/- 8 years, p = .04) and more often females (46% vs. 21%, p = .018); there were no differences in cardiovascular risk factors and aneurysm extent. Technical success was 92% for <4.0 mm and 99% for >= 5.0 mm RA incorporation (p = .05). Inadvertent RA rupture occurred in three patients in the study group (13%) and in one (1%) in the control group (p = .009) resulting in kidney loss in two study group patients (8%) and one (1%) control group patient (p = .05). At one year, primary patency was 79 +/- 9% vs. 94 +/- 1% (p < .001) and secondary patency was 84 +/- 8% vs. 97 +/- 1% (p < .001) for study vs. control group; freedom from branch instability was 79 +/- 9% vs. 93 +/- 2% (p = .005), respectively. There were no differences in re-intervention rates and renal function deterioration between the groups. The mean follow up time was 21 +/- 14 months. Conclusion: Incorporation of <4.0 mm RAs during F-BEVAR is associated with lower technical success, higher risk of arterial disruption and kidney loss, and lower patency rates at one year.