Large Fenestrations Versus Scallops for the Superior Mesenteric Artery during Fenestrated Endovascular Aneurysm Repair: Does it Matter?

Abstract

Fenestrated endovascular aneurysm repair is an established customized treatment for aortic aneurysms with 3 current commercially available configurations for the superior mesenteric artery (SMA)-a single-wide scallop, large fenestration, or small fenestration, with the scallop or large fenestration most utilized. Outcomes comparing SMA single-wide scallops to large fenestrations with the Zenith fenestrated (ZFEN) device are scarce. As large fenestrations have the benefit of extending the proximal seal zone compared to scalloped configurations, we sought to determine the differences in seal zone and sac regression outcomes between the 2 SMA configurations. We retrospectively reviewed our prospectively maintained complex endovascular aneurysm repair database and included all patients treated with the Cook ZFEN device with an SMA scallop or large fenestration configuration at its most proximal build. All first postoperative computed tomography scans (1-30days) were analyzed on TeraRecon to determine precise proximal seal zone lengths, and standard follow-up anatomic and clinical metrics were tabulated. A total of 234 consecutive ZFEN patients from 2012 to 2021 were reviewed, and 137 had either a scallop or a large fenestration for the SMA as the proximal-most configuration (72 scallops and 65 large fenestrations) with imaging available for analysis. The mean follow-up was 35months. The mean proximal seal zone length was 19.5±7.9mm for scallop versus 41.7±14.4mm for large fenestration groups (P<0.001). There was no difference in sac regression between the scallop and large fenestration at 1year (10.1±10.9mm vs. 11.0±12.1, P=0.63). Overall, 30-day mortality (1.3% vs. 2.5%, P=0.51) and all-cause 3-year mortality (72.5% vs. 81.7%, P=0.77) were not significantly different. Reinterventions within 30days were primarily secondary to renal artery branch occlusions, with only 1 patient in the scallop group requiring reintervention for an SMA branch occlusion. Despite attaining longer proximal seal lengths, large SMA fenestrations were not associated with a difference in sac regression compared to scalloped SMA configurations at a one-year follow-up. There were no significant differences in reinterventions or overall long-term survival between the 2 SMA strategies.