Anatomic characteristics associated with superior mesenteric artery stent graft placement during fenestrated para/suprarenal aneurysm repair

Objective: According to the instructions for use, fenestrated endovascular aortic aneurysm repair (FEVAR) with the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) requires ≥4 mm of nonaneurysmal infrarenal neck length, and superior mesenteric artery (SMA) stenting is optional. In the present study, we evaluated the outcomes of FEVAR with SMA stent grafting relative to SMA scallops or unstented fenestrations and their anatomic differences. Methods: We performed a single-institution retrospective analysis of patients who had undergone FEVAR with an SMA scallop or large fenestration with and without SMA stent grafting from June 2012 to May 2020 after institutional review board approval. Results: Of the 203 aneurysms repaired with ZFENs, 127 were included in our analysis. Of these 127 aneurysms, 55 had stent grafted SMA fenestrations, 38 unstented SMA fenestrations, and 34 SMA scallops. Technical success was achieved in all patients. The operative times were longer (335.5 ± 16.4 minutes vs 265.0 ± 12.8 minutes vs 269.0 ± 12.7 minutes; P < .001) and the transfusion rates were higher (33% vs 8% vs 18%; P = .01) in the SMA stent graft group. However, the fluoroscopy time (65.4 ± 3.76 minutes vs 58.3 ± 3.94 minutes vs 51.4 ± 4.75 minutes; P = .05) and contrast volume (92.2 ± 5.17 mL vs 87.1 ± 6.73 mL vs 93.1 ± 5.89 mL; P = .84) were not significantly different. Anatomically, the patients who had undergone FEVAR with a ZFEN and SMA stent grafting had had shorter infrarenal neck (1.73 ± 1.18 mm vs 4.92 ± 1.16 mm vs 6.28 ± 1.42 mm; P = .03) and infra-SMA neck (10.3 ± 1.39 mm vs 23.9 ± 1.24 mm vs 26.8 ± 1.67 mm; P < .001) lengths. In the SMA stent graft group, one patient had developed small bowel necrosis after embolization of an intraoperatively perforated jejunal branch and two had developed colonic ischemia of unclear etiology with patent SMA stent grafts found on imaging. Endograft migration and SMA occlusion with bowel ischemia occurred in one patient in the SMA fenestration group. Overall mortality (24% vs 21% vs 18%; P = .82) and 30-day mortality (5% vs 3% vs 3%; P = .80) were comparable between the three groups. In addition, the incidence of type III endoleak (5% vs 3% vs 3%; P = .45) and the need for reintervention (20% vs 18% vs 12%; P = .60) were similar across all three groups. The mean follow-up duration was longer for the SMA scallop group, which can be attributed to 82% of these occurring in the first one half of the study period. Conclusions: Despite the added technical complexity, SMA stenting enabled FEVAR in patients with pararenal and suprarenal aneurysms with high rates of technical success and no increased risk of mortality, major adverse events, type III endoleaks, or reintervention.