The Effect of Manufacturer's Instructions for Use Compliance on Cook ZBIS Iliac-Branched Endograft Long-Term Outcomes

Background: Current guidelines indicate iliac-branched endografts (IBDs) as the ideal means to preserve pelvic perfusion during endovascular aortic repair. Because patient vascular anatomy represents the main limitation to extensive use of these devices, off-label application may be considered to expand the number of patients being treated. The aim of this study is to evaluate long-term outcomes obtained using the Cook ZBIS endograft in the treatment of aortoiliac aneurysms as per or outside manufacturer's instruction for use (IFU). Methods: Data from all patients who underwent IBD implant in a single center were reviewed. Study population was divided into two subgroups: Group I treated as per manufacturer's IFU and group II treated outside IFU. Results: During the study period (2008-2018), 119 patients were treated with 130 IBDs. Eighty-six patients were treated as per IFU (group I) and 44 outside IFU (group II). Overall technical success was 99.2%. Mean follow-up was of 63.5 +/- 38.3 months for group I and 58.3 +/- 35.9 months for group II (P = 0.45). Freedom from reintervention at ten years was 79.8% in group I and 69.6% in group II (P = 0.29). Freedom from IBD-related reintervention rate was 98.7% and 95.3% in groups I and II, respectively (P = 0.240). Iliac-branched module thrombosis occurred significantly more in patients treated outside IFU with 4 cases in group I (4.7%) and 10 cases in group II (22.7%), (P = 0.005). Cox regression analysis identified hypogastric artery aneurysm as the only independent predictor for both IBD thrombosis and hypogastric artery occlusion during follow-up. Conclusions: When used by an experienced team, Cook IBDs are safe and effective in the treatment of aortoiliac aneurysms both inside and outside IFU. Anyway a lower target hypogastric patency rate should be expected when treating patients with hypogastric aneurysms.