The effect of manufacturer's instructions for use compliance on Cook ZBIS iliac-branched endograft long term outcomes.

Abstract: Objective Current guidelines indicate iliac branched endografts as the ideal means to preserve pelvic perfusion during endovascular aortic repair. Since 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. Aim of this study is to evaluate long-term outcomes obtained using the Cook ZBIS endograft in the treatment of aorto-iliac aneurysms according to or outside manufacturer’s instruction for use. Methods Data from all patients who underwent iliac branched endograft (IBD) implant in a single centre were reviewed. Study population was divided into two subgroups: Group I treated according to manufacturer’s instructions for use (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 according to 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 aorto-iliac aneurysms both inside and outside IFU. Anyway a lower target hypogastric patency rate should be expected when treating patients with hypogastric aneurysms.