Unique Complications and Failure Modes of Iliac Branch Devices.

OBJECTIVES Iliac branch devices (IBDs) are modular, bifurcated endografts designed to preserve hypogastric flow during endovascular aortoiliac aneurysm repair. We report our single center outcomes, and describe the unique complications of these devices: inability to cannulate the hypogastric artery (technical failure), occlusion of the internal branch, and type III endoleak from separation of components between the main body and IBD. METHODS A prospectively maintained institutional database of patients undergoing IBD implantation between 2014 and 2019 was reviewed. Technical and clinical outcomes were evaluated. We then identified patients having one of the IBD-specific complications and patient, anatomic, and procedural data were analyzed to identify factors associated with these failures. RESULTS 64 IBDs were placed in 59 patients during the study period. Mean age was 71.2±8.6, and 92% were male. 74.6% of patients had a current or prior abdominal aortic aneurysm, and 9.4% had a hypogastric aneurysm. Technical success was achieved in 60/64 cases (93.8%); prior EVAR was associated with technical failure (p=0.04). There were 5 instances of component separation between the main body and the IBD: 3 occurred intraoperatively and were repaired with additional bridging components, and 2 occurred on late follow-up and required reintervention. Increased tortuosity index of both aortoiliac (1.7±0.4 vs. 1.3±02, p=0.04) and iliac-specific (3.9±2.4 vs. 1.9±0.9, p=0.03) segments were significantly associated with component separation, as was the use of larger internal iliac components (13.9±2.4 vs. 11.1±2.3 mm, p=0.04). Internal branch occlusions occurred in 4 patients (6.7%). Two were successfully reopened with endovascular procedures, with two being asymptomatic. No specific factors were found to be predictive of branch occlusion. CONCLUSIONS IBD-specific complications occur rarely. History of prior EVAR is associated with technical failure, while increased aortic and iliac tortuosity are predictive of component separation and type III endoleak. Severe tortuosity should be carefully considered when planning for IBD.