Adverse consequences of internal iliac artery occlusion during endovascular repair of abdominal aortic aneurysms

Objective: Embolization of the internal iliac artery (IIA) may be performed during endovascular abdominal aortic aneurysm (AAA) repair if aneurysmal disease of the common iliac artery precludes graft placement proximal to the IIA orifice. The IIA may also be unintentionally occluded because of iliac trauma or coverage by the endograft. The purpose of this study was to determine the incidence, etiology, and consequences of IIA occlusion during endoluminal AAA repair. Methods: Over 2 years, 96 patients have undergone endoluminal AAA repair. The details of the operative procedure, reasons for IIA occlusion, perioperative complications, and clinical follow-up were recorded. Results: The IIA was intentionally occluded in 15 patients (16%) to treat 13 common iliac artery aneurysms, one IIA aneurysm, and one external iliac artery aneurysm. The IIA was unintentionally occluded in 9 patients (9%), resulting from traumatic iliac dissection in 5 patients and coverage of the IIA by the endograft in the remaining 4 patients. Three patients had colon ischemia. One patient with a unilateral IIA occlusion had sigmoid infarction necessitating resection. The other two patients underwent intentional occlusion of one IIA followed by unintentional occlusion of the contralateral IIA because of a traumatic iliac dissection. Both had postoperative abdominal pain and distention; rectosigmoid ischemia was revealed through colonoscopy. Conservative treatment with bowel rest and broad-spectrum antibiotics was successful in both cases. Nondisabling hip and buttock claudication occurred in seven patients (32%) at 1 month but resolved by 6 months in three of these patients. Conclusion: Embolization of the IIA for iliac aneurysmal disease and unintentional IIA occlusion due to trauma or graft coverage occurs in a considerable number of patients undergoing endoluminal AAA repair. Most patients with unilateral occlusion do not experience colon ischemia or disabling claudication. Therefore, unilateral embolization of the IIA is well tolerated and allows for the endoluminal treatment of patients with both an AAA and an iliac artery aneurysm, thereby expanding the number of patients who can be managed with an endovascular approach. Although acute, bilateral IIA occlusions should be avoided, significant consequences were not observed in our small series of patients.