(PC052) Open Surgical Management Of Abdominal Aortic Aneurysm With Congenital Duplicate Right Common Iliac Artery

Objectives: A 69-year-old male with a history of tobacco use and hypertension was referred for evaluation of an enlarging abdominal aortic aneurysm (AAA). He had undergone CTA demonstrating a 5.7cm infrarenal AAA, calcified but patent right common iliac artery (CIA), and a duplicate right CIA emerging from the posterior aorta, coursing over the pelvic brim, eventually joining the external iliac artery (Figure 1). Imaging also showed absence of bilateral internal iliac arteries (IIAs). With patient consent obtained, this report aims to describe an open surgical approach to AAA repair in the context of aberrant iliac artery anatomy.

Methods: A standard endovascular aortic repair was considered; however, two factors redirected our methodology to open surgical repair. First, the patient was robust with few comorbid conditions. Second, the patient is without IIAs and has robust collateralization through the IMA indicating a high risk of pelvic/colorectal ischemia with standard endovascular repair.

In our midline, open approach, we placed an infrarenal aortic clamp allowing visualization of the aortic sac and iliac anatomy (Figure 2). After performing a local endarterectomy of the infrarenal aorta, a 16x8mm bifurcated graft was anastomosed with the left CIA and the duplicate right CIA. The native CIA being small and heavily calcified was tied. After unclamping, our repair was hemostatic and the patient had palpable femoral and DP pulses.

Results: Following the procedure, the patient’s lower right extremity perfusion via the duplicate CIA was closely monitored. He had no complaints of claudication, abdominal pain, or other post-operative complications. The post-operative day 30 CTA demonstrated an intact bifurcated aortic graft, patent duplicate right CIA, and the ligated native right CIA was thrombosed. Duplex ultrasound demonstrated normal, multiphasic flow throughout the lower extremities.

Conclusions: Several case reports in the existing literature describe congenital absence of unilateral or bilateral CIAs; however, this is the first documented case of a duplicate CIA. Previously documented CIA anomalies were similarly discovered incidentally to other vascular problems like lower limb ischemia or genitourinary malformations.

We elected for an open as opposed to endovascular aneurysm repair as a precautionary measure due to the complicated iliac anatomy distal to the AAA. The duplicate iliac artery did not affect the procedure outcome as evidenced by the expected normal perfusion in the lower extremities and post-operative scans. The progression of the AAA disease and CIA anomaly will be monitored over time, but there is little to no change expected in the patient’s future management.