Pelvic collateral pathway during endovascular aortoiliac aneurysm repair with internal iliac artery interruption: a retrospective observational study

BACKGROUND: Ipsilateral branches of the deep femoral artery (DFA) are qualitatively identified as collateral arteries based on angiography after internal iliac artery (IIA) interruption. The purpose of this study was to quantitatively identify the major collateral pathway after unilateral IIA interruption during endovascular aortoiliac aneurysm repair to preserve the pelvic circulation and reduce the risk of ischemic complications. METHODS: The study population included 28 patients (mean age 76.3 years) with aortoiliac aneurysm who underwent endovascular aneurysm repair with unilateral IIA interruption from August 2012 to January 2020. The diameters of the bilateral preoperative and postoperative DFA, lateral femoral circumflex artery (LFCA), medial femoral circumflex artery (MFCA) and obturator artery (ObA) were measured on contrast-enhanced computed tomography using a 3-dimensional image analysis system. The measured values were evaluated and analyzed with a repeated measures two-way analysis of variance and Dunnett’s test. RESULTS: The postoperative diameters of the MFCA (P = 0.051) and ObA (P = 0.016) were observed to be larger than the preoperative diameters. Such increases in the MFCA (P < 0.001) and ObA (P < 0.001) diameters were only found to be significant on the unilateral side of the IIA interruption, and the diameter of the ipsilateral LFCA (P < 0.001) was also found to have significantly increased in size. However, no significant arterial extension was found on the contralateral side. CONCLUSIONS: The ipsilateral MFCA-ObA pathway might therefore be a major collateral pathway arising from the DFA to preserve pelvic circulation after unilateral IIA interruption.