Evaluation of Collateral Source Characteristics With 3‐Dimensional Analysis Using Micro–X‐Ray Computed Tomography

BACKGROUND: Collateral arteries provide an alternative blood supply and protect tissues from ischemic damage in patients with peripheral artery disease. However, the mechanism of collateral artery development is difficult to validate. METHODS AND RESULTS: Collateral arteries were visualized using micro–x‐ray computed tomography. Developmental characteristics were assessed using confocal microscopy. We conducted a single‐center, retrospective, observational study and assessed the dilatation of collateral arteries on ischemic sides. We quantified the vascular volume in both ischemic and nonischemic legs. A prominent increase in vascular volume was observed in the ischemic leg using a murine hind‐limb ischemia model. We also performed qualitative assessment and confirmed that the inferior gluteal artery functioned as a major collateral source. Serial analysis of murine hind‐limb vessel development revealed that the inferior gluteal artery was a remnant of the ischial artery, which emerged as a representative vessel on the dorsal side during hind‐limb organogenesis. We retrospectively analyzed consecutive patients who were admitted for the diagnosis or treatment of peripheral artery disease. The diameter of the inferior gluteal artery on the ischemic side showed significant dilatation compared with that on the nonischemic side. CONCLUSIONS: Our findings indicate that an embryonic remnant artery can become a collateral source under ischemic conditions. Flow enhancement in the inferior gluteal artery might become a novel therapeutic approach for patients with peripheral artery disease.