The Riolan arch compensates for infra-renal abdominal aorta occlusion

The patient was a 66-year-old woman. She suffered from Takayasu’s arteritis 30 years ago and hypertension 5 years ago. Her main complaint was intermittent claudication of bilateral lower limbs; the claudication distance was approximately 500 m. Ankle-brachial index of bilateral lower extremities were 0.6(R) and 0.5(L), respectively. Computed tomography angiography of the abdominal aorta showed infrarenal abdominal aorta occlusion (A-C). The branch of superior mesenteric artery was compensatory enlargement. The blood flow was through the middle colic artery, the riolan arch, and the inferior mesenteric artery, which compensated for the distal abdominal aorta. The informed consent had been obtained from the patient before submit the image.