Leriche syndrome: A closer look at a rare and critical aortoiliac occlusion.

Collateral pathways in aortoiliac occlusive disease play a crucial role in maintaining blood flow to the abdomen, pelvis, and lower limbs. These pathways include systemic-to-systemic, visceral-to-visceral, and systemic-to-visceral connections. CT angiography is the primary imaging modality for diagnosing aortoiliac occlusion, offering detailed visualization of stenotic arteries and collateral pathways, particularly when enhanced by 3D reconstruction. This case report presents a 65-year-old male with poorly controlled hypertension, type 2 diabetes, and a 45-pack-year smoking history, who presented with progressively worsening claudication and rest pain. Imaging revealed thrombotic occlusion of the infrarenal aorta extending into the iliac arteries, with the development of collateral pathways. We also discuss the impact of erectile dysfunction severity and highlight evolving endovascular treatments such as CERAB, which show promising outcomes. This article aims to familiarize radiologists with the common patterns of aortoiliac occlusion and the associated collateral arterial pathways visible on CT angiography.