Coronary-Driven Cerebral Revascularization in Type 2a Takayasu Arteritis: A Rare Multisystem Collateral Phenotype.

Takayasu arteritis (TA) is a chronic, granulomatous large-vessel vasculitis affecting the aorta and its branches. This report describes a 33-year-old woman with longstanding, unsupervised disease who developed extensive collateral revascularization, including rare coronary-carotid and coronary-vertebral pathways. Coronary angiography revealed normal epicardial coronary arteries but demonstrated collateral filling of the carotid system from the left coronary circulation. Computed tomography angiography identified complete occlusion of all aortic arch branches and extensive systemic, thoracic, pelvic, and visceral collateral pathways, including the Winslow pathway. The axillary, carotid, and vertebral arteries were supplied by new channels from the internal thoracic, intercostal, paraspinal, pelvic, and coronary arteries. This case shows a rare pattern of collateral blood flow that maintains blood supply to the brain and upper limbs in advanced Type 2a TA. It highlights the importance of using multiple imaging methods to map these complex networks for diagnosis, risk assessment, and procedural planning.