Accessory Brachial Artery Causing Delayed Vasospasm After Angiography: A Detailed Analysis of a Case Report.

Cerebral angiography remains the gold standard investigation for cerebrovascular disease. Transradial access is increasingly preferred over the transfemoral approach because it facilitates early ambulation and reduces complications at the access site. We report a woman in her 70s who developed delayed peripheral circulatory failure in the digital arteries following transradial cerebral angiography. After inserting a 4-French sheath into the conventional right radial artery, the catheter was advanced toward the subclavian artery but inadvertently entered a small accessory brachial artery with significant resistance, provoking severe vasospasm. The procedure was completed without incident after redirecting the catheter into the main brachial artery. Symptoms gradually appeared 24 hours after the procedure, and after 48 hours, the patient experienced burning pain, weakness, and pallor in her right hand. Angiography via the brachial artery demonstrated diffuse spasm of the radial artery, palmar arch, and digital arteries. Intra-arterial nitroglycerin quickly restored flow and alleviated symptoms. This case illustrates that inadvertent cannulation of an accessory brachial artery during transradial access can lead to delayed digital circulatory failure and that early intra-arterial vasodilator therapy is effective. Careful observation is necessary if such a catheter deviates into a small vessel with an anatomical anomaly, and spasm occurs.