Abstract 17923: Acute Limb Ischemia Due to Dissection and Thrombosis of Anomalous Right Subclavian Artery: A Rare Complication of Trans-Radial PCI

Introduction: Right subclavian artery (RSA) normally originates from brachiocephalic artery, but in 0.4-1.8% of the general population it may arise directly from the aortic arch distal to the left subclavian artery. We present a case of acute limb ischemia due to dissection and thrombosis of anomalous right subclavian artery (ARSA) following transradial PCI.

Case: A 60-year-old female presented with anterior STEMI. Coronary angiogram was performed via right transradial approach. During the procedure the aortic arch was noted to be exceedingly tortuous and coronary artery catheterization was difficult. Post-procedure, patient reported right arm pain. Her right hand was cold with bluish discoloration, nonpalpable right radial, ulnar and brachial artery pulses which prompted a CTA of the chest and right upper extremity. Imaging revealed ARSA with dissection and thrombosis of the RSA extending to mid-brachial artery and absent opacification of radial/ulnar arteries. The patient underwent right brachial artery cutdown, axillary artery thrombectomy and stenting of ARSA dissection. Post procedure, her pulses were palpable with triphasic doppler signals in the radial and ulnar artery. Four months later, surveillance CTA of chest showed patent stent without additional evidence of dissection (Figure 1).

Discussion: ARSA is a rare anatomical variation of the origin of the RSA but also the most common abnormality of the aortic arch. ARSA anomaly is often asymptomatic, but approximately 10% is associated with tracheo-esophageal symptoms; the most frequent among them is dysphagia. Only 60% of coronary procedures using transradial approach are successful in the presence of ARSA. This congenital variant makes it difficult to approach the ascending aorta by the right transradial route, as it requires the catheter to curve back to reach the aortic root. Prompt recognition of this anomaly during the procedure and alternate access routes can avoid these severe complications.