Acute thromboembolic events during carotid artery angioplasty and stenting: Etiology and a technique of neurorescue

Purpose: To review the protected carotid stenting experience at two major referral centers to evaluate the frequency of clinically significant intraprocedural thromboembolic events, use of neurorescue techniques, and ultimate clinical outcomes. Methods: A retrospective review was conducted of 254 cases of protected transfemoral carotid stenting performed at the Washington University-Barnes Hospital and The Fleni Institute of Buenos Aires in a 6-year period. Medical records of patients with periprocedural thromboembolic events were reviewed to determine the type of complication, method of treatment, and outcome. Results: Among the 254 cases in which a carotid protection device was used, 2 (0.79%) episodes of witnessed, symptomatic thromboembolism occurred. Both patients suffered thromboembolic occlusion of the M1 branch of the middle cerebral artery (MCA) immediately following crossing of the internal carotid lesion with the protection device. Neurological symptoms consisted of agitation, aphasia, and hemiplegia in both patients. After rapid stent deployment across the carotid lesion, the MCA was cannulated and the occlusion treated with balloon angioplasty. This was followed by selective intra-arterial delivery of urokinase and intravenous abciximab. These maneuvers resulted in excellent restoration of blood flow in the MCA and its branches. With the exception of minor word-finding difficulties in one, both patients demonstrated full neurological recovery within the perioperative period. Conclusions: In our experience, intraprocedural thromboembolic events occur despite the use of cerebral protection devices, but are rare. Notably these complications appeared to occur at the time of lesion crossing by distal cerebral protection devices. These thromboembolic events can be successfully treated if the complication is rapidly identified and the physician is adequately prepared and proficient in neurorescue techniques.