Mechanisms of Procedural Stroke in CEA and CAS Evaluated

September 2, 2015—In the European Journal of Vascular and Endovascular Surgery (EJVES), Anne Huibers, MD, et al published findings from an analysis of the features of procedural strokes associated with carotid artery stenting (CAS) and carotid endarterectomy (CEA) within the International Carotid Stenting Study to identify the underlying pathophysiological mechanisms (2015;50:281–288). Understanding the mechanisms of procedural stroke is crucial to decreasing the procedural risk of carotid revascularization, noted the investigators. 

The study investigators randomly assigned patients with recently symptomatic carotid stenosis (N = 1,713) to CAS or CEA. Procedural strokes were classified by type (ischemic or hemorrhagic), time of onset (intraprocedural or after the procedure), side (ipsilateral or contralateral), severity (disabling or nondisabling), and patency of the treated artery. Only patients in whom the allocated treatment was initiated were included. The most likely pathophysiological mechanism was determined using the following classifications: carotid embolic, hemodynamic, thrombosis or occlusion of the revascularized carotid artery, hyperperfusion, cardioembolic, multiple, and undetermined.

As summarized in EJVES, the investigators found that procedural stroke occurred within 30 days of revascularization in 85 patients (CAS, 58 out of 791; CEA, 27 out of 819). Strokes were predominately ischemic (77; 56 CAS and 21 CEA), occurred after the procedure (57; 37 CAS and 20 CEA), ipsilateral to the treated artery (77; 52 CAS and 25 CEA), and nondisabling (47; 36 CAS and 11 CEA). 

The mechanisms of stroke were carotid embolic (14; 10 CAS and 4 CEA), hemodynamic (20; 15 CAS and 5 CEA), thrombosis or occlusion of the carotid artery (15; 11 CAS and 4 CEA), hyperperfusion (9; 3 CAS and 6 CEA), cardioembolic (5; 2 CAS and 3 CEA) and multiple causes (3 CAS). In 19 patients (14 CAS and 5 CEA), the cause of stroke remained undetermined.

The investigators' conclusion was that although the mechanisms of procedural stroke in both CAS and CEA are diverse, hemodynamic disturbance is an important factor. Careful attention to blood pressure control could lower the incidence of procedural stroke, advised the investigators in EJVES.