The Importance of the Circle of Willis in Carotid Interventions Outcomes: A Real-Life Study.

Background: The main objective of this study is to evaluate and compare the outcomes regarding operative mortality rate, ipsilateral stroke, and overall survival rate among patients with internal carotid artery stenosis submitted to carotid endarterectomy (CEA) or stenting regarding the completeness of circle of Willis (CoW).

Methods: Prospective, consecutive cohort study of patients submitted to carotid interventions (CEA and carotid stenting: CAS) for internal carotid artery stenosis diagnosis evaluated according complete or incomplete CoW. The patients were divided into 2 groups: group I, the patients with complete CoW and group II, the patients with incomplete CoW, with the disruption of anterior and/or ipsilateral posterior circulation, regarding the ipsilateral significant carotid stenosis.

Results: Overall, 98 patients submitted to carotid intervention were evaluated. Two groups of patients were identified: group CoW complete with 54 patients and group CoW incomplete with 44 patients. Regarding the type of intervention, the prevalence of CAS in CoW complete group and CoW incomplete group were statistically similar (54.1% vs. 55.1%, P = 0.22). Notwithstanding, CEA was also statistically similar in CoW incomplete group and CoW complete group (44.2% vs. 45.9%, P = 0.22). The perioperative mortality rate was 2% in total cohort (2 patients), with no differences among CoW complete and incomplete groups (3.7% vs. 0%, P = 0.50, respectively). Furthermore, the incidence of postoperative stroke was 3.1% (asymptomatic 2%, symptomatic 1.1%), with no differences among CoW complete and incomplete groups (3.7% vs. 2.3%, P = 0.68, respectively). A univariate and multivariate linear regression showed that among the factors evaluated, only chronic kidney failure was related with hazard ratio = 1.89, P = 0.003, confidence interval 1.058-2.850.

Conclusions: The completeness of the CoW, independently of the type of carotid intervention (CEA and CAS), did not interfere in the results regarding postoperative outcomes for stroke and death. Chronic kidney disease was associated to increased risk of perioperative stroke.