Recanalization in Cerebral Venous Thrombosis: A Systematic Review and Meta-Analysis

Background and Purpose The role of recanalization of the occluded dural sinus or vein in the outcome of patients with cerebral venous thrombosis (CVT) is not established. We aimed to systematically review, in patients with CVT, (1) the recanalization rate and its association with (2) clinical outcome and (3) CVT recurrence. Methods Systematic search in MEDLINE (Medical Literature Analysis and Retrieval System Online), Cochrane Library, and clinicaltrials.gov (inception to September 2017). We considered cohort studies reporting the recanalization rate in adult patients with CVT treated with anticoagulation. Reported rates of venous recanalization at the last follow-up, functional outcome defined using the modified Rankin scale at last follow-up dichotomized for favorable (0-1) and unfavorable (2-6) outcome, and recurrence rate of CVT according to recanalization status were extracted independently by 2 authors. Meta-analyses of proportions were performed using Freeman-Tukey double arcsine transformation. Functional outcomes according to the recanalization status were compared using meta-analysis and ordinal logistic regression. We conducted sensitivity analyses for time to assessment of recanalization and study quality. Results Four hundred sixty-eight studies were identified, and 19 studies were included. (1) We found report of 694 patients with recanalization in the follow-up among 818 cases of CVT. The overall pooled proportion of patients achieving recanalization was 85% (95% confidence interval, 80-89; I-2=58%). In studies with higher methodological quality, the recanalization rate was 77% (95% confidence interval, 70-82; I-2=0%). (2) There was a significant increase in the chance of favorable outcome (modified Rankin scale, 0-1) in patients with recanalization with a pooled odds ratio of 3.3 (95% confidence interval, 1.2-8.9; I-2=32%) in the random effects meta-analysis and a common odds ratio of 3.3 (95% confidence interval, 1.7-6.3) in the ordinal logistic regression. (3) Data on CVT recurrence according to recanalization was scarce. Conclusions The overall rate of recanalization in patients receiving anticoagulation was 85%, but exclusion of severe patients from follow-up imaging is a plausible source of bias. Lack of venous recanalization was associated with worse clinical outcome.