Background: Guidelines recommend a 3-12 month duration of anticoagulation for cerebral venous thrombosis (CVT) and a repeat venogram at 3-6 months to assess recanalization. However, the relationship between recanalization and prognosis is not well defined. We performed a systematic review and meta-analysis to clarify the association between venous recanalization and prognosis in CVT.
Methods: We performed a literature search to identify all published studies that evaluated recanalization and prognosis in adult patients with a diagnosis of CVT treated with anticoagulation. Studies were identified using MEDLINE and EMBASE databases (1946 - 2017). Recanalization was ascertained by repeat venogram (CT, MR or conventional) and degree of recanalization was characterized as complete, partial or absent. Prognosis was defined using the modified Rankin Scale (mRS, 0-1 = excellent outcome).
Results: We found 675 articles and conference abstracts. Thirty-five were appropriate for full-text review and 11 had information regarding recanalization and clinical outcome, accounting for 450 subjects in total. All but one study had clinical and neuro-imaging reassessments within 12 months. Eighty-five percent had complete or partial recanalization within one year. Eighty-seven percent had an excellent outcome (mRS 0-1). As compared with complete or partial recanalization, those with no recanalization had a significantly increased odds of an mRS of 2-6 (OR 3.3, 95% CI 1.5 - 7.2, p=0.003). There was no significant difference in odds of worse prognosis for those with partial recanalization versus full recanaliation. No recanalization also carried a higher odds of CVT recurrence (OR 7.2, 95% CI 1.5 - 33, p=0.01) and chronic headache (OR 3.8, 95% CI 1.6 - 9.0, p=0.002).
Conclusion: Absence of recanalization is associated with a poorer prognosis in CVT patients. There does not appear to be a dose-response relationship with regards to degree of recanalization (partial versus complete) and prognosis.