Abstract WP411: Anatomical Venous Variants and Physiological Adaptive Changes in Children With Cerebral Sinovenous Thrombosis

Abstract

Objective: Cerebral venous vessels a have unique morphology. No information is available regarding the presence of anomalous venous structure and related consequences in children. We aim to describe the frequency of anatomical variants (persistent fetal structures), and physiological changes (collateralization), in children with CSVT. We hypothesize that these variations impact in the re-distribution of venous drainage in the presence of stressors such as anemia or dehydration. Methods: We retrospectively reviewed children (1 month - 18 years), with CSVT over 5 years (Jan 2008 - Dec 2013). We excluded children with arterial ischemic stroke, trauma, compressive intracranial lesions and systemic venous hypertension. We reviewed for symptoms at presentation, risk factors, sinus involved, thrombus location, parenchymal lesions, antithrombotic therapy, outcome using the Paediatric Stroke Outcome Measure (PSOM) and recanalization rate at last follow-up. MRV/CTV reports were evaluated for anatomical variants and physiological changes in the venous systems. Results: Thirty-four children were identified. 17 boys (50%), with mean age at CSVT of 13.5 years (0.2 -17.6 years). 11 had anatomical variations (32%) vs. 23 (68%) with typical anatomy. These included 6 (54%) children with abnormal sinus morphology (hypoplasia/absence of a major dural sinus), 3 (27%) children with persistent fetal structures and 6 (54%) with prominent collateralization. Most of the cases had > 1 anatomical variant together. Signs of increased intracranial pressure were seen more frequently in children with anatomical variants 7(63%) than in those without variants 7(30%), although not statistically significant. 5 children (45%) with anatomical variations had brain parenchymal involvement vs. 5 (22%) with normal anatomy. Mean recanalization rate was the same between the two groups: 10(90%) at mean follow-up of 5.5mo (3 - 9mo) in the variant vs. 22(96%) at 4.2mo (1.5 - 9mo) in the normal anatomy group. Conclusion: The presence of anatomical variants in the cerebral venous structures may be associated with a more severe initial presentation in children with CSVT. Variant venous anatomy may be less efficient in compensating for the obstruction to venous outflow due to thrombosis.