S1-06 SESSION 1: NEUROSURGERY ABNORMAL VENOUS DRAINAGE IN COMPLEX CRANIOSYNOSTOSIS MAY CAUSE VENTRICULOMEGALY

Introduction: The management of complex forms of craniosynostosis depends on several interdependent factors, including progressive suture closure, raised intracranial pressure, obstruction of the CSF flow and venous obstruction. Abnormal venous drainage has been reported in these patients, but its anatomical description and evolution is not well described, in particular the risk for ventriculomegaly. The aim of this study was to identify the pattern of the collateral venous network in faciocraniosynostosis and to correlate its evolution with the surgical strategy. Methods: Between 2000 and 2018, among 248 patients managed for complex craniosynostosis managed at Necker - Enfants Malades Hospital, a preliminary group of 21 patients underwent a sequential MRI with 3D T2 acquisitions and venous imaging, including 2D TOF imaging, InhanceÓ(GE, Texas, USA) imaging or 3D gadolinium enhanced T1 imaging. The patients were analyzed according their syndrome (Crouzon, Pfeiffer, Apert). For each patient, the effect of surgery on venous development and ventriculomegaly were assessed. In these 21 patients, the mean age at the first MRI before any surgery was 10 months. Results: 33% of the patients carried bilateral bony stenosis of the jugular foramina. The left jugular bulb was never visualized, and the right jugular bulb was visualized in 17% of the patients. The collateral venous network developed based on three anatomical venous cranial base systems: the anterior system (ethmoidal-frontal-ophtalmic veins, 83% of the cases), the middle system (pterygoid plexus, 92% of the cases) and the posterior system (torcular-mastoid-condylar emissary veins, 75% of the cases). A generalized logistic regression model suggested that ventriculomegaly correlated with bilateral bony stenosis (p=0.03) and the absence of right jugular bulb (p=0.05) on venous imaging. The analysis of venous network distribution in each syndrome and the result and impact of surgery on venous system is currently in progress. Conclusion: Patients with faciocraniosynostosis present various degree of stenosis of the jugular bulbs with subsequent development of a collateral venous network. This network runs through three anatomical cranial base systems. Our data suggest that ventriculomegaly develops in case of true bilateral obstruction of the jugular bulbs.