Drainage outflow restriction as a parameter associated with cortical venous reflux in craniofacial arteriovenous malformations with cavernous sinus drainage

Purpose: Craniofacial arteriovenous malformations (CF-AVMs) are locally aggressive extracranial lesions. When CF-AVMs involve cavernous sinus (CS) as their draining vein, they represent a special subgroup which may interfere intracranial venous system. In this study, we aimed to analyze the venous drainage patterns of CF-AVMs with CS drainage and to demonstrate how it affected our treatment strategy. Methods: Cases of CF-AVMs associated with CS drainage were collected from a prospectively collected database of patients with CF-AVMs who underwent endovascular treatment from September 2016 to March 2018. Clinical data and angioarchitectural findings were analyzed. Factors associated with the presence of venous reflux (cortical venous reflux (CVR) or dural sinus reflux (DSR)) were analyzed. Results: Fifteen CF-AVM patients associated with CS drainage were analyzed. Three cases of venous reflux from the CS were identified (CVR, 2; DSR, 1). Lesions with unilateral venous drainage, ≤ 2 draining veins, and the absence of antegrade CS outflow were more likely to develop venous reflux from the CS. We successfully performed additional trans-venous coil embolization of the superior ophthalmic vein in two patients with malformations associated with venous reflux to close this venous connection to the CS. Conclusion: CF-AVMs associated with CS drainage confer an increased risk of CVR and DSR, especially in cases where the drainage outflow is restricted. Identification of this venous angioarchitecture is essential in the evaluation and treatment planning of CF-AVMs.