Likelihood of spontaneous closure of cavernous sinus dural arteriovenous fistulas based on clinical and radiological findings

Background: Cavernous sinus dural arteriovenous fistula (CSDAVF) is a rare condition that radiologists would encounter in their careers. We aim to describe the clinical and radiological characteristics of this condition, and to provide a management workflow. Methods: In our retrospective study, we studied 27 patients with CSDAVF from January 2007 to August 2020. Patients with direct cavernous sinus AVFs and patients with incomplete date were excluded. Clinical and radiological data were collected and analyzed. Results: Fourteen patients were conservatively treated with spontaneous resolution while 13 patients had endovascular intervention performed. In the intervention group, seven patients had intra-cranial reflux seen on radiological imaging and six patients had clinical deterioration, hence requiring intervention. Clinically, among our patients, 21 had proptosis, 20 had conjunctiva hyperaemia, 18 had extraocular movement limitation, 13 had raised intraocular pressure, 11 had chemosis, ten had ocular pain, nine had ocular bruit, eight had headache and six had worsening visual acuity. Radiologically, a concurrence was seen between superior ophthalmic vein thrombosis and spontaneous resolution of the CSDAVF, as compared to those who underwent intervention. A paradoxical increase of ocular symptoms was seen despite a decrease of flow or stagnation of contrast in radiological imaging of CSDAVF. Conclusions: In our study, 52% of CSDAVF closed spontaneously. As deterioration of ocular symptoms in patients with CSDAVF might also reflect spontaneous progressive occlusion, it warrants dynamic vascular imaging to check the status of venous outflow. Patients with CSDAVF with corticovenous reflux or deterioration of visual acuity need more urgent (endovascular) treatment.