Proposal of a Classification System of Cavernous Sinus Dural Arteriovenous Fistulas and Treatment Strategies Based on Angioarchitecture: A Cohort Study of 116 Patients.

Background: Cavernous sinus (CS) dural arteriovenous fistulas (DAVFs) are commonly treated by transvenous embolization, but the details of treatment need to be more clearly defined. We propose a classification of CS-DAVF that can contribute to formulating endovascular treatment process.

Methods: CS-DAVF was classified into seven categories based on the cumulative CS range and drainage patterns. CS-DAVF angioarchitecture, clinical characteristics, treatment strategies, and outcomes of CS-DAVF patients treated in our hospital from 2012 to 2021 were summarized and analyzed.

Results: Among the 116 patients with CS-DAVF: Type 1, 71 (61.2%); Type 2, 9 (7.8%); Type 3, 18 (15.5%); Type 4, 2 (1.7%); Type 5, 8 (6.9%); Type 6, 3 (2.6%); and Type 7, 5 (4.3%). Inter-CS or inferior petrosal sinus drainage was relatively rare in Types 1 and 6 (P < 0.001 and P < 0.001); basilar venous plexus drainage was more prevalent in Types 2, 5, and 7(P = 0.019). Inferior petrosal sinus occlusion was more commonly seen in Types 2, 3, and 5 (P = 0.005). The most frequent first symptoms and symptoms at admission in patients with CS-DAVF is ocular/orbital symptoms, occurring in 64 cases (55.2%) and 104 cases (89.7%), respectively. In this study, 108 patients (93.1%) underwent endovascular embolization. Among those who received endovascular embolization, 96 (88.9%) CS-DAVFs were treated via transvenous embolization. In long-term follow-up, 98 cases (84.5%) achieved cure, and 17 cases (14.7%) showed symptomatic improvement.

Conclusion: Our proposed classification system based on cumulative CS range and drainage patterns can assist in formulating treatment strategies for transvenous embolization.