Predictors of Complete Obliteration in Intracranial Dural Arteriovenous Fistulas

Introduction: Treatment modalities for intracranial dural arteriovenous fistulas (dAVFs) include endovascular embolization, microsurgical ligation, stereotactic radiosurgery, or combinations. Despite high treatment success rate, optimal patient selection criteria for intervention remains unclear. Recognition of successful treatment predictors will serve as a basis for developing a new scoring system that identifies patients likely to benefit from treatment.

Methods: This is a retrospective study derived from the Consortium for Dural Arteriovenous Fistula Outcomes Research database. Only patients who underwent treatment and with available outcome data were included. Patients were categorized based on complete dAVF obliteration. Parametric and nonparametric tests were used to compare baseline characteristics between groups. Logistic regression models were developed to identify independent predictors of complete dAVF obliteration.

Results: Of the 1,077 patients in the database, 880 were included. The mean age was 58 years (SD 14.2). The majority of dAVFs were unruptured (69%) and Borden class III (55%). Complete dAVF obliteration was achieved in 630 (71%) of cases. Univariable positive predictors of obliteration included no prior cranial surgery (CS) (96% vs. 93%, p=0.049), hemorrhagic presentation (53% vs. 18%, p< 0.001), no flow-related symptoms (54% vs. 32%, p< 0.001), mRS 3-5 at admission (12% vs. 6%, p=0.005), non-cavernous (89% vs. 83%, p=0.010) and non-transverse location (69% vs. 56%, p< 0.001), and Borden class III (63% vs. 36%, p< 0.001). Predictors of obliteration that remained significant in a stepwise hierarchical multivariable regression model were no prior CS (OR=2.45 [1.22-4.90]; p=0.011), no flow-related symptoms (OR=1.55 [1.05-2.28]; p=0.025), and Borden class III (OR=2.56 [1.60-4.09]; p< 0.001).

Conclusion : Among patients treated for dAVF, no prior CS, lack of flow-related symptoms, and Borden class III were independent predictors of complete obliteration. Borden class III as a predictor of obliteration likely reflects the curative goal in treating high-grade dAVFs. These findings serve as preliminary data in our prediction score development process.