Dural arteriovenous fistulas without cortical venous drainage: presentation, treatment, and outcomes
Authors: Samaniego Edgar A. , Roa Jorge A. , Hayakawa Minako , Chen Ching-Jen , Sheehan Jason P. , Kim Louis J. , Abecassis Isaac Josh , Levitt Michael R. , Guniganti Ridhima , Kansagra Akash P. , Lanzino Giuseppe , Giordan Enrico , Brinjikji Waleed , Bulters Diederik , Durnford Andrew , Fox W. Christopher , Polifka Adam J. , Gross Bradley A. , Amin-Hanjani Sepideh , Alaraj Ali , Kwasnicki Amanda , Starke Robert M. , Sur Samir , van Dijk J. Marc C. , Potgieser Adriaan R. E. , Satomi Junichiro , Tada Yoshiteru , Abla Adib , Winkler Ethan , Du Rose , Lai Pui Man Rosalind , Zipfel Gregory J. , Derdeyn Colin P. , _ _ , _ _ , Zipfel Gregory J. , Kansagra Akash P. , Guniganti Ridhima , Piccirillo Jay F. , Raman Hari , Lipsey Kim , Lanzino Giuseppe , Giordan Enrico , Brinjikji Waleed , Vine Roanna , Cloft Harry J. , Kallmes David F. , Pollock Bruce E. , Link Michael J. , Sheehan Jason , Chen Ching-Jen , Patibandla Mohana Rao , Ding Dale , Buell Thomas , Paisan Gabriella , Kim Louis J. , Levitt Michael R. , Abecassis Isaac Josh , Meyer R. Michael , Kelly Cory , Bulters Diederik , Durnford Andrew , Duffill Jonathan , Ditchfield Adam , Millar John , Macdonald Jason , Fox W. Christopher , Polifka Adam J. , Laurent Dimitri , Hoh Brian , Smith Jessica , Lockerman Ashley , Gross Bradley A. , Lunsford L. Dade , Jankowitz Brian T. , Hayakawa Minako , Derdeyn Colin P. , Samaniego Edgar A. , Gutierrez Santiago Ortega , Hasan David , Roa Jorge A. , Rossen James , Guerrero Waldo , McGruder Allen , Amin-Hanjani Sepideh , Alaraj Ali , Kwasnicki Amanda , Charbel Fady T. , Aletich Victor A. , Rose-Finnell Linda , van Dijk J. Marc C. , Potgieser Adriaan R. E. , Starke Robert M. , Peterson Eric C. , Yavagal Dileep R. , Sur Samir , Chen Stephanie H. , Satomi Junichiro , Tada Yoshiteru , Kanematsu Yasuhisa , Yamamoto Nobuaki , Kinouchi Tomoya , Korai Masaaki , Yamaguchi Izumi , Yamamoto Yuki , Abla Adib , Winkler Ethan , Phelps Ryan R. L. , Lawton Michael , Rutkowski Martin , Du Rose , Lai Pui Man Rosalind , Aziz-Sultan M. Ali , Patel Nirav , Frerichs Kai U. 
Published: September 2021

OBJECTIVE
Current evidence suggests that intracranial dural arteriovenous fistulas (dAVFs) without cortical venous drainage (CVD) have a benign clinical course. However, no large study has evaluated the safety and efficacy of current treatments and their impact over the natural history of dAVFs without CVD.

METHODS
The authors conducted an analysis of the retrospectively collected multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database. Patient demographics and presenting symptoms, angiographic features of the dAVFs, and treatment outcomes of patients with Borden type I dAVFs were reviewed. Clinical and radiological follow-up information was assessed to determine rates of new intracranial hemorrhage (ICH) or nonhemorrhagic neurological deficit (NHND), worsening of venous hyperdynamic symptoms (VHSs), angiographic recurrence, and progression or spontaneous regression of dAVFs over time.

RESULTS
A total of 342 patients/Borden type I dAVFs were identified. The mean patient age was 58.1 ± 15.6 years, and 62% were women. The mean follow-up time was 37.7 ± 54.3 months. Of 230 (67.3%) treated dAVFs, 178 (77%) underwent mainly endovascular embolization, 11 (4.7%) radiosurgery alone, and 4 (1.7%) open surgery as the primary modality. After the first embolization, most dAVFs (47.2%) achieved only partial reduction in early venous filling. Multiple complementary interventions increased complete obliteration rates from 37.9% after first embolization to 46.7% after two or more embolizations, and 55.2% after combined radiosurgery and open surgery. Immediate postprocedural complications occurred in 35 dAVFs (15.2%) and 6 (2.6%) with permanent sequelae. Of 127 completely obliterated dAVFs by any therapeutic modality, 2 (1.6%) showed angiographic recurrence/recanalization at a mean of 34.2 months after treatment. Progression to Borden-Shucart type II or III was documented in 2.2% of patients and subsequent development of a new dAVF in 1.6%. Partial spontaneous regression was found in 22 (21.4%) of 103 nontreated dAVFs. Multivariate Cox regression analysis demonstrated that older age, NHND, or severe venous-hyperdynamic symptoms at presentation and infratentorial location were associated with worse prognosis. Kaplan-Meier curves showed no significant difference for stable/improved symptoms survival probability in treated versus nontreated dAVFs. However, estimated survival times showed better trends for treated dAVFs compared with nontreated dAVFs (288.1 months vs 151.1 months, log-rank p = 0.28). This difference was statistically significant for treated dAVFs with 100% occlusion (394 months, log-rank p < 0.001).

CONCLUSIONS
Current therapeutic modalities for management of dAVFs without CVD may provide better symptom control when complete angiographic occlusion is achieved.