Observation Versus Intervention for Low-Grade Intracranial Dural Arteriovenous Fistulas
Authors: Chen Ching-Jen , Buell Thomas J , Ding Dale , Guniganti Ridhima , Kansagra Akash P , Lanzino Giuseppe , Brinjikji Waleed , Kim Louis , Levitt Michael R , Abecassis Isaac Josh , Bulters Diederik , Durnford Andrew , Fox W Christopher , Polifka Adam J , Gross Bradley A , Hayakawa Minako , Derdeyn Colin P , Samaniego Edgar A , Amin-Hanjani Sepideh , Alaraj Ali , Kwasnicki Amanda , van Dijk J Marc C , Potgieser Adriaan R E , Starke Robert M , Chen Stephanie , Satomi Junichiro , Tada Yoshiteru , Abla Adib , Phelps Ryan R L , Du Rose , Lai Rosalind , Zipfel Gregory J , Sheehan Jason P ,   Consortium for Dural Arteriovenous Fistula Outcomes Research, Zipfel Gregory J , Kansagra Akash P , Guniganti Ridhima , Piccirillo Jay F , Raman Hari , Lipsey Kim , Lanzino Giuseppe , Vine Roanna , Giordan Enrico , Brinjikji Waleed , Cloft Harry J , Kallmes David F , Pollock Bruce E , Link Michael J , Sheehan Jason , Chen Ching-Jen , Rao Mohana Patibandla , Ding Dale , Buell Thomas , Paisan Gabriella , Kim Louis , 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 , Samir Sur , Chen Stephanie , Satomi Junichiro , Tada Yoshiteru , Kanematsu Yasuhisa , Yamamoto Nobuaki , Kinouchi Tomoya , Korai Masaaki , Yamaguchi Izumi , Yamamoto Yuki , Abla Adib , Winkler Ethan , Phelps Ryan , Lawton Michael , Rutkowski Martin , Du Rose , Lai Rosalind , Sultan M Ali Aziz , Patel Nirav , Frerichs Kai U 
Published: January 2021

Abstract

BACKGROUND
Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial.

OBJECTIVE
To compare the outcomes of observation versus intervention for low-grade dAVFs.

METHODS
We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up.

RESULTS
The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort (P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively.

CONCLUSION
Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.