Transitional venous anomalies and DVAs draining brain AVMs: A single-institution case series and review of the literature

Objective: Developmental venous anomalies (DVAs) are typically benign lesions purely venous in nature. However, a subset of DVAs are either 1) associated with brain arteriovenous malformations (AVMs) or 2) demonstrate shunting themselves. The goal of this case series and literature review is to present clinical characteristics, management strategies and outcomes of this patient population. Methods: Consecutive patients with arteriovenous shunting DVAs or DVAs draining nidal-AVMs were retrospectively reviewed. Lesions were classified as transitional DVAs or AVM-associated DVAs. Variables studied included clinical presentation, location, size, venous drainage, and malformation architecture. Treatment outcomes were evaluated. Results: We identified 8 patients with transitional or AVM-associated DVAs from our institution. Six patients had unruptured lesions and two presented with hemorrhage. We classified 5 malformations as transitional DVAs and 3 as AVMs draining into DVAs. Three patients were conservatively managed, while 5 patients underwent treatment of the shunt by means of surgery (4) or radiosurgery (1). One patient suffered a right frontal venous infarct resulting in left sided weakness post-operatively. In the literature review we found 44 additional cases (Total = 30 transitional DVAs and 22 AVM-associated DVAs). Patients with transitional DVAs were more symptomatic than patients with AVM-associated DVAs (41.4% vs 22.2%). Permanent neurologic deficit following radiosurgical or microneurosurgical treatment of transitional DVAs was 28.6% compared to 16.7% for AVMs draining into DVAs. Conclusions: Transitional DVAs and AVMs draining into DVAs are rare lesions. Treatment is associated with substantial risk of venous infarct, particularly in situations where the draining vein is occluded.