Rare association between spinal dural arteriovenous fistulas and dysraphisms: Report of two cases and review of the literature with a focus on pitfalls in diagnosis and treatment.

Spinal vascular malformations are uncommon yet important spinal pathologies commonly classified in congenital and acquired lesions. Spinal lipomas consist of three subtypes: intramedullary lipomas, lipomyelo(meningo)celes and lipomas of the filum. Although the association of spinal arteriovenous malformations (AVM) with other congenital anomalies is well known, the coexistence of dural arteriovenous fistulas (AVF) and tethered spinal cord is exceptionally rare and only eight cases have been reported. We present two cases from our institution and speculate on the possible origin of such a rare but insidious association. We review the current literature with a focus on possible pitfalls in diagnosis and treatment.