Multiple spinal arteriovenous fistulas: A case-based review.

The occurrence of multiple spinal dural arteriovenous fistulas (AVFs) is rare. The majority of cases reported are synchronous and the lesions are mainly found at different spinal levels. Metachronous AVFs have been defined as lesions that manifest in a temporal sequence after treatment of a first AVF. In this report, we present two distinct cases of multiple spinal AVFs. Also, we review the main features of the cases previously reported, with emphasis on the proposed theories for the origin of multiple AVFs. In patients with failure to improve after treatment of a spinal DAVF, a whole-spine angiographic examination is mandatory, not only to ascertain the complete closure of the treated fistula, but also to look for a possible second lesion at a different spinal level.