Outcome from treatment for spinal arteriovenous malformation

Our knowledge of the outcome from treatment for spinal arteriovenous malfor mations (AVMs) is limited to a few small, anecdotal series and is thus far from complete. Furthermore, with the recent rapid evolution of our knowledg e of AVM pathology, many reported cases are difficult to place in the curre nt classification system. In general, outcome for the four classifications of AVMs are as follows: type I respond well to surgical disconnection of th e arteriovenous fistula if treatment is early; type II AVMs are currently b est treated by surgery but risks of a poor outcome need to be carefully con sidered; type III are only rarely treatable; type IVa and IVb are likely to respond well to surgery but our knowledge is limited; and type IVc are lik ely to fare poorly from surgery but should have a better outcome from endov ascular therapy.