EMBOLIZATION OF SPINAL DURAL ARTERIOVENOUS-FISTULAS - RESULTS AND FOLLOW-UP

OBJECTIVE: To evaluate the efficacy of embolization for spinal dural a rteriovenous fistulae (SDAVF). METHODS: We reviewed 49 cases of SDAVF treated by embolization. An acrylic material was used in all except tw o cases. Variable stiffness microcatheters were used in 38 cases. RESU LTS: ''Adequate'' initial treatment was performed in 39 cases (80%). A fter the introduction of variable stiffness microcatheters, the initia l success rate of embolization increased to 87% (33 of 38 cases). Eigh t patients underwent subsequent embolization for recurrence after ''ad equate'' embolization. Causes of recurrence were collateralization in five cases, development of new fistulae in one, and unknown in two. Tw o additional patients developed subsequent aggravation of the symptoms , probably caused by progressive venous thrombosis, that responded to heparinization. Ten cases were initially ''inadequately'' embolized. F ive of the 10 cases were treated before the introduction of variable s tiffness microcatheters. Each of three of the remaining five cases had a common trunk from which the feeder and a spinal cord artery arose. CONCLUSION: Embolization with an acrylic material should be the first choice of treatment for SDAVF, unless a spinal cord artery shares the same pedicle as the feeder of SDAVF. Subsequent aggravation of the sym ptoms after embolization can occur by various mechanisms. Therefore, p eriodic and long-term follow-up examinations are important.