Treatment strategy to maximize the treatment outcome of spinal dural arteriovenous fistula after initial endovascular embolization attempt at diagnostic angiography

Initial attempt of endovascular treatment (EVT) for spinal dural arteriovenous fistula (SDAVF) is preferred because of concurrent diagnosis and treatment. However, outcomes following further treatment with initial EVT are not well studied. We retrospectively reviewed 71 patients with SDAVF to evaluate treatment outcomes of SDAVF after an initial EVT attempt. Pretreatment and posttreatment functional states were assessed by the Aminoff-Logue scale (ALS). In the case of incomplete occlusion or recurrence, overall outcomes after further treatments were compared. Of the 71 patients, 56 underwent initial EVT. Complete occlusion was achieved by initial EVT in 37 of 56 patients (66.1%). Multiple feeders were more frequently observed in patients with incomplete occlusion than complete occlusion after initial EVT (73.7% vs. 27%, P < 0.001). Among 19 patients with incomplete occlusion upon initial EVT, 14 underwent additional surgery, 13 of whom (92.9%) obtained improved or stationary functional outcomes. Functional improvement was not observed in patients who had repeated EVT or follow-up without further treatment. Recurrence was observed in 8 of 37 patients with complete occlusion upon initial EVT. Additional surgery achieved improved functional outcomes in cases of incomplete occlusion of SDAVF after the initial EVT attempt or recurrence rather than repeated EVT or follow-up.