Management of spinal dural arteriovenous fistulae using an interdisciplinary neuroradiological/neurosurgical approach: experience with 47 cases.

OBJECTIVE: Spinal dural arteriovenous fistulae (SDAVFs) are frequently diagnosed after unacceptable delays and are therefore treated at a disadvantageously advanced stage. There is controversy regarding their treatment and the respective roles of interventional neuroradiologists and neurosurgeons. We present our series of 47 patients to illustrate the necessity for early treatment and the value of an interdisciplinary approach.
METHODS: All patients exhibited suspicious magnetic resonance imaging and/or myelographic findings. Subsequent spinal angiography revealed the SDAVFs. Twelve patients were treated primarily by surgical interruption of the arterialized intradural draining vein, and eight patients underwent surgery after unsuccessful embolization. Twelve patients were surgically treated several months after embolization because of the recruitment of collateral vessels. Definitive embolization was achieved for 15 patients. All patients were monitored with magnetic resonance imaging and at least one control angiographic examination. Follow-up periods ranged from 2 months to 8 years.
RESULTS: There was an obvious male prevalence, with 35 male and 12 female patients. Only six of the patients were less than 50 years of age. The SDAVFs were found twice as often on the left side, compared with the right. A total of 85% of the SDAVFs were located between T2 and L2. Presenting signs were most often progressive paraparesis, with 66% of the patients exhibiting progression to a condition in which they could not walk without support or were confined to a wheelchair. For 50% of the patients, the time at which the correct diagnosis was established was more than 15 months after the onset of the first symptoms. After treatment, 18 patients showed improvement (38%), the conditions of 26 patients (55%) were unchanged (without further deterioration), and the conditions of three patients (6%) had deteriorated.
CONCLUSION: Attempts at embolization should be made at the time of angiography, because no adverse effects were recorded in our series and there was a 30% chance of the patients being cured by that modality alone. Even if recanalization occurs, the internal labeling of a feeding vessel with radio-opaque embolization material allows exact intraoperative fluorographic localization of the origin of the draining vein, facilitating minimally invasive surgical exposure.