gms | German Medical Science

Objective: Spinal dural arteriovenous fistula (SDAVF) is a rare diagnosis and often misdiagnosed due to a long history of varying clinical symptoms. Although the underlying pathology of a single vessel malformation is well understood, diagnosis and therapy still calls for an experienced interdisciplinary approach.

Methods: Since 1986 86 patients were treated in our institution. Clinical symptoms, preoperative myelography, MRI and angiography were analyzed to define the characteristic features of SDAVF. 12 months follow-up included clinical status, MRI and angiography.

Results: Demographic data of the patient group showed male predominance (m/f ratio of 8/2) with an average of 60 years. Medium time between initial symptom and correct diagnosis were 18 months. Subarachnoid or intraparenchymatous hemorrhage was extremely rare. Paresis, sensory loss, urinary incontinence, bowel and gait disturbances occurred in over 80% of patients. Back pain was less frequent (55%) and not specific. Thoracic location (70%) of the fistula was followed by the lumbar (19%) site. Angiography was most sensitive in diagnosing dilated perimedullary veins (100%). Detection of congestive edema was most sensitive in MRI (100%). Myelon distension was less frequently seen on MRI (75%). Endovascular occlusion by histoacrylate or ethibloc was performed in half of the patients, surgical resection was done in 34% of patients. In 17% embolization was incomplete and followed by surgical resection. Clinical symptoms improved in 52%, no change was seen in 38% and worsening in 10%. On control MRI a suspicious SDAVF pathology was seen in 34 cases Angiography confirmed late recurrency in 19 patients who were treated endovascularly.

Conclusions: Severe neurological symptoms, including bowel and gait disturbances are rarely improved by therapy and an early diagnosis helps to improve outcome. SDAVF therapy should follow a clear strategy beginning with spinal angiography and one attempt at endovascular occlusion. If that cannot be easily accomplished, surgery with intradural interruption of the draining vein has to follow. We found coil-marking to be helpful in localizing the fistula intraoperatively so that limited hemilaminectomy remains sufficient for surgical exposure. Follow-up investigation by angiography is necessary to exclude late recurrences and to ensure the longlasting success of the therapeutic procedure.