gms | German Medical Science

Objective: Idiopathic spinal arachnoid cysts (ISACs) are rare and only small case-series have been described so far. Due to a variety of appearances, treatment of ISACs is controversial and often requires individual management. We therefore sought to perform a single center retrospective analysis of all surgically treated ISACs from 1997 until 2012.

Method: Symptoms, imaging, operative procedure and outcome of 27 ISACs were analyzed retrospectively. Patients with post-traumatic, post-inflammatory or post-operative arachnoid cysts were excluded. Post-operative and long-term clinical outcome was classified as “fair” (no improvement and/or complications), “good” (considerable improvement without complete resolution of symptoms) and “complete” (complete resolution of symptoms).

Results: 27 ISACs (13 male/14 female; age: 51±18 years) with a median follow-up of 65 months were analyzed. ISACs were predominantly located intradurally (89%), in the thoracic spine (59%) and dorsal to the spinal cord (78%), expanding on average over 3 vertebras. 4 patients showed multiple ISACs. Major presenting symptom was back pain (52%) followed by sensory loss and gait disturbance (44% each). Fenestration of the cyst was performed in 22 cases, complete resection in 3 and a combined procedure in 2 cases. 8 patients required secondary surgery (2x CSF leakage, 6x unsatisfactory outcome). A good early post-operative outcome was reached in 63%. Long-term outcome further improved in 11 patients. Half of the patients with secondary surgery showed no improvement. Long-term follow-up revealed good or complete outcome in over 80% of cases.

Conclusions: Our data suggests that satisfactory (good or complete) outcome can be achieved through surgical treatment in most cases. Repeated surgery can further improve postoperative symptoms. No correlation of patients outcome with size and localization of ISACs could be found. Therefore, cyst fenestration and an individually tailored approach seems the best management of symptomatic ISACs.