Surgical treatment of spinal arachnoid web: Report of two cases and literature review.

Background: Arachnoid webs (AWs) can cause cord compression and syringomyelia in the thoracic spine. Here, we describe two patients who underwent operative treatment for AW and reviewed the literature.

Case Description: Two patients underwent surgical treatment for thoracic AW. Both presented with spastic gait and numbness in the lower extremities. On MR, these lesions exhibited the "scalpel" sign (i.e. due to the accumulation of cerebrospinal fluid on the dorsal aspect of the spinal cord). Operative intervention, consisting of fenestration and web resection, resulted in symptom resolution.

Conclusion: Thoracic AWs are rare lesions that should be considered among the differential diagnosis of spinal compressive syndromes. Surgical fenestration and resection of the AW correct the flow dynamics allowing for full symptoms resolution.