Spinal extradural meningeal cysts: Long-term outcomes of a dural defect-oriented surgical strategy

Spinal extradural meningeal cysts are rare spinal lesions, and the optimal surgical strategy remains debated, particularly regarding the relative importance of complete cyst wall excision and closure of the dural communication. We retrospectively reviewed 10 patients (5 male and 5 female; mean age, 38.5 years) who underwent surgical treatment for Nabors Type IA spinal extradural meningeal cysts at a single institution between 1987 and 2023. The median symptom duration was 5.5 months. All lesions showed cerebrospinal fluid-equivalent signal intensity on magnetic resonance imaging. Surgical approaches included total or subtotal laminectomy, hemilaminectomy, and osteoplastic laminotomy. The mean clinical follow-up period was 121.6 months. Nine patients underwent partial cyst wall resection or fenestration with primary dural defect closure; among the seven patients in this group with available postoperative radiological follow-up, no radiological recurrence was observed. The single patient in whom primary dural closure was not achieved showed a persistent residual or recurrent cystic lesion on follow-up imaging but remained clinically improved. No neurological complications were observed. These findings suggest that identifying and closing the dural communication may be an important component of durable spinal extradural meningeal cyst management, whereas complete cyst wall excision may not always be necessary. Because this was a small retrospective case series with incomplete imaging follow-up in some patients, these findings should be interpreted as supportive clinical observations rather than definitive evidence of causality.