Impact of surgical strategy on functional outcome and recurrence in spinal arachnoid cysts.

BACKGROUND: Spinal arachnoid cysts (SACs) are rare benign lesions that account for 1-3% of spinal space-occupying lesions. This study evaluated clinical/radiological characteristics, surgical outcomes, and predictors of functional recovery, recurrence, and complications in SAC surgery. MATERIALS AND METHODS: We retrospectively reviewed 41 patients who underwent microsurgical treatment for histologically confirmed SACs (January 2013-May 2023), analysing demographics, clinical presentation, imaging, surgical technique, functional outcomes, postoperative complications and recurrence. RESULTS: The study included 21 males and 20 females (mean age 30.5 years). Motor weakness was the most common presenting symptom (73.2%), followed by spasticity (51.2%) and pain/sensory symptoms (43.9% each). Most cysts were solitary (97.6%), dorsally located (78%), spanning a mean of 5.4 vertebral levels; extradural type-IA cysts were most common (56.1%), predominantly in the thoracic spine. Cyst excision was the primary procedure (63.4%), followed by marsupialization (19.5%) and fenestration (12.2%). Mean MMS score improved significantly from 1.63 preoperatively to 1.13 at final follow-up (p = 0.003), with 89.7% achieving MMS Grade 1. Excision yielded significant functional improvement (p = 0.031); fenestration and marsupialization also showed favorable outcomes, with all fenestration patients reaching Grade 1. Preoperative MMS score was the sole significant predictor of outcome. Complications occurred in 9.8% of patients; recurrence rate was 7.3%, significantly higher for cysts spanning ≥ 7 vertebral levels. CONCLUSIONS: Microsurgical SAC treatment achieves significant functional improvement with 9.8% complication and 7.3% recurrence rates. Management should be tailored to cyst type, location, and extent, with early intervention and careful planning for larger, recurrence-prone cysts.