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

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.

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.

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.

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.