Surgical outcomes for spinal arachnoid cysts and webs: a case series

Spinal arachnoid cysts (SAC) and spinal arachnoid webs (SAW) are intradural pathologies, often presenting with pain and/or myelopathic symptoms. Reports on postoperative outcomes for SAC and SAW are scarce. This study aims to assess the surgical outcomes of SAC and SAW.

Patients who underwent surgical treatment for SAC or SAW at our institution between 2011 and 2023 were retrospectively reviewed. Demographic data, radiological findings, surgical management, and clinical outcomes were evaluated using the modified McCormick (mMC) scale. Outcomes were categorized as "favorable" (mMC I-II) or "unfavorable" (mMC III-V).

A total of 35 patients (29 SAC, 6 SAW) were analyzed. Mean age was 50.9 (SD ± 9.8) years. Males comprised 70.3% of cases (SAC: 64.5%, SAW: 100%). Most common symptoms were local or radiating pain (SAC 77.4%; SAW 100%), gait-disturbance (SAC 45.2%; SAW 16.7%), sensory-deficits (SAC 32.3%; SAW 66.7%) and impaired motor function (SAC 20%; SAW 16.7%). Median preoperative mMC was 2 in both groups (SAC IQR: 1; SAW IQR: 1). Median postoperative mMC was 1 in both groups (SAC CI 1.07-1.34; SAW CI 0.74-1.60). Favorable outcome (postoperative mMC I-II) was achieved in 26 SAC patients (90%) and 5 SAW patients (83%) respectively. Surgical complications occurred in 14.7%, all in the SAC group, without lasting deficits.

Surgical treatment for SAC and SAW appears to have an overall favorable outcome, though larger cohort analyses are needed. Surgery should be considered in symptomatic patients.