MATERIAL and METHODS: Sixty-six patients who underwent IAC surgery in our department between 2010 and 2020 were studied retrospectively. Based on the surgical technique, clinical and volumetric changes, postoperative complications, recurrence rates, and length of hospital stay were statistically compared.

RESULTS: Microsurgical fenestration (MF) was performed on 32 (48.5%) patients, endoscopic fenestration (EF) on 17 patients, cystoperitoneal shunt (CPS) on 11 patients, and EF + CPS in six patients. The mean IAC volume change rate was 68.54 mL, and the mean cyst volume change rate was 40.68%. The MF technique produces a significantly greater mean cyst volume change than the EF technique. The mean volume change in sylvian IAC is 4.8 times greater than in posterior fossa IAC, a significant difference. The mean cyst volume change is four times greater in patients with skull deformity than in patients with balance loss, and this difference is statistically significant. In patients with cranial deformity, the mean cyst volume change is 2.6 times greater than in patients with neurological dysfunction. This difference is also statistically significant. The volume of IAC decreased more in patients with postoperative complications, with a significant difference between the postoperative complication and the change in IAC volume.

CONCLUSION: MF can achieve better volumetric reduction in IAC, particularly in patients with sylvian arachnoid cysts. However, more volumetric reduction increases the risk of postoperative complications. Keywords : Arachnoid cyst, Endoscopy, Fenestration, Microsurgery, Volume