Arachnoidplasty for traumatic subdural hygroma associated with arachnoid cyst in the middle fossa. Case report.

A 5-year old boy presented with an arachnoid cyst in the middle cranial fossa with mild midline shift manifesting as headache and loss of activity. Computed tomography (CT) showed subdural hygroma. Burr-hole drainage was carried out and symptoms were improved postoperatively. However, recollection of subdural hygroma was found on follow-up CT 3 weeks after subdural drainage. He underwent craniotomy, and tearing of the outer wall of the arachnoid cyst was observed. The ruptured cyst wall was tightly closed by arachnoidplasty to prevent cerebrospinal fluid leakage. Arachnoidplasty was effective for traumatic subdural hygroma with arachnoid cyst for reconstruction.