Endoscopic and Microsurgical Treatment of Sylvian Fissure Arachnoid Cysts—Clinical and Radiological Outcome

ObjectiveA Sylvian fissure arachnoid cyst (SAC) is a well-recognized location for an intracranial arachnoid cyst in the pediatric population. For those cysts, which can rupture and be accompanied by a subdural hygroma or hematoma, several treatment modalities have been reported. We report clinical and radiological outcome of fenestration of these cysts by either endoscopy or microsurgery.MethodsA retrospective review of the database of operative procedures revealed 24 procedures (20 endoscopic and 4 microsurgical procedures) to fenestrate a SAC at university hospitals in Berlin, Germany and Tokyo, Japan.ResultsWith the applied technique, a reduction of SAC volume of more than 10% was achieved in 83.3% of all patients. The median volume of SACs (n = 24) was significantly reduced from 83.5 mL (range 21–509 mL) preoperatively to 45.5 mL (range 8.4–261 mL; P < 0.01) after 3.5 months and to 29.0 mL (range 0–266 mL; P < 0.01) after 15 months. In children (n = 8) with a ruptured SAC the combined extraaxial volume of a SAC and accompanying hygroma/hematoma was reduced from 166 mL (range 111–291 mL) before surgery to 127 mL (range 87–329 mL) after 2 months and to 77 mL (range 25–140 mL; P < 0.05) after 11 months. Acute clinical symptoms were generally resolved postoperatively; headaches were resolved or improved in 75%. A significant association of resolution or improvement of headaches and volume reduction was demonstrated.ConclusionsThe study demonstrated efficacy in a predominantly endoscopically treated patient cohort with Sylvian fissure arachnoid cysts, as indicated by improvement of clinical symptoms and diminished radiological SAC volume after treatment.