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

Abstract

A 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. A 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. With 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. The 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.