title: Endoscopic fenestration of middle fossa arachnoid cysts: a technical description and case series.
abstract: BACKGROUND
  Arachnoid cysts are intra-arachnoidal cerebrospinal fluid collections most frequently seen in the middle cranial fossa. The optimal method of treatment for symptomatic arachnoid cysts remains controversial and includes cyst shunting, open craniotomy and endoscopic fenestration. All these techniques, however, have been associated with the development of postoperative subdural fluid collections. We describe a new endoscopic transcortical technique that attempts to avoid this complication.
  
  
  METHODS
  Six patients with middle cranial fossa arachnoid cysts were treated with endoscopic fenestration at our institution between January 2002 and December 2005. Three cases were approached directly through the cyst, while the other 3 were approached by passing the endoscope through the rim of adjacent cortex.
  
  
  RESULTS
  All six endoscopic fenestrations were successful in treating the arachnoid cysts. Among the 3 patients treated via a direct cyst entry, 2 cases developed significant subdural hygromas, 1 of which required aspiration. On the other hand, 1 of the 3 cases treated using a transcortical technique developed an insignificant postoperative extra-axial collection that resolved at 3 months without intervention.
  
  
  CONCLUSIONS
  Endoscopic fenestration is an effective treatment for symptomatic arachnoid cysts. Endoscopic fenestration via a transcortical approach attempts to minimize cerebrospinal fluid drainage into the subdural space, avoiding the development of significant postoperative extra-axial collections, while promoting flow into the basal cisterns.
authors.affiliation: Division of Pediatric Neurosurgery, Miami Children's Hospital, University of Miami, Miami, FL33136, USA.
authors.forename: Mohamed Samy A
authors.initials: MS
authors.lastname: Elhammady
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Bhatia
authors.forename: John
authors.initials: J
authors.lastname: Ragheb
mesh_terms: D016080:Arachnoid Cysts / Q000175:diagnosis / Q000601:surgery*; D002648:Child; D035301:Cranial Fossa, Middle / Q000473:pathology / Q000601:surgery; D004292:Dominance, Cerebral / Q000502:physiology; D019723:Endoscopes; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology; D012189:Retrospective Studies; D013353:Subdural Effusion / Q000175:diagnosis / Q000209:etiology; D014057:Tomography, X-Ray Computed