title: Evaluation of the management of arachnoid cyst of the posterior fossa in pediatric population: experience over 27 years.
abstract: BACKGROUND
  The necessity of surgical treatment of the arachnoid cyst in general and posterior fossa arachnoid cyst (PFAC) in particular is sometimes controversial. Surgery is warranted in symptomatic patients. In this study, we evaluated our experience throughout 27 years in the management of patients with PFAC.
  
  
  METHODS
  The study was designed with special emphasis on clinical features, surgery, and outcome. We investigated a total of 112 arachnoid cysts. Of them, 23 patients were symptomatic for PFAC. We assessed clinical characteristic and outcome for all patients. We obtained information from medical records and outpatient charts on age, sex, presenting symptoms, associated abnormalities, psychomotor status, modality of treatment, complications and follow-up in 23 patients (9 boys, 14 girls, ages 1 day-6 years) who had been admitted for evaluation and treatment of PFAC at Kobe Children's Hospital between 1978 and 2004.
  
  
  RESULTS
  The mean follow-up period was 93 months (range 5-313 months). More than half of the patients had a history of increased head size and signs of intracranial pressure as presenting symptoms. One-third of the patients had associated abnormalities and six patients (26%) presented hydrocephalus. Computed tomography cisternography displayed delayed filling of the cyst in 11 patients (48%). All patients were treated surgically; the total number of surgical procedures was 55 with a surgical rate of 2.4 per patients. The marsupialization and marsupialization with cyst-peritoneal (C-P) shunt were the most common open surgical procedure in 14 and 5 patients, respectively. Endoscopic cysternostomy was performed in three patients. In our series, 25 (45%) of 55 surgical procedures included shunt malfunction and removal. The marsupialization of the cyst wall was successful in 9 of 14 operated patients (64%); the other five patients needed additional C-P or ventriculoperitoneal (V-P) shunt. Marsupialization with cyst-peritoneal shunt was successful in only one of five patients (20%), and for the other four patients, additional C-P or V-P shunt was necessary. No mortality is reported. Eight patients presented minor surgical morbidities that were resolved conservatively.
  
  
  CONCLUSIONS
  The relatively good results using marsupialization or endoscopic cisternostomy as surgical procedure and the high incidence of shunt malfunction buttresses our use of both operations as a first-line surgery at present. Surgical procedure that does not include shunting decreases the ratio of recurrent operation because this kind of complication develops over time and should be consider as a second-line procedure.
authors.affiliation: Department of Neurosurgery, Hospital Central Instituto de Prevision Social, Av. Sacramento y Manuel Peña, Asuncion, Paraguay. eamarin@yahoo.com
authors.forename: Elio Arnaldo
authors.initials: EA
authors.lastname: Marin-Sanabria
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nagashima
authors.forename: Eiji
authors.initials: E
authors.lastname: Kohmura
mesh_terms: D000367:Age Factors; D016080:Arachnoid Cysts / Q000150:complications / Q000453:epidemiology / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003388:Cranial Fossa, Posterior / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D010536:Peritoneovenous Shunt; D011183:Postoperative Complications / Q000453:epidemiology; D011597:Psychomotor Performance; D012189:Retrospective Studies; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome