title: Vertical extraventricular functional hemispherotomy: a new variant for hemispheric disconnection. Technical notes and results in three patients.
abstract: OBJECTIVE
  Hemispherectomy and disconnective hemispherotomy are the most effective epilepsy surgical procedures for the treatment of epilepsy due to hemispheric pathologies such as Sturge-Weber syndrome, diffuse hemispheric cortical dysplasia, and posttraumatic and postischemic focal lesions. Disconnective hemispherotomy is nowadays preferred to reduce surgical morbidity in term of early and late complications (i.e., cerebral superficial hemosiderosis). Despite the number of existing technical variants conceived to further reduce the amount of brain tissue to be removed, postoperative hydrocephalus still persists and may account for an average incidence of 15-41% according to different series and reviews. A new variant of disconnective vertical hemispherotomy we termed vertical extraventricular parasagittal hemispherotomy is described aiming to further reduce the amount of removed brain tissue and so the risk of postoperative hydrocephalus in favor of a pure hemispheric disconnection.
  
  
  METHODS
  Three patients affected by drug-resistant epilepsy due to different hemispheric pathologies (posttraumatic epilepsy, Sturge-Weber syndrome, diffuse hemispheric cortical dysplasia) were considered to be candidates for vertical extraventricular parasagittal hemispherotomy disconnective based on presurgical evaluation protocol. The oldest patient was 15 years old, the two youngest were both 2 years old.
  
  
  RESULTS
  None of the patients experienced early and late surgical complications. After a mean follow-up of 36 months (range 12-60 months), two patients were seizure free, one relapsed seizures 18 months later. Postoperative hydrocephalus never occurred.
  
  
  CONCLUSIONS
  Vertical extraventricular parasagittal hemispherotomy may be an efficacious and less invasive technique as it consists in a pure disconnection of the hemisphere with less amount of brain tissue removed and a theoretical reduced risk of postoperative hydrocephalus.
authors.affiliation: Neurosurgery - Department of Neurosciences, Anna Meyer Pediatric Hospital, Viale Pieraccini 24, 50139, Florence, Italy. flavio.giordano@meyer.it.
authors.forename: Flavio
authors.initials: F
authors.lastname: Giordano
authors.affiliation: Neurosurgery - Department of Neurosciences, Anna Meyer Pediatric Hospital, Viale Pieraccini 24, 50139, Florence, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Spacca
authors.affiliation: Pediatric Neurology Clinic - Department of Neurosciences, Anna Meyer Pediatric Hospital, Florence, Italy.
authors.forename: Carmen
authors.initials: C
authors.lastname: Barba
authors.affiliation: Pediatric Neurology Clinic - Department of Neurosciences, Anna Meyer Pediatric Hospital, Florence, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mari
authors.affiliation: Pediatric Neurology Clinic - Department of Neurosciences, Anna Meyer Pediatric Hospital, Florence, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Pisano
authors.affiliation: Pediatric Neurology Clinic - Department of Neurosciences, Anna Meyer Pediatric Hospital, Florence, Italy.
authors.forename: Renzo
authors.initials: R
authors.lastname: Guerrini
authors.affiliation: Neurosurgery - Department of Neurosciences, Anna Meyer Pediatric Hospital, Viale Pieraccini 24, 50139, Florence, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Genitori
mesh_terms: D000293:Adolescent; D000927:Anticonvulsants / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000150:complications; D002675:Child, Preschool; D000069279:Drug Resistant Epilepsy / Q000188:drug therapy / Q000209:etiology / Q000601:surgery*; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D006391:Hemangioma / Q000150:complications; D038421:Hemispherectomy / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications; D013341:Sturge-Weber Syndrome / Q000150:complications; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants
keywords: Epilepsy surgery; Hemispherectomy; Hemispherotomy disconnective technique; Hydrocephalus; Pediatric epilepsy