title: The disconnected shunt: a window of opportunities.
abstract: BACKGROUND
  Shunt disconnection (SD), or migration of the distal end to extra-peritoneal tissues, may lead to shunt malfunction or be diagnosed incidentally. We present a systematic approach for treatment options that is tailored to each patient's personalized history, CSF physiology, and distribution (MRI), as well as a careful informed consent process.
  
  
  METHODS
  We present two algorithms, for symptomatic and asymptomatic SD. In cases presenting with symptomatic elevated intracranial pressure, a distal shunt revision (DSR), or, in selected patients, an endoscopic third ventriculostomy (ETV), should be performed. In asymptomatic patients, several options exist. The first decision is whether to intervene or follow. When action is recommended, a planned shunt revision is possible. The other option is to externalize the shunt and close it under careful clinical and radiological follow-up. Patients are then stratified to three main groups-those that are not shunt dependent, those that have radiological evidence of obstructed hydrocephalus, and the remaining patients. Patients are accordingly treated by ligation of the shunt without or with an endoscopic third ventriculostomy or with a distal shunt revision.
  
  
  RESULTS
  Twenty-one patients were diagnosed with a shunt disconnection. Seventeen were diagnosed at screening tests, while four were presented with shunt malfunction symptoms. Sixteen incidental cases were followed (3-111 months, 39 ± 37), of which three became symptomatic. One patient had an elective ETV followed by a DSR, and three followed-up patients became symptomatic and thus underwent surgery. All symptomatic patients underwent treatment (5 DSR, 2 ETV).
  
  
  CONCLUSIONS
  Shunt disconnection opens a window of opportunities into better understanding the pathophysiology of the hydrocephalic process in a specific patient. Distal shunt revision or ETV (in selected patients) is indicated in symptomatic cases. In asymptomatic patients, options exist. Choosing between those options mandates a careful individual assessment and a detailed informed consent process.
authors.affiliation: Department of Pediatric Neurosurgery, Dana Children's Hospital, Tel Aviv Medical Center, Tel Aviv University, 6 Weizman Street, 64239, Tel Aviv, Israel. jonaroth@gmail.com.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Roth
authors.affiliation: Department of Pediatric Neurosurgery, Dana Children's Hospital, Tel Aviv Medical Center, Tel Aviv University, 6 Weizman Street, 64239, Tel Aviv, Israel.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Constantini
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects*; D002648:Child; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000503:physiopathology* / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000628:therapy*; D012189:Retrospective Studies
keywords: Endoscopic third ventriculostomy; Shunt externalization; Shunt ligation; Shunt revision