title: Endoscopic considerations treating hydrocephalus caused by basal ganglia and large thalamic tumors.
abstract: BACKGROUND
  Deep basal-ganglia and large thalamic (BGT) tumors may cause secondary hydrocephalus by compressing the lateral and third ventricles. The ventricular distortion, as well as the infiltrative nature and friability of these tumors, raise specific considerations and risks when treating these patients. Treatment goals may therefore focus on cerebrospinal fluid (CSF) diversion and tissue sampling, followed by nonsurgical treatment options. We present our experience in applying endoscopic techniques for the initial management of such patients.
  
  
  METHODS
  Over a period of 15 months (January 2013 to April 2014), six patients with BGT tumors presented with signs and symptoms of increased intracranial pressure secondary to hydrocephalus. Data was collected retrospectively, including clinical, surgical, and outcome variables.
  
  
  RESULTS
  Six patients aged 9-41 years (25.6 ± 12.5) were included. Endoscopic procedures included endoscopic third ventriculostomy (4), septum pellucidotomy (5), foramen of Monro stenting (2), and endoscopic biopsy (3). One patient underwent a ventriculoperitoneal shunt placement and another stereotactic biopsy. Indications for endoscopic treatment included the infiltrative nature of the tumor preventing a resective procedure, combined with clinical deterioration related to increased intracranial pressure secondary to hydrocephalus. Pathology results included anaplastic astrocytoma (3) and anaplastic oligodendroglioma (1). Pathological sampling was not possible in two patients. Five patients enjoyed a good clinical recovery with no associated morbidity. There was one perioperative death, secondary to preoperative herniation.
  
  
  CONCLUSIONS
  Endoscopic surgery may potentially play a significant role in the initial management of patients with large basal ganglia and large thalamic tumors causing obstructive hydrocephalus. Technical nuances and individualized goals are crucial for optimal outcomes.
authors.affiliation: Department of Neurosurgery, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Roth
authors.affiliation: Department of Neurosurgery, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Zvi
authors.initials: Z
authors.lastname: Ram
authors.affiliation: Department of Neurosurgery, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Constantini
keywords: Basal ganglia; endoscopy; hydrocephalus; thalamus; tumor