Neuroendoscopic surgery for specific forms of hydrocephalus

Abstract

Neuroendoscopic surgery was used to treat patients with various forms of hydrocephalus with specific pathophysiology, including long-standing overt ventriculomegaly in adulthood (LOVA), isolated unilateral hydrocephalus (IUH), isolated IV ventricle (IFV), disproportionately large IV ventricle (DLFV), isolated rhombencephalic ventricle (IRV), isolated quarto-ventriculomegaly (IQV), dorsal sac in holoprosencephaly (DS), and loculated ventricle (LV). A total of 26 operative procedures were performed, with neuroendoscopic surgery in 22 patients, 12 with unique forms of noncommunicating hydrocephalus and 10 with various types of postshunt isolated compartment. These procedures included III ventriculostomy, aqueductal plasty by both rostral and caudal approaches, foraminal plasty in the foramen of Monro/foramen of Magendie, septostomy, IV ventriculostomy, fenestration of septation in the loculated ventricle, fenestration of arachnoid cyst or cystic tumor obstructing a ventricle with or without tumor removal, and dorsal sac ventriculostomy. The characteristics of the cerebrospinal fluid (CSF) dynamics in the individual specific pathophysiologies were delineated by cardiac-gated cine-mode magnetic resonance imaging (MRI) before and after the endoscopic procedure. The consequent success rate (success = restoration of communication of the CSF pathway in the individual patients) was 19/22 (86.4%). The progression of ventricular dilatation was stopped in 17 of 19 patients (89.5%) in whom the endoscopic procedure was successful (radiologically arrested hydrocephalus). Improvement in the clinical symptoms and signs (clinically arrested hydrocephalus) was obtained in 15 of the patients (68.2% of all patients: 5 with LOVA, 3 with IQV, 5 with IUH and 2 with LV). Seven patients (2 LOVA, 2 IFV, 1 DS, 1 DFLV and 1 IRV) underwent a shunt procedure after the neuroendoscopic procedure(s). The postoperative changes of ventriculomegaly were complicated, reflecting the differences in the brain parenchymal compliance and postoperatively corrected CSF flow dynamics in the major CSF pathway.

Subdural Hygroma as a Complication of Endoscopic Neurosurgery. Two Case Reports.

“…Many authors state that CSF flows from the third ventricle into the basal cisterns via the subarachnoid space of the interpeduncular cistern. 8,15,20,33,34) CSF volume following ETV is dependent upon the``normal'' pathways of absorption, so producing a slower decompression of the ventricular system and minimizing the risk of subdural collection of any kind. Furthermore, to prevent a collapse of the ventricular system, which would be the simplest explanation for the formation of the subdural hygroma, only a minimal amount of CSF is lost during the intervention.…”

“…Endoscopic third ventriculostomy (ETV) has proved to be both safe and effective in the treatment of obstructive hydrocephalus, and more than 80% of cases can be managed without extracranial shunting. 1,10,15,20,24,28,33,39,45,47) Other endoscopic techniques include aqueduct intubation or aqueductoplasty. 35,42) Neuroendoscopy is also indicated for the treatment of ventricular and paraventricular arachnoid cysts by fenestration or marsupialization of the cysts into the ventricles or basal subarachnoid space.…”

Ventricular endoscopy in the pediatric population: review of indications

“…In these cases, endoscopic septostomies may be performed to form a communication between the lateral ventricles, which have been demonstrated to eliminate the need for CSF shunting or ventricular catheters altogether [68][69][70]. However, results for such procedures have been mixed.…”

Hydrocephalus Research Update -Controversies in Definition and Classification of Hydrocephalus-

“…16) V. Proposal for comprehensive``Multi-categorical Hydrocephalus Classification'' (McHC) Various items for classification of hydrocephalus were previously proposed, such as associated anomalies/underlying lesions, CSF circulation/intracranial pressure (ICP) patterns, clinical features, and other categories. No definitive classification has been published comprehensively to cover the variety of these aspects.…”

“…Neuroendoscopic surgery was used to treat patients with various forms of isolated compartments with specific pathophysiology 16) including IUH, IFV, disproportionately large fourth ventricle (DLFV), isolated rhombencephalic ventricle (IRV), isolated central canal dilatation (ICCD), isolated quarto-ventriculomegaly (IQV), dorsal sac in holoprosencephaly (DS), and loculated ventricle (LV). 16) V. Proposal for comprehensive``Multi-categorical Hydrocephalus Classification'' (McHC) Various items for classification of hydrocephalus were previously proposed, such as associated anomalies/underlying lesions, CSF circulation/intracranial pressure (ICP) patterns, clinical features, and other categories.…”