Avaliação da abordagem neuroendoscópica no tratamento da hidrocefalia monoventricular

Abstract

Isolated expasion of one lateral ventricle, when unrelated to the ex-vacuum phenomenon due to hemispheric atrophy, is caused by unilateral obstruction of the foramen of Monro (FM). Increased pressure, caused by unilateral accumulation of the cerebrospinal fluid, causes deviation of the cerebral structures and progressively increases intracranial pressure. This condition is referred, in medical literature, as monoventricular hydrocephalus (MH) or unilateral hydrocephalus and surgical treatment is imperative. For the last 20 years, endoscopy has been the treatment of choice for this condition. Terminology application of this type of hydrocephalus is not uniform in the literature and the best endoscopic technique still remains undefined, mainly by limited number of published cases. To discuss the terminology used in the literature for hydrocephalus restricted to one lateral ventricle, to determine the endoscopic techniques used to treat the cases studied comparing the results with those presented in the literature and to present an endoscopic treatment flowchart of MH based on data obtained with this case series.Material and Method: in order to evaluate the best term for unilateral hydrocephalus due to FM obstruction, 19 English-language terms were searched in the PubMed database (http://www.ncbi.nlm.nih.gov/ pubmed). For this case series, a retrospective study of patients with hydrocephalus operated on by neuroendoscopy at the Pedro Ernesto University Hospital from 1995 to 2014 was carried out. Patients with a diagnosis of MH were selected. MH cases secondary to tumors were excluded. Results: 194 articles were obtained. All terms that did not describe lateral ventricle hydrocephalus or that described the cardiac ventricle were excluded. Of the 19 terms, only 7 continued for discussion. In the case review, 8 patients with different causes of MH were found: FM atresia, neurocysticercosis, arachnoid cyst, membrane obstruction of theFM and FM stenosis. The procedures performed were septostomy, foraminoplasty, membrane and cyst opening, lesions removal, choroid plexus coagulation and choroidal fissure opening. In all cases the endoscope was inserted into the hydrocephalic ventricle by precoronal frontal craniostomy. All patients had their MH completely solved by the endoscopic procedures. This terminological review suggests that hydrocephalus confined to one lateral ventricle without other sites of obstruction is best described by the terms unilateral hydrocephalus or HM, the first being the most popular. However, the use of terms inappropriately is not uncommon in the literature and may distort results interpretation. The endoscopic techniques used in our cases, with the exception of choroidal fissure opening, were described in the literature, also with a high success rate. The entry through the dilated lateral ventricle is not a consensus in the literature but it allows to perform all the endoscopic procedures necessary to restore cerebrospinal fluid flow and allows direct inspection of FM for etiological clarification. The endoscopic techniques employed varied according to the etiology of MH and can be used together without increasing morbidity. These techniques were arranged in anflowchart created based on this case series.