O papel da membrana de Liliequist na terceiro ventriculostomia endoscópica

Abstract

Endoscopic Third Endoscopic (ETV) is a neurosurgical procedure to treat hydrocephalus. To be fully performed it is necessary opening an arachnoid structure, the Liliequist Membrane (LM). However the LM surgical anatomy from the neuroendoscopic point of view is not yet completely studied, since approach angles are different from classics descriptive and microsurgical anatomies. There is a literature discrepancy regarding the ETV efficacy, especially in children over 2 years old, which may be due to LM incomplete opening. In order to understand the LM anatomical behavior, the relationship with tuber cinereo (TC), the floor of the III Ventricle and other peculiarities, a systematic prospective observation of these characteristics was performed during the 57 surgeries. Data were recorded after the procedure and studied. Objectives were to systematize LM anatomical characteristics from neuroendoscopic perspective, understand if anatomical changes follows a pattern interfering on the procedure, and if there is correlation with patients evolution. The data analysis shows that LM characteristics are variable, making difficult the neurosurgeon management. Whenever TC anatomy modifies, or when TC and ML are separated, difficulty to perform ETV increases. When hydrocephalies are due to congenital malformations, inflammatory processes and post bleeding (prevalent in childhood), LM management is much harder, witch may explain the higher failure rate in children under 2 years of age observed in literature.