Análise da correlação entre a morfologia das estruturas da fossa posterior e o desfecho clínico no tratamento neuroendoscópico do quarto ventrículo isolado

Abstract

Introduction: Isolated Fourth Ventricle (IFV) is an uncommon disease that results from the obstruction of all access routes for cerebrospinal fluid (CSF) to the fourth ventricle (FV), which expands and compresses the cerebellum and brainstem, especially in children. Endoscopic aqueductoplasty (EA) is a minimally invasive technique that aims to re-establish the CSF flow through the cerebral aqueduct, reducing the compressive effect of FV on adjacent neural structures. The correlation between EA effects on the morphology of posterior fossa content and the clinical outcomes were not well elucidated by previous studies. Objective: To evaluate the correlation between changes in the morphology of the ventricular and neural contents of the posterior fossa and the long-term clinical outcome in children with IFV after EA. Methods: A retrospective study was carried out using data from the medical records of patients who underwent EA between 2006 and 2017. Age, gender and aetiology of IFV were considered. The morphology of the posterior fossa contents was evaluated through the development of a qualitative radiological score based on FV expansion pattern and the compression of adjacent neural structures.This technique was compared with the measurement of the anteroposterior diameter of FV and intra and interobserver reproducibility was evaluated. The score values obtained by the consensus of three specialists were used to compare the preoperative data and those obtained one year after EA using a randomized distribution of tests. The radiological score was compared with the clinical outcome, represented by a change in clinical manifestations and by the Brazilian version of the paediatric functional scale.Results: Twenty children at the mean age of 4.7 years were evaluated. A haemorrhage secondary to prematurity associated with a central nervous system infection was observed in nine children. The radiological score showed a correlation with the FV measurement, with good intra-observer reproducibility and weak concordance between them. There were improvements of clinical manifestations in 90% of the cases and gains in mental state, feeding and motor function during postoperative period according to the pediatric function scale (p<0,05). Radiological score showed reduction in the FV expansion and the degree of brainstem and cerebellum deformity in the postoperative period. Conclusion: EA reduced brainstem deformities and FV expansion in most of the children with IFV and there was agreement between morphological improvement and clinical outcome. Radiological score proved useful in the evaluation and follow-up of patients.