Endoscopic third ventriculostomy in patients with myelomeningocele after shunt failure.

PURPOSE: Myelomeningocele (MMC) is the most frequent form of spina bifida. Moreover, 90% of patients with MMC have hydrocephalus and require shunt placement. However, shunt failure management in such patients typically involves several shunt revisions, increasing the risk for morbidity and mortality. In this study, we report our experience with endoscopic third ventriculostomy (ETV) in MMC patients with shunts in a Brazilian institution.

METHODS: Patients with MMC who presented with shunt failure and underwent ETV alone between January 1996 and December 2016 were included in this study. Patients who had undergone endoscopic choroid plexus cauterization (CPC) or had non-shunted MMC hydrocephalus were excluded. Various data related to the ETV procedure were collected for each patient, including features, operative characteristics, complications, and ETV success. The follow-up period for the patients was 6-12 months. ETV success scores (ETVSSs) were calculated retrospectively for each patient to compare the predicted success of the procedure with the actual success at 6 months after ETV.

RESULTS: Forty-three MMC patients with shunt failure were included in this study. Of them, 16 (37.2%) had a previous central nervous system (CNS) infection and 4 (9.3%) had complications. Two neuroendoscopies were interrupted, one because of anatomic impossibility due to thickening of the interthalamic adhesion, obliterating the floor of the third ventricle, and another because of intraoperative hemorrhage. One patient developed hyponatremia during the postoperative period, whereas another developed reversible paresis of the oculomotor nerve. The ETVSS predicted a success rate of 49.6% compared with the actual ETV success rate of 53.48% (23 patients) at 6 months. At 12 months, the actual success rate was 41.9% (18 patients). All patients survived the procedure.

CONCLUSION: Our findings indicate that ETV is an effective procedure for managing MMC-related hydrocephalus after shunt failure. The expertise of the neurosurgeon in neuroendoscopy procedures is often the deciding factor when choosing a management option. Accordingly, less experienced neurosurgeons should be warned of the risks of this procedure.