Endoscopic third ventriculostomy through lamina terminalis: A feasible alternative to standard endoscopic third ventriculostomy.

Abstract

Endoscopic third ventriculostomy (ETV), wherein a stoma is created in the floor of the third ventricle, has now become the standard procedure for noncommunicating hydrocephalus across the world. However, in certain situations, this procedure may pose technical difficulties. These include a narrow prepontine space, vascularized third ventricular floor, the presence of prominent blood vessels traversing within the prepontine space, significant basal exudates, thickened and ill-defined third ventricular floor, and distorted floor anatomy. In such situations, an endoscopic lamina terminalis opening may provide a safer and more effective alternative to the standard technique. The paper aims to discuss the different indications, technical nuances, and outcome of endoscopic third ventriculostomy through the lamina terminalis (ETV LT) utilizing the standard transventricular transforaminal route. A total of 240 patients underwent ETV between January 2007 and January 2014. Of these patients, 8 patients required an EVT LT and these patients formed the subset of patients for the present study. In all the 8 patients, the decision to perform fenestration of the LT during the endoscopic procedure was taken intraoperatively. We qualified a procedure to be a success when a second procedure was not required subsequently. Of the eight patients in whom ETV LT was done, four had aqueductal stenosis (including one case of post-primary ETV), three patients were diagnosed with post-meningitic hydrocephalus, and the remaining patient had a posterior fossa tumor. The procedure was successful in 6 of our patients who did not require a second procedure till the last follow-up. Endoscopic transventricular transforaminal LT fenestration with a flexible neuroendoscope is a feasible alternative to the standard ETV when technical difficulties precludes safe performance of the latter procedure.