Endoscopic treatment of midline cerebral cysts.

Axial cerebral cysts of various location and origin are relatively rare lesions. Endoscopic neurosurgery has made them amenable for safe intervention even in vital brain regions. Neuroendoscopic treatment was used by the author in 35 patients during the last 7 years without permanent morbidity or mortality. The aim of the surgery was to fenestrate the cyst or to perform cyst exstirpation to relieve the pressure effect on the surrounding functioning neural tissue and to reestablish the patency of cerebrospinal fluid pathways, as well as histological verification of the cyst origin. Contemporary imaging modalities are capable of diagnostic evaluation, but the detailed anatomical relationship to the surrounding structures can be visually analysed completely together with understanding of their functional effects only during endoscopic surgeries, supported by the results of imaging. Therefore the precision of endoscopic surgeries was substantially enhanced and during the surgery a large amount of knowledge enriching the contemporary information about the cerebrospinal fluid flow through the cerebral ventricular system and blood circulation in the deep cerebral venous system and the relationship of these veins to hydrocephalus was obtained (Tab. 1, Fig. 9, Ref. 11).