Development of flexible ventriculoscope (Yamadori-type VII) and its application to experimental animals.

We developed a new ventriculoscope (Yamadori-type VII), a 2.1 mm calibrated fiberscope with a monopolar coagulator, that can be inserted from the cisterna cerebellomedullaris into the third cerebral ventricle of experimental animals, like dogs. With the improved performance of the neuroendoscope compared to its prototype, Yamadori III, it was possible to inspect clearly and to produce electrocoagulative lesions accurately on any part of the intraventricular structures with minimal injury to nearby vital brain areas.