Abstract
In 30 cases, an analysis of the transoral transpharyngeal approach to the ventral brain stem was made. All preparations were performed in situ using microscopic and endoscopic methods. Modern imaging techniques and computer-assisted approach planning were also applied and discussed. To show the subarachnoidal cisterns and receive a realistic impression of the tissue, the preparation was performed 26 times in non-fixed cases. To use currently available equipment safely, it is important to take anatomical details into account when determining the size and type of the clivus window to be used. Preparation of the preclival tissue is the most difficult step. It requires a precise approach plan to ensure safe closure. This selective approach gives the best access to the lower ventral brainstem, without any of the problems associated with other approaches to the same region. The transoral transpharyngeal approach is described here within the context of minimally invasive techniques, in particular endoscopy, modern imaging methods, and computer-assisted approach planning.