Morphometric study of the human brainstem and its neurovascular relations.

AIM: To provide a concise description of the external configuration, its internal correspondence and the neurovascular relations of the brainstem with morphometric data that can be useful in surgical planning. MATERIAL and METHODS: The study was conducted on formalin fixed brainstem specimens, which were harvested with respect to the topographic anatomy. Macroscopic measurements were performed with a Vernier caliper. RESULTS: The anatomical structures on the ventral and dorsal aspects of the brainstem are described and illustrated schematically. Their dimensions are also graphically represented using the mean values. Serial axial sections through the brainstem demonstrate the internal correspondence of its external features. Then, the apparent origins and the proximal diameters of the cranial nerves and the arteries of the posterior circulation as well as their anatomical relations are presented. CONCLUSION: The external morphometry of the brainstem correlated with the position of the internal structures provides landmarks with applicability in neurosurgery especially in the fields of intrinsic brainstem lesions, posterior fossa and fourth ventricle surgery.