Surgical micro-neuroanatomy of the formations in the posterior cranial fossa as applied to retrosigmoid and transcondyloid approaches

Modern concepts on the surgery of the tumors of the cranial basis and those of posterior cranial fossa, in particular, reside on the expertise in microarchitecture of the region. The method of injection in brain vascular system using a marked block preparation enabled to preserve anatomically correct correlations of nerves and blood vessels, as well as of other brainstem structures, and to study the microtopography of this region using the microscope and microinstruments. The study was performed using 10 block preparations of posterior cranial fossa. The microneuroanatomy of middle and lower petroclival zones was studied in detail, and the rationality of the usage of suboccipital retrosigmoidal and lateral transcondillary approaches to the pathological structures within this zone is substantiated.