[Surgical technique in operations for brainstem gliomas]

Abstract

The article presents an MRI-based classification of brainstem gliomas into focal, cervicomedullary, dorsal exophytic and diffuse ones. This classification provides the basis for specifying indications for surgical treatment and outcome. The article also presents the most frequent approaches to the midbrain, pons and medulla oblongata. These approaches include the pterional, orbito-zygomatic, subtemporal transtentorial and supracerebellar approaches to the midbrain. Suboccipital, trans fourth ventricle, subtonsillar, retrosigmoid and anterior petrosal approaches were used in the case of the pons. Suboccipital, trans fourth ventricle and transcondylar approaches were applied for the removal of tumors of medulla oblongata. This paper elaborates on rare approaches: transcondylar, paramedian-supracerebellar, subtonsillar and anterior petrosal ones effectively applied in our clinic. The resection of brain stem tumors is performed by piecemeal resection and not by removal en bloc. We stress the significance of safe entry zones to the brain stem and places at the fossa rhomboidea whose impairment may cause severe disability. Lesion of trigonum nervi hypoglossi, trigonum nervi vagi, colliculus facialis and fasciculus longitudinalis medialis leads to severe disability or death of the patient.