Anatomical study of the neurovascular complex in the cerebellopontine angle region

Objective To investigate the anatomical structures of the neurovascular complex in the cerebellopontine angle region to offer anatomical materials for clinical microvascular decompression.Methods A total of 20 adult cadaveric heads fixed in 10% formalin were used for this study.After cutting cerebrum from the midbrain and the dura covering the cerebellum,the trans-suboccipital retrosigmoid approach to the CPA region was simulated.Dissections were observed and photographed gradually.Results The upper neurovascular complex included trochlear nerve,trigeminal nerve and superior cerebellar artery(SCA),superior petrosal vein,superior petrosal sinus,and anteroinferior cerebellar artery(AICA),et al.The trunk loop and its originating point of the branch of SCA usually compressed the upper trigeminal nerve entering/exiting zone of brainstem.The middle neurovascular complex mainly included abducens,facial,vestibulocochlear nerve,anteroinferior cerebellar artery(AICA),and posteroinferior cerebellar artery(PICA),et al.AICA often folded and entered the internal acoustic meatus with a labyrinthine branch.The lower neurovascular complex included glossopharyngeal,vagus,accessory and hypoglossal nerve,PICA,vertebral artery(VA),et al.Conclusion More than one compressive vessels and compressive points can be identified.A detailed anatomical study could improve the effect of microvascular compression operation.