title: Microsurgical anatomy and internal architecture of the brainstem in 3D images: surgical considerations.
abstract: OBJECT Brainstem surgery remains a challenge for the neurosurgeon despite recent improvements in neuroimaging, microsurgical techniques, and electrophysiological monitoring. A detailed knowledge of the microsurgical anatomy of the brainstem surface and its internal architecture is mandatory to plan appropriate approaches to the brainstem, to choose the safest point of entry, and to avoid potential surgical complications. METHODS An extensive review of the literature was performed regarding the brainstem surgical approaches, and their correlations with the pertinent anatomy were studied and illustrated through dissection of human brainstems properly fixed with 10% formalin. The specimens were dissected using the fiber dissection technique, under ×6 to ×40 magnification. 3D stereoscopic photographs were obtained (anaglyphic 3D) for better illustration of this study. RESULTS The main surgical landmarks and their relationship with the cerebellum and vascular structures were identified on the surface of the brainstem. The arrangements of the white matter (ascending and descending pathways as well as the cerebellar peduncles) were demonstrated on each part of the brainstem (midbrain, pons, and medulla oblongata), with emphasis on their relationships with the surface. The gray matter, constituted mainly by nuclei of the cranial nerves, was also studied and illustrated. CONCLUSIONS The objective of this article is to review the microsurgical anatomy and the surgical approaches pertinent to the brainstem, providing a framework of its external and internal architecture to guide the neurosurgeon during its related surgical procedures.
authors.affiliation: Institute of Neurological Sciences (ICNE), São Paulo;|Microneurosurgery Laboratory, Beneficência Portuguesa Hospital, São Paulo;|Department of Neurological Surgery, Hospital UNIVALLE, Cochabamba-Cercado, Bolivia; and.
authors.forename: Richard Gonzalo
authors.initials: RG
authors.lastname: Párraga
authors.affiliation: Institute of Neurological Sciences (ICNE), São Paulo;|Microneurosurgery Laboratory, Beneficência Portuguesa Hospital, São Paulo;
authors.forename: Lucas Loss
authors.initials: LL
authors.lastname: Possatti
authors.affiliation: Institute of Neurological Sciences (ICNE), São Paulo;|Microneurosurgery Laboratory, Beneficência Portuguesa Hospital, São Paulo;
authors.forename: Raphael Vicente
authors.initials: RV
authors.lastname: Alves
authors.affiliation: Department of Surgery-LIM 02, University of São Paulo Medical School (FMUSP), São Paulo;
authors.forename: Guilherme Carvalhal
authors.initials: GC
authors.lastname: Ribas
authors.affiliation: Department of Neurosurgery, Yeditepe University School of Medicine, Istanbul, Turkey.
authors.forename: Uğur
authors.initials: U
authors.lastname: Türe
authors.affiliation: Institute of Neurological Sciences (ICNE), São Paulo;|Microneurosurgery Laboratory, Beneficência Portuguesa Hospital, São Paulo;|Department of Neurosurgery, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil;
authors.forename: Evandro
authors.initials: E
authors.lastname: de Oliveira
mesh_terms: D001933:Brain Stem / Q000000981:diagnostic imaging* / Q000601:surgery*; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000601:surgery; D003391:Cranial Nerves / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008526:Medulla Oblongata / Q000000981:diagnostic imaging / Q000601:surgery; D008636:Mesencephalon / Q000000981:diagnostic imaging / Q000601:surgery; D008866:Microsurgery / Q000379:methods*; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000601:surgery; D010780:Photogrammetry / Q000379:methods; D011149:Pons / Q000000981:diagnostic imaging / Q000601:surgery; D012016:Reference Values
keywords: CN = cranial nerve; brainstem; fiber dissection; microsurgical anatomy; posterior fossa; safe entry zone; surgical approaches