title: Midline and off-midline infratentorial supracerebellar approaches to the pineal gland.
abstract: OBJECTIVE A common approach to lesions of the pineal region is along the midline below the torcula. However, reports of how shifting the approach off midline affects the surgical exposure and relationships between the tributaries of the vein of Galen are limited. The purpose of this study is to examine the microsurgical and endoscopic anatomy of the pineal region as seen through the supracerebellar infratentorial approaches, including midline, paramedian, lateral, and far-lateral routes. METHODS The quadrigeminal cisterns of 8 formalin-fixed adult cadaveric heads were dissected and examined with the aid of a surgical microscope and straight endoscope. Twenty CT angiograms were examined to measure the depth of the pineal gland, slope of the tentorial surface of the cerebellum, and angle of approach to the pineal gland in each approach. RESULTS The midline supracerebellar route is the shortest and provides direct exposure of the pineal gland, although the culmen and inferior and superior vermian tributaries of the vein of Galen frequently block this exposure. The off-midline routes provide a surgical exposure that, although slightly deeper, may reduce the need for venous sacrifice at both the level of the veins from the superior cerebellar surface entering the tentorial sinuses and at the level of the tributaries of the vein of Galen in the quadrigeminal cistern, and require less cerebellar retraction. Shifting from midline to off-midline exposure also provides a better view of the cerebellomesencephalic fissure, collicular plate, and trochlear nerve than the midline approaches. Endoscopic assistance may aid exposure of the pineal gland while preserving the bridging veins. CONCLUSIONS Understanding the characteristics of different infratentorial routes to the pineal gland will aid in gaining a better view of the pineal gland and cerebellomesencephalic fissure and may reduce the need for venous sacrifice at the level of the tentorial sinuses draining the upper cerebellar surface and the tributaries of the vein of Galen.
authors.affiliation: Department of Neurosurgery, University of Florida College of Medicine, Gainesville, Florida.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsuo
authors.affiliation: Department of Neurosurgery, University of Florida College of Medicine, Gainesville, Florida.
authors.forename: Serhat
authors.initials: S
authors.lastname: Baydin
authors.affiliation: Department of Neurosurgery, University of Florida College of Medicine, Gainesville, Florida.
authors.forename: Abuzer
authors.initials: A
authors.lastname: Güngör
authors.affiliation: Department of Neurosurgery, Japanese Red Cross Fukuoka Hospital; and.
authors.forename: Koichi
authors.initials: K
authors.lastname: Miki
authors.affiliation: Departments of 3 Otolaryngology Head and Neck Surgery and.
authors.forename: Noritaka
authors.initials: N
authors.lastname: Komune
authors.affiliation: Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Kurogi
authors.affiliation: Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Iihara
authors.affiliation: Department of Neurosurgery, University of Florida College of Medicine, Gainesville, Florida.
authors.forename: Albert L
authors.initials: AL
authors.lastname: Rhoton
mesh_terms: D002531:Cerebellum / Q000601:surgery*; D006801:Humans; D008866:Microsurgery / Q000379:methods*; D044583:Neuroendoscopy / Q000379:methods*; D038361:Neuronavigation / Q000379:methods; D019635:Neurosurgical Procedures / Q000379:methods*; D010870:Pineal Gland / Q000601:surgery*
keywords: CTA = CT angiography; endoscopic anatomy; infratentorial supracerebellar approach; microsurgical anatomy; pineal gland; quadrigeminal cistern; tentorial sinuses; vein of Galen