Does the superior petrosal exist in all human brains?: A unique anatomic specimen and venous considerations for posterior fossa surgery Ken Matsushima MD; Eduardo Ribas; Hiro Kiyosue; Noritaka Komune; Koichi Miki; Albert L. Rhoton MD Department of Neurological surgery, University of Florida, Gainesville, FL Department of Radiology, Oita University Faculty of Medicine, Oita, Japan,

Introduction Conclusions Cadaveric cerebellopontine angle with Venographic images and illustration Occlusion of the superior petrosal vein, In these unique cases, in which the absence of the left superior petrosal one of the most constant and largest superior petrosal and are venous structures in the posterior fossa, absent, care should be directed to veins and sinus. may result in venous complications. The preserving the collateral drainage through purpose of this study is to call attention to the galenic and tentorial tributaries. a unique variant in which the superior Although surgical strategies for petrosal veins and sinus were absent intraoperative management and unilaterally, and venous drainage was preservation of venous structures are still through the galenic and tentorial groups. controversial, knowledge of the possible anatomical variations is considered Methods essential to improving surgical outcomes. Anatomical dissection of one formalin-fixed adult head, in which the left superior References petrosal vein and sinus were not present. Elhammady MS, Heros RC. : To Supplementary, a detailed analysis of Sacrifice or Not to Sacrifice, That Is the venographic images of a patient without Question. World neurosurgery. Jun 18 2013. any identifiable superior petrosal vein or sinus. Ueyama T, Al-Mefty O, Tamaki N. Bridging veins on the tentorial surface of the cerebellum: a microsurgical anatomic study and operative Results considerations. Neurosurgery. Nov On the right side, the superior petrosal The superior petrosal veins, described as 1 1998;43(5):1137-1145. sinus and a single petrosal vein were to 3 bridging veins, emptying into the In the left cerebellopontine angle, the clearly identified (white arrowhead). superior petrosal sinus, are the major Tubbs RS, Mortazavi MM, Krishnamurthy S, superior petrosal vein and sinus were not However, on the left side, the superior drainage pathway of the petrosal group of Verma K, Griessenauer CJ, Cohen-Gadol AA. identified, and their normal tributaries petrosal sinus could not be identified. The posterior fossa veins. In the cases The relationship between the superior petrosal drained into the veins of the galenic and left vein of the cerebellopontine fissure presented, the superior petrosal vein and sinus and the porus trigeminus: an anatomical tentorial groups and the contralateral drained directly into the tributaries of the sinus were absent and venous drainage study. Journal of neurosurgery. Nov transverse pontine vein (A). The well- vein of Galen through the well-developed was through the galenic and tentorial 2013;119(5):1221-1225. developed galenic and tentorial groups, lateral mesencephalic vein, and the left groups, including the lateral including the lateral mesencephalic vein inferior hemispheric vein formed a bridging mesencephalic or on the Koerbel A, Gharabaghi A, Safavi-Abbasi S, et al. and a bridging vein on the tentorial vein that drained through a short tentorial tentorial cerebellar surface. Venous complications following petrosal vein surface, compensate for the absence of sinus into the transverse sinus (Fig. 2). The sectioning in surgery of petrous apex the petrosal group (B and C). After illustration shows that the area normally meningiomas. European journal of surgical drained by the superior petrosal veins oncology : the journal of the European Society removing the cerebellum, the absence of drained instead into the vein of Galen, of Surgical Oncology and the British Association the superior petrosal sinus and vein is of Surgical Oncology. Jul 2009;35(7):773-779. visible in the left posterior fossa (red tentorial sinus, and contralateral transverse pontine vein (red arrows, Fig. 3). arrowheads, D). In the right posterior fossa, a single superior petrosal vein Learning Objectives emptied into a superior petrosal sinus By the conclusion of this session, along the petrous ridge (E). participants should be able to: 1) Describe the anatomy of posterior fossa veins, and 2) Discuss the venous complications of posterior fossa surgeries.