A, Posterolateral view. The posterior temporal lobe has been elevated to expose the vein of Labbé and the posterior temporal and occipital veins from the lateral surface joining the transverse sinus and the temporobasal veins from the basal surface of the temporal lobe emptying into the tentorial sinuses. Some veins from the lateral surface of the temporal and occipital convexity do not pass directly to the transverse sinus, but turn medially under the basal surface to empty into sinuses in the tentorium. B, Enlarged view. The vein of Labbé is exposed anteriorly. Reaching the tentorial incisura by the posterior subtemporal route may require the sacrifice of multiple temporobasal and occipitobasal veins draining into the tentorial sinuses in addition to the vein of Labbé and other veins from the lateral surface of the temporal and occipital lobes. C, Superior view of the tentorium. On the left side, the temporobasal and occipitobasal veins converge on two short tentorial sinuses located just medial to the transverse sinus. On the right side, the vein of Labbé and a posterior temporal vein drain directly into the transverse sinus. Another sinus within the left tentorium (yellow arrow) receives drainage from the cerebellum and passes medially across the tentorium to empty into the torcular herophi. D, The left half of the tentorium has been removed. The bridging cerebellar vein, shown in D with a yellow arrow, empties into the tentorial sinus shown in C with the yellow arrow. E, Lateral surface of the right temporal lobe and sylvian fissure in another specimen. The anterior part of the superficial sylvian vein is small and the posterior part that empties into the vein of Labbé is larger. A middle temporal vein that courses along the superior temporal sulcus forms a bridging vein that passes around the lower margin of the hemisphere to empty into a tentorial sinus. The sylvian vein also has connections with the superior sagittal sinus through two anastomotic veins of Trolar D, one crosses the frontal lobe and the other crosses the parietal lobe. The temporosylvian veins drain the superior temporal gyrus and empty into the superficial sylvian and middle temporal veins. (Images courtesy of AL Rhoton, Jr.)