A, Right lateral view. The veins draining this cerebral hemisphere are directed to the superior sagittal and transverse sinuses. The superficial sylvian vein is small. One small anastomotic vein of Trolard links the superior sagittal sinus and sylvian fissure. B, Another right hemisphere. The superficial sylvian vein is large. There is minimal anastomosis between the superficial sylvian vein and the veins draining into the superior sagittal sinus, but there is a connection between the superficial sylvian vein and the vein of Labbé. In opening the sylvian fissure by the pterional approach, the drainage pattern for the whole hemisphere is not seen. Sacrificing the superficial sylvian vein shown in A would probably not affect the hemisphere, but sacrificing the large superficial sylvian vein shown in B could lead to venous drainage problems along the frontal and temporal lobes adjoining the sylvian fissure. C, Left hemisphere. A superficial sylvian vein has a large connection with the vein of Labbé. In addition, two small or duplicate veins of Trolard connect the superior sagittal sinus and the sylvian vein. The posterior one joins the superficial sylvian vein near the junction with the vein of Labbé. D, Left hemisphere. There are no significant connections between the veins in the sylvian fissure and the superior sagittal sinus, but there is a large anastomosis between the superficial sylvian vein and the vein of Labbé. E, Right hemisphere. Dupli-cate veins of Trolard connect the superior sagittal sinus to the superficial sylvian veins; one crosses the frontal lobe and one crosses the parietal lobe. The superficial sylvian vein also has a large anastomosis with the vein of Labbé. F, Right hemisphere. A single large vein of Trolard coursing in the region of the central sulcus connects the superficial sylvian vein and the superior sagittal sinus. This is no well-developed vein of Labbé, but a large vein from the posterior parietal and temporal areas (yellow arrow) empties into the superior sagittal sinus. (Images courtesy of AL Rhoton, Jr.)