Right Combined Supra/Infratentorial Approach. A, Division of the transverse sinus, if it is small and well collateralized, provides an exposure that combines both the supratentorial and infratentorial approaches. B to D, Supratentorial views. B, The venous complex above the pineal body can be observed bilaterally from above. C, The vermis has been retracted, and the vein of Galen has been displaced to the left, to expose the pineal body, superior and inferior colliculi, trochlear nerves, and superior peduncles. Exposure of the lateral part of the contralateral half of the quadrigeminal cistern is better than can be achieved with the occipital transtentorial approach. D, The exposure, which is wider than that of the occipital transtentorial approach, has been directed laterally along the side of the brainstem to the ambient cistern, where the lateral margin of the cerebral peduncle and the P2p segment are exposed. (Images courtesy of AL Rhoton, Jr.)