The Infratentorial-Supracerebellar Exposure of Tumors in the Pineal Area

Abstract

Nine pineal area lesions were operated upon by the infratentorial-supracerebellar approach. There was one operative death and one death due to disseminated germinoma recurrence 2 1/2 years postoperatively. The remaining seven patients have shown no sign of recurrence and are neurologically normal. The surgical method that has evolved through these nine cases is discussed. The infratentorial-supracebebellar exposure is an excellent one for lesions in the region of the pineal gland, posterior 3rd ventricle, and superior cerebellar vermis. Access is less hampered by the major tributaries of the vein of Galen than with the supratentorial operations. This approach is also a useful extension of the standard posterior fossa exploration when dealing with primarily subtentorial lesions that involve the dorsal midbrain or herniate upward.

Neurosurgical venous considerations for tumors of the pineal region resected using the infratentorial supracerebellar approach

“…The infratentorial supracerebellar (ITSC) approach (10)(11)(12) and the occipital transtentorial (OTT) approach (13)(14)(15) are the standard approaches for the microsurgical resection of pineal-region tumors. The ITSC approach is a midline approach and provides definite orientation of the tumor and surrounding structures (16).…”

“…On the other hand, Page reported that severe cerebellar swelling occurred after the division of all vermian bridging veins and one hemispheric bridging vein. He strongly advocated the importance of preserving the hemispheric bridging veins (12). We always divide only the thin bridging veins and try to preserve the thick ones.…”

Avoidance of postoperative acute cerebellar swelling after pineal tumor surgery

“…In the majority of my cases with pineal tumors, I have chosen the supracerebellar infratentorial approach, which constitutes the most common access route to the pineal region [7]. To avoid excessive downward retraction of the superior cerebellar vermis, I used the paraculminal route either on one side or bilaterally.…”

Pineal Region Tumors

“…Under microscope magnification, severing the bridging veins between cerebellum and tentorium is a crucial point to gain the corridor carrying out the approach through. As some authors reported (Ueyama et al, 1998;Bruce & Stein, 1993;Fain et al, 1994;Page 1977), bridging veins in the midline can be sacrificed but this could lead to cerebellar venous infarction and consequent swelling. The arachnoidal adhesions should be released on the surface of cerebellum and all along the tentorial incisura as well, where they are particularly thickened.…”