Occipital transtentorial approach to pineal region tumors

Abstract

The surgical techniques and results of the occipital transtentorial approach to pineal region tumors using the lateral-semiprone position are described. The lateral-semiprone position and infrasplenial approach can compensate for the disadvantages of the occipital transtentorial approach and provides wide exposure of pineal region tumors. The infrasplenial approach is helpful in separating the internal cerebral veins from the tumor, especially when the tumor is tightly adherent to the veins. Pineal region tumors must be removed through a limited space between important deep veins. Therefore, piecemeal resection is mandatory to avoid injury to the veins. We have operated on 82 pineal region tumors through the occipital transtentorial approach. The extent of tumor removal primarily depended on the nature of the tumor but little on its location. There were no surgical deaths in our series, but homonymous hemianopsia occurred in 5 patients and ocular movement was disturbed in 5 patients. Ataxia of both extremities and the trunk and slight motor weakness of the right extremity occurred in one patient. Extensive removal was considered an important factor in prolonging survival in patients with teratomas, nongerminomatous malignant germ cell tumors, and pineocytomas.