Basal interhemispheric supra- and/or infrachiasmal approaches via superomedial orbitotomy for hypothalamic lesions: preservation of hypothalamo-pituitary functions in combination treatment with radiosurgery.

Although several approaches to the hypothalamus have been used, none is able to give full views of the hypothalamus. The risk of permanent morbidity for hypothalamo-pituitary functions is still high, especially in patients with craniopharyngioma. Basal interhemispheric supra-chiasmal or infra-chiasmal approaches via superomedial orbitotomy were developed for better visualization of the hypothalamus. Operative techniques and results, including combination treatment with radiosurgery, are reported. Twelve patients with tumors compressing the hypothalamus upward or extending into the III ventricle, or both, were operated on: 3 tumors were removed totally, 6 tumors subtotally and 3 tumors partially. Six patients received radiosurgery for residual tumor. Four patients with hypopituitarism preoperatively required oral corticosteroids and thyroid hormones postoperatively. The basal interhemispheric approach via superomedial orbitotomy is useful for better visualization of the hypothalamus and preservation of hypothalamo-pituitary functions.