Comentários neurocirúrgicos e fisiológicos sobre a secção da haste pituitária em seres humanos (miscotomia)

Abstract

Four years after the first hypophysectomy in a patient suffering from breast cancer 22 > 25 we started in november 1955 the section of the pituitary stalk 18 for three reasons :(a) Surgical hypophysectomy was often proved to be incomplete when at post mortem one takes care to estimate the significance of the anterior lobe remnants through serial sections of the decalcified sella turcica 16 ; (b) Furthermore if sella turcica, pituitary stalk and hypothalamus are removed together and included in the same block one observes the great regenerative ability of hypophyseal portal vessels towards anterior lobe remnants and of anterior lobe cells themselves. This was described both after hypophysectomy and after pituitary stalk section. On the other hand as hypophysectomy may be dangerous and difficult owing to diffuse bleeding in severely ill patients with multiple metastasis, we use pituitary stalk section when at operation hypophysectomy seems hazardous for local conditions (short optic nerves and/or a bulging tuberculum sellae). If pituitary section is adopted it is therefore imperative to find a way to interrupt permanently any vascular connexion between the hypothalamus and the anterior lobe, in agreement with the experimental work of Harris 11 .(c) Finally, the extent of pituitary tissue necrosis after mischotomy (miskos, stalk; tomé, section) is a significant though variable factor 24 .We shall comment here some aspects of mischotomy under three headings: (1) Surgical technique and clinical results; (2) Anatomical and physiological observations; (3) Studies on normal pituitary tissue removed during the operation and examined by electron microscopy.