Astafeva L., Kadashev B.
Burdenko Research Institute of Neurosurgery, Moscow, Russia
A “transacted” hypophyseal stalk (HS) is a medical term, which implies two states: HS compression by a mass or its transaction during an operation. Both cases are considered to result in reduction of hypothalamic control over secretion of pituitaryseal hormones. In its turn it leads to hyperprolactinemia and insufficient secretion of all pituitary hormones.
The reaesrch goal was to study a state, watched after forced HS transaction during operation.
Material and Methods. There were 50 cases with tumors of the chiasm-sella region (CSR), operated at the Institute of Neurosurgery in 1998-2005. The first group included 28 cases with stalk craniopharyngiomas, which destructed it almost completely. HS was transacted during operation. The pituitary gland was intact both before and after surgical intervention. The second group consisted of 11 patients with endosuprasellar pituitary adenomas. They compressed HS, which was transacted for performing resection of a suprasellar part of the capsule. The pituitary gland was characterized by certain changes both before and after operation. The third or comparative group was represented by 11 cases with suprasellar meningiomas. They compressed HS, which was preserved during operation. The pituitary gland was intact both before and after it.
Conclusions. HS transaction during operation led to development or aggravation of panhypopituitarism in all the cases and persistent diabetes insipidus in the majority of them (1). Removal of suprasellar meningiomas without HS transaction was not accompanied by augmentation of hypopituitary symptoms (2). HS compression before operation resulted in hyperprolactinemia in a one third of cases with tumors of the chiasm-sella region. Elimination of HS compression by meningiomas was accompanied by restoration of normal levels of prolactin in the majority of cases. We did not watch an expected growth of prolactin levels in blood after HS transaction in 60% of cases with craniopharyngiomas and 80% of patients with adenomas. At present the mechanism of this phenomenon is unclear and demands further study (3).