Pressure and blood flow in pituitary adenomas measured during transsphenoidal surgery.

In 48 patients undergoing transsphenoidal surgery for pituitary adenoma, the intrasellar pressure was recorded during surgery. In 14 patients, adenoma blood flow was measured with the technique of local injection of 133xenon. Median intrasellar pressure was 30 mmHg (range 8-62), n = 48, and median adenoma blood flow was 8 ml/100 g/min (range 0-37), n = 14. In two patients, blood flow in the anterior pituitary gland was measured, and values of 26 and 22 ml/100 g/min were obtained. The finding that intrasellar pressure is above central venous and intracranial pressure suggests the possibility that the adenoma and the anterior pituitary gland are supplied not only with venous blood, but receive an additional arterial supply at a less than normal arterial pressure. In three cases perfusion pressures that caused arrest of adenoma blood flow were found, and these observations are discussed with reference to pituitary apoplexy.