VENOUS BLEEDING DURING TRANSSPHENOIDAL SURGERY - ITS ASSOCIATION WITHPREOPERATIVE AND INTRAOPERATIVE FACTORS AND WITH CAVERNOUS SINUS AND CENTRAL VENOUS PRESSURES

Venous bleeding during transsphenoidal surgery for resection of pituit ary tumors is a common problem that interferes with the performance of the surgical procedure. In this study, data were collected prospectiv ely from 50 patients to determine whether there were pre- or intraoper ative factors (e.g., patient demographics, type and grade of pituitary tumor, intraoperative hemodynamics) associated with venous bleeding w hich might be used to predict its occurrence. In addition, central ven ous pressure (CVP), and cavernous sinus pressure (CSP) were measured i n 13 patients to evaluate the relationship of these pressures to each other and to the severity of venous bleeding. During resection of the pituitary tumor, the severity of venous bleeding was graded as minimal , moderate, or severe, the latter two grades requiring therapeutic int ervention. Moderate bleeding requiring intervention occurred in 15 of the 50 patients, and resolved in all cases. Moderate bleeding was not related to CSP or CVP, and no specific associated factor was observed. CSP was not correlated with CVP, and was higher than that predicted f rom the CVP and the position of the patient or the hydrostatic gravita tional pressure gradient. These results suggest that it is not possibl e to predict in advance which patients will have problems with venous bleeding, but that simple therapeutic maneuvers are effective.