Serum cortisol response to transsphenoidal surgery for Gushing disease

Object. Transsphenoidal surgery remains the optimal treatment for Gushing d isease, but the definitions of surgical cure and failure remain debatable. In this study the authors evaluated serum cortisol levels in patients befor e and after they underwent transsphenoidal surgery to elucidate the pattern s of cortisol decrease and the optimal time and criteria for determining su rgically induced remission. Methods. Twenty-seven patients were evaluated throughout an 8-month period. Serum cortisol levels were obtained before surgery and at 6-hour intervals postoperatively. No exogenous steroid medications were administered until after cortisol sampling was discontinued, following diagnosis of remission. Twenty-one (78%) of 27 cases were labeled initial surgically induced remiss ions. Twenty-two (81%) of 27 cases were deemed surgically induced remission s at follow-up examination. Following surgery, initial remissions and failu res demonstrated divergent patterns of cortisol levels. No patient whose co ndition was deemed an initial surgically induced remission has experienced definitive relapse of disease since discharge. One patient whose condition was initially deemed a surgical failure, eventually was found to exhibit su rgically induced remission without further intervention. Conclusions. Given such findings, exogenous steroid medications do not appe ar to be required for patients until after the determination of remission. During the Ist postoperative day, there is a time period during which serum cortisol values significantly differ between the categories of surgically induced remissions and surgical failures. Surgically induced remissions wer e identified when postoperative values of cortisol were lower than preopera tive midnight levels and when absolute values of cortisol were less than 10 mug/dl. In a small proportion of patients remission on a delayed basis may also be demonstrated. These data allow for a simple and rapid determinatio n of postoperative remission in patients undergoing transsphenoidal surgery for Gushing disease.