Objective: Transsphenoidal selective adenomectomy (TSA) is widely accepted as the treatment of choice for Cushing's disease but not all patients are cured by this procedure. The success of surgery depends on the skill and experience of the surgeon but the criteria used to define remission are highly variable. We have analysed the outcome following surgery in our centre using the stringent requirement of a postoperative serum cortisol of < 50 nmol/l as our definition of remission and assessed whether changes in surgical policy, including a greater emphasis on selective procedures and the move in recent years to a single surgeon undertaking all pituitary surgery, have improved complication and remission rates.
Patients and methods: The case notes, histology and pituitary imaging of 54 consecutive patients (42 females, mean age 41 years) with pituitary-dependent Cushing's syndrome who had undergone transsphenoidal surgery between January 1980 and November 2000 were reviewed. Follow-up was for a median of 6 years (range 6 months to 21 years).
Results: One patient died within 1 week of surgery (1.9%) and major morbidity occurred in eight patients (15%). Clinical and biochemical remission was achieved in 41 patients (77%) with only two recurrences (5%) to date. Success was related to tumour size with 37 (86%) of 43 intrasellar lesions successfully resected compared with only four (40%) of 10 extrasellar adenomas. Twenty-four (59%) of those in remission developed partial or complete hypopituitarism compared with four (33%) of those not in remission. The extent of surgical exploration predicted the development of hypopituitarism (88% total hypophysectomy, 33% hemihypophysectomy, 14% selective adenomectomy) but not remission (75% total hypophysectomy, 87% hemihypophysectomy, 71% selective adenomectomy). Among complications, an excess of venous thromboembolic disease was noted, with three patients (6%) developing deep venous thrombosis or pulmonary embolism postoperatively. Comparison of the data for individual surgeons revealed an improvement in outcome over time, with 100% remission of microadenomas, 29% hypopituitarism and 12% complications following the move to a single surgeon undertaking all pituitary surgery.
Conclusion: Transsphenoidal surgery is a safe and effective treatment for Cushing's disease and our results compare favourably with those from published series, the majority of which comprise relatively small numbers. The presence of an intrasellar lesion and postoperative serum cortisol < 50 nmol/l are good predictors of remission in the long term but historically in our centre this can only be achieved in a significant number of patients at the expense of some degree of hypopituitarism. However, the surgical outcome for Cushing's disease, including a reduced frequency of hypopituitarism, can be improved if patients are operated on by a single pituitary surgeon, using selective adenomectomy as the preferred surgical approach wherever possible.