Long-term Results After Microsurgery for Cushing Disease: Experience with 426 Primary Operations over 35 Years

Objectives: The aim of this paper was to demonstrate the long-term results following microsurgery in a single surgeon's continuous series of patients with Cushing disease (CD), to assess the influence of changes in surgical procedures, and to compare the results with those of other treatment modalities. In particular, preoperative diagnosis, tumor size, results of histological examination, and complications were considered.

Methods: Between 1971 and 2004, 426 patients suffering from newly diagnosed CD underwent primary surgery. Pre-operative measures included clinical examination, endocrinological workup (testing of the hypothalamic-pituitary-adrenal axis, and 2- and 8-mg dexamethasone overnight suppression tests), sellar imaging (polytomography, computed tomography, and magnetic resonance [MR] imaging), and in patients with negative results on imaging studies, inferior petrosal sinus sampling. Follow-up examinations consisting of endocrinological workup, and imaging took place 1 week and 3 months after surgery and then at yearly intervals.

Results: During microsurgery as first treatment, the adenoma finding rate was 86.6%. After selective adenomectomy, the remission rate was 75.9%, and this rate showed no improvement over the years. The best results were achieved in microadenomas confirmed on MR imaging or histopathological investigation. The recurrence rate (15%) and the complication rate (5.9%) declined over the years. If no adenoma was found, exploration of the sella turcica was performed in 45.6%, hypophysectomy in 3.5%, and hemihypophysectomy in 50.9% of these patients, leading to an early remission in 37.9%. In case of persistence or recurrence, further treatment (repeated operation, adrenalectomy, radio-therapy, or medical treatment) was used to control the disease.

Conclusions: Microsurgery remains the treatment of first choice in CD, even though no improvement in remission rates was observed over the years, because complication or remission rates for other treatment options are comparable or worse.