gms | German Medical Science

Objective: Despite modern imaging and refined operation techniques a surgical cure of Cushing’s disease (CD) remains a challenge for the treating neurosurgeon. Surgical remission rates for patients with CD range between 50% - 85%. Up to 25% of all patients sustain recurrences. Our aim was to identify variables associated with positive vs. unfavorable outcomes with respect to drop in cortisol levels after surgery for CD in a single centre cohort.

Method: A consecutive series of 25 patients (19 females, 6 males) with biochemically confirmed central CD underwent endoscopic transsphenoidal surgery between October 2012 and September 2015. Diagnosis of Cushing’s disease was done by endocrinologist identifying ACTH excess in serum levels, petrosal sinus catheter sampling (n=20) and lesion detection in cranial MRI. Operation was deemed successful, if postoperative cortisol level dropped below 139nmol/l. Histopathological examination was assessed for confirmation of ACTH secreting tumors.

Results: In 19/25 cases (76%) post-surgical cortisol levels dropped below 139 nmol/l. One further patient exhibited a basal cortisol of 166 nmol/l postoperatively. In all of these patients the clinical symptoms of CD resolved and endocrinological follow-up investigations indicated disease remission. In none of the patients with postoperatively elevated cortisol levels, surgical cure was achieved, despite second look operations in 5/6. The sixth patient had biochemical disease recurrence after 1 year and underwent unsuccessful repeat surgery in another department. Histology confirmed ACTH-immunostaining adenoma in 15/25 patients. In patients with a missing drop in postoperative cortisol levels, histology was negative in 80% and there was no clear lesion visible on MRI. In patients with a clear difference of cortisol and ACTH levels in right- vs. left-sided petrosal sinus sampling a rapid cortisol decline post-surgery was observed frequently (17/19; 89.5%).

Conclusions: Endoscopic transsphenoidal surgery for Cushing’s disease can be done with a high success rate. From our data, we suggest that the main factors associated with unsuccessful surgery are no visible lesion on preoperative MRI and a missing lateralization in petrosal sinus sampling. If suppression of cortisol excess was not achieved primarily, second look operation may control disease in about one third of the cases, only. Previous operations are a negative predictor for a successful postoperative disease control.