Transphenoidal hypophysectomy is often carried out to remove ACTH-secreting tumours of the pituitary. A postoperative serum cortisol of <50nmol/l usually indicates cure of the disease but after other audits found persistent cases, 'remission' is thought to be a more appropriate term.
Charing Cross Hospital is the tertiary neurosurgical centre for West London where a single, dedicated pituitary surgeon was appointed in 1995. We analysed the success of every operation done from this time until December 2001 using <50 nmol/l as our definition of remission. As all operations were carried out by a single surgeon, the presence of a learning curve was also able to be analysed.
Transphenoidal hypophysectomy has been carried out in 130 patients in the time-period studied. Twenty of these were for ACTHomas. One set of patient's notes was unable to be found and so 19 patient notes were analysed: two males and 17 females (89.5% female predominance). A detailed study of all pre and post-operative clinical, biochemical and radiological information was carried out as well as information regarding the operation itself.
The overall remission rate for Cushing's disease was 73.6%. Seven patients (36.8%) had post-operative cortisols that reached this cut-off without LDDST. The five patients that failed underwent bilateral adrenalectomy. The success rate for each year was analysed and an r value of 0.72 indicates the presence of a learning curve (r2=0.51). One patient died within 1 week of surgery and one patient developed meningitis. No other serious complications were found. Mean hospital stay was 10 days. In the time period studied, no patients originally in remission ever experienced relapse.
The presence of a learning curve supports the view that surgery for Cushing's disease should be carried out in specialist centres and by specialised neurosurgeons.