Acromegaly Support Group
Acromegaly (from Greek akros "high" and megas "large" - extremities enlargement) is a hormonal disorder that results when the pituitary gland produces excess growth hormone (hGH). Acromegaly most commonly affects middle-aged adults and can result in serious illness and premature death. Join the group to discuss symptoms, diagnosis, and treatments.
http://www.medscape.com/viewarticle/516043_4
which implies that rates of complication after pituitary surgery in Belfast (specifically in this case for Cushing's) are broadly reflective of wider experience.
It doesn't answer your question really, but implies that they would be, at the very least, no less capable than other pituitary centres.
The NHS is actually quite good at concentrating surgical expertise for rare diseases in regional centres.
John