Outcome of transphenoidal surgery for acromegaly and its relationship to surgical experience

BACKGROUND A number of surgical series have been reported on the treatment of acromegaly and their results vary widely. The acceptable definition of r emission has changed in recent years and it is known, though in a small ser ies, that growth hormone levels of >5 mU/I are still associated with an inc reased mortality from the condition. We have analysed data at this centre a nd examined the outcome of transphenoidal surgery for acromegaly, compared our results with recently published series from other centres and also asse ssed factors which might effect outcome including whether there is any demo nstrable effect of the experience of the surgeon on outcome. PATIENTS AND METHODS We have analysed data from all of our 139 patients in whom follow up data are available who have undergone initial transphenoidal surgery for acromegaly by one surgeon at this centre, between 1974 and 199 5, Follow up was for a median of 5 years (range 1 month to 17 years). RESUL TS 67% of patients achieved the criterion for remission (mean GH <5 mU/I), Success was related to tumour size and preoperative growth hormone values. Thus 91% of patients with microadenomas were in remission postoperatively c ompared to 46% of patients with macroadenomas. Analysis of the results acco rding to the year of operation showed an improvement in success rates with time. More than 15 years ago, the success rate according to the growth horm one criteria set was 48% and the failure rate 52%, In contrast in the last 5 years analysed, the overall success rate was 74% with a failure rate of 2 6% (P<0.04). The success rate for microadenomas was 50% initially, then rem ained 100%, The case mix was analysed and no change was found. We have also demonstrated an improvement in pituitary function (including n ormalization of preoperative elevated prolactin) with time so that pre 1981 16% of patients' pituitary function improved perioperatively but 10 years later this figure had risen to 34% (P<0.03). There was no change over time in the development of pituitary hypofunction, complication rate or recurren ce rate, CONCLUSION Surgical treatment is a safe and effective treatment for acromeg aly and remains the first choice of treatment for most acromegalic patients . The results of this centre compare favourably with series from other cent res, We have demonstrated improved results, both in terms of post operative growth hormone values and pituitary function tests with time and increasin g neurosurgical experience. We conclude that outcome for the surgical treat ment for acromegaly is best achieved with one surgeon specialising in pitui tary surgery. Improved operative outcome thus achieved has major cost impli cations and avoids the necessity for consideration of postoperative radioth erapy and the use of expensive growth hormone suppressing drugs in the post operative period.