LONG-TERM ENDOCRINOLOGIC FOLLOW-UP EVALUATION IN 115 PATIENTS WHO UNDERWENT TRANSSPHENOIDAL SURGERY FOR ACROMEGALY

Object. The results of surgical therapy for acromegaly were assessed u sing carefully conducted endocrinological testing in 115 patients who underwent transsphenoidal surgery from 1981 to 1995. Methods. Ninety-n ine of the 115 patients could be contacted for follow-up review; in 57 of the patients an endocrinological assessment was performed by the a uthors. Biochemical cure was strictly defined as a normalization of th e insulin-like growth factor(IGF)-I level (obtained in 100 patients) a nd/or a basal or glucose-suppressed growth hormone (GH) level of 2 ng/ ml or less. The mean length of follow up from transsphenoidal surgery to laboratory testing was 5.4 years with a maximum of 15.7 years. Afte r transsphenoidal surgery alone, 61% of the patients achieved a bioche mical remission; the remission rate was 88% for patients with microade nomas and 53% for those with macroadenomas. Tumor size and preoperativ e GH level tended to correlate negatively with outcome of surgery. Ear ly postoperative GH level tended to correlate with long-term outcome; in cases in which the early postoperative GH level was lower than 3 ng /ml, the chance of long-term remission was 89%. Thirty-two patients re ceived postoperative radiotherapy: in 10 (31%) of these patients the d isease is currently in remission after surgery and radiotherapy only a nd in three others the disease is in remission with the addition of me dical therapy. The over all complication rate was 6.9% with no cerebro spinal fluid leaks, meningitis, permanent diabetes insipidus, or new h ypopituitarism. The overall recurrence rate was low at 5.4%. Conclusio ns. This series shows, based on IFGF-I measurements and strict GH supr ession criteria to define remission, that transsphenoidal surgery prov ides an excellent chance for long-term cure in patients with microaden omas. Surgery alone is successful in most patients with noninvasive ma croadenomas; however, most patients with invasive macroadenomas will r equire adjunctive therapy. Recurrences are uncommon when biochemical r emission is clearly documented postoperatively.