Evaluation of trans-sphenoidal surgery in pituitary GH-secreting micro- and macroadenomas: a comparison between microsurgical and endoscopic approach.

Aim: Acromegaly is caused by a GH-secreting pituitary adenoma, associated with many comorbidities and increased risk of mortality. Surgery is the first-line therapy. Success of therapy is measured by symptomatic improvement, preservation of pituitary function and biochemical control. Trans-sphenoidal surgery (TSS), endoscopic or microscopic, is the preferred treatment. To evaluate surgery effectiveness and individuate the technique associated with a higher remission rate, patients undergoing TSS were retrospectively selected.

Methods: Thirty-seven consecutive patients underwent surgery between 1996 and 2006. Tumors were classified into macroadenomas or microadenomas and into intrasellar, extrasellar and extrasellar with cavernous sinus invasion. Surgery was performed in 22 patients with endoscopic technique, in 15 patients with microsurgical approach. The hormonal assays were performed 6 months and yearly after surgery for an average of 5 years.

Results: Ten patients were affected by microadenoma, 27 by macroadenoma. In microadenomas remission rate was independent of the used technique. Within macroadenomas, remission percentage in endoscopic approach (68.75%) was significantly higher than in microscopic approach (18.18%) (P=0.018). Postsurgical biochemical remission was calculated combining the surgical technique and tumor extension: the endoscopic approach was associated with a significantly higher remission rate in extrasellar than both in intrasellar and extrasellar with cavernous sinus invasion. In the latter group, any technique had not reached biochemical remission.

Conclusion: TSS is able to induce a long-term remission of acromegaly, with low risk of recurrence and complications. Endoscopic approach is more suitable than microscopic technique in macroadenomas and adenomas with suprasellar extension.