Endoscopic Transsphenoidal Surgery for Acromegaly

Abstract

Objective: The aim of this study was to determine the preoperative predictors of the extent of resection and endocrinological remission following endonasal endoscopic removal of growth hormone (GH) – secreting pituitary adenomas. Trans-sphenoidal surgery is the preferred treatment modality for growth hormone (GH) – secreting pituitary adenomas. In many series, the reported postoperative remission is based mainly on achieve-ment of GH levels less than 2 ng/ml. Strict criteria for insulin – like growth factor I normalization and even lower GH levels (< 1 ng/ml) are now suggested to define cure of acromegaly, but the evidence does not yet support such low GH levels in epidemiological follow-up. We analyzed our postoperative results in a sample of local popu-lation with acromegaly. Methods: Seven patients harboring GH – secreting adenomas (07 macroadenomas) underwent transsphenoidal surgery between 2005 and 2007 in Lahore General Hospital. The patient group included 03 women and 04 men of 23 – 50 years of age. All the patients were operated for the first time. Biochemical remission was defined as a repeated fasting or glucose – suppressed GH level of 2 ng/ml or less, and a normal insulin – like growth factor I level.
Results: The majority of acromegalic patients (83%) had macroadenomas > 1 cm in maximum diameter. Gross – total resection was achieved in 05 (71%) of 07 patients. Notably, endoscopic transsphenoidal surgery allowed complete resection of all lesions without cavernous sinus invasion, regardless of the suprasellar extent. Biochemical remission was achieved in 06 (85%) of 07 patients. A postoperative reduction in GH serum levels were associated with a higher rate of biochemical cure (p < 0.05). Significant differences were observed between pre- and postsurgical serum GH levels in male patients with Acromegalic tumors. Although mean serum GH concentrations were discernibly higher in patients as compared to controls (30.2 ± 3.1 vs 0.4 ± 0.1). In all the three premenopausal female patients included in the study, the individual presurgical serum GH levels were greater than those following surgery. The mean value was significantly higher than of the controls (38.9 ± 10.3 vs 0.2 ± 0.6 ng/ml, respectively).These values exceeded the normal serum GH concentrations described for healthy women (7 ng/ml or less). Following surgical removal of the adenoma, serum GH concentrations showed a marked decline of GH levels in all patients.
Conclusion: A purely endoscopic endonasal trans-sphenoidal adenoma resection leads to a high rate of gross – total tumor resection and endocrinological remission in acromegalic patients, even those harboring macro-adenomas with wide suprasellar extension. Extended approaches and angled endoscopes are useful tools for increasing the extent of resection.