Introduction: While cavernous sinus invasion has traditionally been considered a limiting factor for surgical cure of GH-secreting pituitary adenomas, endoscopy has potentially improved outcomes. We aimed to determine factors influencing outcome following endoscopic transsphenoidal surgery for acromegaly.
Methods: Acromegalic patients undergoing endoscopic transsphenoidal surgery by a single surgeon (ANM) were identified by retrospective review of our pituitary database. Tumor volumes were calculated from coronal gadolinium-enhanced MRIs (2-3 mm slice thickness) using the “closed polygon” algorithm of DICOM software (Osirix). Cavernous sinus invasion was measured in Knosp (K) scores by inspection of coronal images. Pre-operative IGF-1 and basal (bGH) and nadir (nGH) growth hormone levels during OGTT were recorded. Remission was based on post-operative criteria of normal IGF-1 and nGH < 0.4ng/ml. Data was subjected to multivariate analysis using ANOVA and univariate comparison to outcome (SPSS software).
Results: 50 patients underwent surgery for acromegaly between 2006 and 2012, with long-term follow-up available in 46 patients. Remission occurred in 36 (78%) patients with follow-up of up to 7 years (mean 3.7 years). Age at diagnosis significantly predicted post-operative remission, with older patients more often cured (mean age 52.6 years vs. 37.9 years; p=0.002). Neither smaller tumor volume nor lower K-score correlated with remission, indicating that endoscopic removal may be more effective for larger and more invasive tumors than microscopic methods. There was no relationship between pre-operative IGF-1, bGH, or nGH and remission.
Conclusions: Endoscopic transsphenoidal surgery yields high surgical cure rate (78%). There was no correlation between tumor volume and surgical cure, and little impact of cavernous sinus invasion. When compared to published data, these results suggest that endoscopy yields better outcomes than microscopy for acromegaly. K-score did not predict pre-operative GH or IGF-1 levels, suggesting that cavernous invasion does not directly influence serum measures of these values.
Patient Care: By shedding light on the utility of endoscopy over traditional microsurgical techniques for transsphenoidal resection of pituitary lesions in acromegalic patients.
Learning Objectives: By the conclusion of this session, participants should be able to determine factors that influence outcome following endoscopic transsphenoidal surgery in acromegalic patients