Outcome of endoscopic transsphenoidal surgery for acromegaly: Comparison of using and not using the floor standing pneumatic powered endoscope-holder system.

Introduction: Endoscopic transsphenoidal surgery can be performed by two surgeons, including an endoscopist (PE/2S), and by a single surgeon with an endoscope-holder system (PE/1S + H). We analyzed the surgical outcome, and outcome predictors in acromegaly patients in endoscopic transsphenoidal surgery using floor standing pneumatic endoscope-holder system. Methods: Endoscopic transsphenoidal surgery was performed with PE/1S+H (n = 51) and PE/2S (n = 20). Postoperative remission was evaluated by the 2010 consensus criteria for acromegaly. We compared the surgical results of PE/2S style and PE/1S+H style, and investigated the factors associated with favorable surgical outcomes. Results: There was no difference in clinical background between the PE/2S and the PE/1S + H groups. The remission rates for PE/2S and PE/1S+H were 65.0% and 82.4%, respectively, with no significant difference (p = 0.128). In consecutive 71 cases, statistically useful predictors of remission were low preoperative growth hormone (GH) level (<12 ng/mL), low Knosp grade (0-2), and low revised Knosp grade (0-3A). In the conventional Knosp grade 0-2 and 3/4, the sensitivity was 0.76 and the specificity was 0.81. In the revised Knosp grade 0-3A and 3B/4, the sensitivity was 0.96 and the specificity was 0.44. Conclusion: The outcome of GH-producing pituitary neuroendocrine tumors surgically removed by PE/1S+H could be almost equivalent to that by PE/2S. Preoperative low GH level and Knosp grades, including revised Knosp grades, are useful preoperative predictors for surgical remission of acromegaly.