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Updated: Jan 7, 2026
Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas
Published on: January 17, 2018
Early Postoperative Predictors of Remission After Transsphenoidal Surgery in Acromegaly: Introduction of the PARS
Daisuke Tanioka1, Ikuya Natori1, Yusuke Kobayashi1
1Department of Neurosurgery, Showa Medical University School of Medicine, Tokyo 142-8666, Japan.
Context:
Endoscopic endonasal transsphenoidal surgery (EETS) is the standard treatment for acromegaly. However, reliable early markers to predict long-term biochemical remission remain unclear.
Objective:
This study retrospectively assesses the efficacy of EETS in acromegaly and investigates whether early postoperative hormone levels can independently predict biochemical remission. We also aimed to propose a simple clinical scoring system to facilitate early postoperative decision-making.
Methods:
We retrospectively analyzed 93 patients with acromegaly who underwent first-time EETS at a single center between 2005 and 2024. Serum growth hormone (GH) was measured on postoperative day (POD) 1, and insulin-like growth factor-1 (IGF-1) was assessed 3 months after surgery, expressed as SD scores. Biochemical remission was defined as nadir GH less than 0.4 ng/mL during oral glucose tolerance testing and age-adjusted IGF-1 within the normal range. Multivariable logistic regression and receiver operating characteristic (ROC) curve analysis were performed to identify and validate independent predictors of remission.
Results:
Of 93 patients, 79 (84.9%) achieved biochemical remission. Multivariable analysis identified POD1 GH (cutoff: 1.59 ng/mL, AUC: 0.89) and 3-month IGF-1 SD score (cutoff: +1.8, AUC: 0.98) as independent predictors. Based on these factors, we developed a simple risk score-the Postoperative Acromegaly Remission Score (PARS)-which stratifies patients by remission probability. Patients with low PARS values showed remission rates of 100%, whereas those with high scores showed significantly lower remission rates.
Conclusion:
Early postoperative GH and 3-month IGF-1 SD scores contribute to prognostication of long-term biochemical remission after EETS, and while structural determinants provide strong prognostic effect when early structural certainty is high, PARS may serve as a simple supportive framework when such certainty is insufficient or remains borderline.
