Achieving physiologic distensibility targets frequently requires modification of standard cruroplasty during anti-reflux surgery

Abstract Background Intraoperative EndoFLIP provides objective assessment of esophagogastric junction (EGJ) distensibility during anti-reflux surgery, and final distensibility index (DI) values of 2.0–3.5 mm 2 /mmHg have been associated with improved reflux control while minimizing dysphagia and gas bloat. However, the operative modifications needed to achieve these targets in real time remain poorly defined. We evaluated how a standardized EndoFLIP protocol alters intraoperative decision-making during robotic hiatal hernia repair and identified which operative components most influence EGJ distensibility. Methods A prospective observational cohort study included consecutive patients undergoing robotic hiatal hernia repair with fundoplication or magnetic sphincter augmentation (MSA) by a single foregut surgeon (October 2024–October 2025). EndoFLIP measurements were obtained after dissection (T1), after cruroplasty (T2), and after fundoplication or MSA (T3) at a standardized 40 mL fill without pneumoperitoneum. A target final DI of 2.0–3.5 mm 2 /mmHg was applied; the cruroplasty was modified when T2 predicted a final post-procedure DI outside this range. Results Forty patients were included. Mean DI decreased from 6.46 ± 3.27 mm 2 /mmHg at T1 to 2.98 ± 0.97 at T2 and 2.22 ± 0.46 at T3. Cruroplasty accounted for 82.1% of the total intraoperative reduction in EGJ distensibility. EndoFLIP-guided cruroplasty modification was required in 10 patients (25.0%): suture addition ( n =5), removal ( n =4), and removal followed by replacement ( n =1). Several modifications were performed despite T2 values within the nominal target range, anticipating further distensibility reduction after fundoplication. Conclusion Objective physiologic calibration with EndoFLIP frequently altered standard hiatal closure technique, even in experienced hands. The cruroplasty, rather than the fundoplication, accounted for the majority of intraoperative change in EGJ distensibility and was the principal modifiable determinant of final physiology. Subjective calibration may inadequately predict final EGJ distensibility, and physiologic measurement may be necessary to optimize anti-reflux repair.