The Role of Functional Lumen Imaging Probe (FLIP) in Addition to High-Resolution Manometry and Timed Barium...

A subgroup of treated achalasia patients has recurrent symptoms which prompt consideration of additional treatment. The aim of this study was to examine the additional yield of functional lumen imaging probe (FLIP) to high-resolution manometry (HRM) and timed barium esophagram (TBE) in selection of patients for retreatment.

This prospective observational cohort study was performed between November 2019 and October 2025 and included treated achalasia patients with recurrent or persistent symptoms who underwent FLIP in addition to HRM and TBE prior to retreatment. The primary outcome was the association between the distensibility index measured by FLIP and response to retreatment (treatment success: Eckardt score ≤ 3).

In total 84 patients were included (median age 50 years, 36.9% female). At a median follow-up of 11 weeks after retreatment, 82.1% had treatment success (N = 69/84) and 17.9% had treatment failure (N = 15/84). The distensibility index at 40 mL on FLIP did not significantly differ between patients with and without treatment success (1.4 mm²/mmHg vs. 1.0 mm²/mmHg, p = 0.463). Almost all patients with abnormal HRM and TBE results had treatment success (N = 22/23, 95.7%). In cases with inconclusive HRM and TBE results, treatment success was 83.3% when FLIP results were normal (N = 10/12) and 74.3% when FLIP results were abnormal (N = 26/35).

FLIP did not provide added value over HRM and TBE for identifying treated achalasia patients who may benefit from further treatment. The difficulty in selecting achalasia patients for retreatment highlights the complexity of this patient population and underscores the need for further research.