Introduction
The esophageal functional luminal imaging probe (FLIP) enables real-time measurement of esophagogastric junction (EGJ) dimensions and pressures during dilation. While FLIP metrics have been shown to predict outcomes after pneumatic dilation and myotomy, their predictive value following EsoFLIP dilation has not been established.
Aims & Methods
This study aimed to identify the FLIP measurements that best predict short-term clinical outcomes after single-session EsoFLIP dilation in patients with achalasia. In this single-center study, we analyzed data from treatment-naïve patients with achalasia undergoing EsoFLIP dilation between 2017 and 2025. Following the Dallas Consensus protocol, EGJ diameter (EGJ-Dia) and cross-sectional area (EGJ-CSA) were measured at 70 ml fill volume, and distensibility index (EGJ-DI) and balloon pressure (EGJ-BP) at 60 ml, both before and after dilation. Symptomatic response was defined as an Eckardt score (ES) ≤1 at 4 weeks post-dilation and served as the primary endpoint for assessing predictive performance of FLIP metrics. Objective response was defined as barium column height <5 cm at 5 minutes on timed barium esophagogram (TBE).
Results
Eighty-three patients (37% female; achalasia type 1 [n=7], type 2[n=71], type 3 [n=5]; mean age 53 years) were included. Short-term symptomatic response was achieved in 43% (36/83) and objective response in 57% (47/83). Median ES decreased from 6 (IQR 4-7) to 2 (IQR 0-4) post-dilation, and median TBE barium column height from 5 cm (IQR 3-7) to 2 cm (IQR 0-7). Median EGJ-Dia increased from 10 mm (IQR 8-11) to 17 mm (IQR 15-18, p < 0.001), EGJ-CSA from 72 mm² (IQR 48-99) to 214 mm² (IQR 178-253, p < 0.001), and EGJ-DI from 1 mm²/mmHg (IQR 1-2) to 6 mm²/mmHg (IQR 4-8, p < 0.001). Median EGJ-BP decreased from 31 kPa (IQR 23-38) to 23 kPa (IQR 20-29, p < 0.001). Among 51 patients with complete data, within-subject changes in EGJ-Dia70 and EGJ-CSA70 demonstrated the highest predictive performance for symptomatic response, with AUROCs of 0.77 (95% CI 0.63-0.91) and 0.75 (95% CI 0.60-0.90), respectively. Cut-offs of ΔEGJ-Dia ≥6.3 mm and ΔEGJ-CSA ≥129.3 mm² predicted clinical response with sensitivities/specificities of 0.80/0.47 and 0.80/0.61, respectively. ΔEGJ-DI60 showed moderate discriminative performance (AUROC 0.65), while ΔBP60 demonstrated no meaningful discriminative ability (AUROC 0.45).
Conclusion
Single-session EsoFLIP dilation resulted in significant improvement in both subjective and objective measures of EGJ function. Within-subject changes in FLIP metrics, particularly ΔEGJ-Dia and ΔEGJ-CSA, were predictive of symptomatic response while absolute postinterventional values were not meaningfully discriminative. These findings support the use of intra-procedural FLIP panometry for real-time assessment of treatment adequacy during EsoFLIP dilation.
References
Wu P, Szczesniak M, Craig P, Choo L, Engelman J, Terkasher B, et al. Novel intra-procedural distensibility measurement accurately predicts immediate outcome of pneumatic dilatation for idiopathic achalasia. Official journal of the American College of Gastroenterology| ACG. 2018;113(2):205–12.
Iqbal U, Yodice M, Ahmed Z, Anwar H, Arif SF, Lee-Smith WM, et al. Safety and efficacy of EsoFLIP dilation in patients with esophageal dysmotility: a systematic review. Dis Esophagus. 2024;37(8).
Schnurre L, Murray FR, Schindler V, Runggaldier D, Fischbach L, Bordier V, et al. Short-term outcome after singular hydraulic EsoFLIP dilation in patients with achalasia: A feasibility study. Neurogastroenterol Motil. 2020;32(9):e13864.
