Endoluminal Functional Lumen Imaging Probe in the Functional Assessment of Pyloric Sphincter in Gastroparesis: A...

The aim of this systematic review and meta-analysis was to investigate the role of EndoFLIP in gastroparesis, focusing on reference values of pyloric function and the effect of pylorus-targeted therapies.

A systematic search of major databases and conference proceedings was performed up to July 2025. Observational studies and RCTs reporting FLIP measurements in confirmed gastroparesis were included. Pooled baseline values, percentile distributions, and mean differences (MDs) pre- versus posttreatment were calculated. Heterogeneity was addressed with random effects models, sensitivity analyses, and meta-regression.

Twenty-three studies (N = 981 patients with gastroparesis) were included. Most were prospective cohorts or single-center studies, with G-POEM as the predominant intervention. The most assessed FLIP metrics were distensibility index (DI) and cross-sectional area (CSA). Three (out of 7) studies reported a positive correlation between DI and CSA with specific symptoms (dyspepsia spectrum and nausea/vomiting) and their severity at baseline. Thirteen out of 18 studies showed an association between FLIP parameters with clinical response while no robust link with gastric emptying emerged. Baseline pooled normative values at 40 mL distension were: DI 7.40 mm²/mmHg (5th-95th percentile: 2.5-25.4), CSA 129.6 mm² (51.3-249.7), D_min 13.2 mm (8.2-19.1), and P 17.8 mmHg (7.7-39.2). At 50 mL: DI 5.7 mm²/mmHg, CSA 191.9 mm², D_min 16.1 mm, and P 29.9 mmHg. After pyloric-targeted therapy, FLIP metrics improved significantly: DI increased at 40 mL (MD 3.5 mm²/mmHg, 95% CI 2.1-4.8; I² 57.3%) and at 50 mL (MD 1.7 mm²/mmHg, 95% CI -0.7 - +4.1; I² 61.1%); CSA increased at 40 mL (MD 42.3 mm², 95% CI 30.7-53.9; I² 13%) and 50 mL (MD 63.2 mm², 95% CI 41.3-85.1; I² 0%).

EndoFLIP provides reproducible pyloric functional metrics in gastroparesis. DI and CSA, particularly at 40-50 mL distension, are the most reliable parameters, improving consistently after pylorus-targeted therapies and reflecting clinical benefit. A DI of < 7-10 mm²/mmHg may represent a pragmatic threshold for impaired distensibility and a good target for treatment response.