Aims The selection of the optimal patient to undergo invasive treatments is one of the
major challenges in refractory gastroparesis. The aim of this systematic review was
to investigate the role of FLIP in gastroparesis. Meta analysis of normative values
and treatment comparative outcomes was also performed.
Methods A systematic search was performed until May 2024 on 3 major databases. Studies on
post-oncological/bariatric surgery gastroparesis were excluded. Pooled baseline mean
of FLIP metrics and mean differences (MDs) pre vs post-treatment were calculated to
provide normative values and to assess treatment effect. Random effects meta-analysis
with I2 statistics and subgroup analysis to address heterogeneity were performed.
Results Twenty studies (N=805 patients) were included. The majority focused on treatment
response, particularly pyloromyotomy (GPOEM). The most assessed FLIP metrics were
distensibility index (DI) and cross-sectional area (CSA). Three studies reported a
positive correlation between DI and CSA with specific symptoms (dyspepsia spectrum
and nausea/vomiting) and their severity at baseline. Ten studies showed an association
between FLIP parameters with clinical response but not with gastric emptying. Baseline
DI at 30 mL (7.5 mm2/mmHg; I2 38%) and CSA at 30 mL (85.5 mm2; I2 0%) yielded the lowest heterogeneity. Comparing pre- and post-treatment response,
MD of 2.5 mm2/mmHg (I2 24%) for DI at 50 mL, 46.7 mm2 (I2 47%) and 68.8 mm2 (I2 0%) for CSA at 40 and 50 mL respectively, resulted statistically significant.
Conclusions This is the first systematic effort in gathering evidence on FLIP in gastroparesis.
CSA and DI significantly changed after pylorus-targeted treatments. Normative values
displayed substantial heterogeneity. Further studies to develop and validate models
of response prediction are warranted before implementing this technique in routine
clinical care.
