Gastric emptying (GE) is involved in the regulation of appetite. We compared times of GE after different bariatric endoscopic and surgical interventions and associations with weight loss.

We performed a comprehensive search of publication databases, through September 14, 2018, for randomized and nonrandomized studies reporting outcomes of weight-loss surgeries. Two independent reviewers selected and appraised studies. The outcome of interest was GE T_1/2 (min), measured before and after the procedure. A random-effects model was used to pool the mean change in T_1/2 (min) after the intervention. We performed a meta-regression analysis to find associations between GE and weight loss. Heterogeneity was calculated using the I² statistic. Methodologic quality was assessed.

From 762 citations, the following studies were included in our analysis: 9 sleeve gastrectomies, 5 intragastric balloons, and 5 antral botulinum toxins. After sleeve gastrectomy, the pooled mean reduction in GE T_1/2 at 3 months was 29.2 minutes (95% CI, 40.9–17.5 min; I² = 91%). Fluid-filled balloons increased GE T_1/2 by 116 minutes (95% CI, 29.4–203.4 min; I² = 58.6%). Air-filled balloons did not produce a statistically significant difference in GE T_1/2. Antral botulinum injections increased GE T_1/2 by 9.6 minutes (95% CI, 2.8–16.4 min; I² = 13.3%). Placebo interventions reduced GE T_1/2 by 6.3 minutes (95% CI, 10-2.6 min). Changes in GE were associated with weight loss after sleeve gastrectomy and intragastric balloons, but not botulinum toxin injections.

In a systematic review and meta-analysis, we found that sleeve gastrectomy reduced GE T_1/2 whereas fluid-filled balloons significantly increased GE T_1/2. Air-filled balloons do not significantly change the time of GE, which could account for their low efficacy. Antral botulinum toxin injections produced small temporary increases in GE time, which were not associated with weight loss. Changes in GE time after surgical and endoscopic bariatric interventions correlated with weight loss and might be used to select interventions, based on patients’ physiology.