Clinical response to gastric peroral endoscopic myotomy and its association to changes in pyloric impedance planimetry measurements: a systematic review and meta-analysis

Abstract

Background and Aims Gastric peroral endoscopic myotomy (G-POEM) has emerged as a potential therapy for patients with medically refractory gastroparesis. Although adequate patient selection is crucial, there is a paucity of data on factors that may help select patients and predict a favorable response to G-POEM. Methods We performed a systematic review and meta-analysis to evaluate pyloric functional lumen imaging probe (FLIP) changes in patients undergoing G-POEM. Pre– and post–G-POEM data were collected and analyzed. Clinical response was defined as an improvement of at least 1 point in the mean overall Gastroparesis Cardinal Symptom Index (GCSI) score, consistent with criteria used across included studies. Standardized mean differences (SMDs) compared metrics between groups (responders vs nonresponders), and pooled success rates with 95% CIs were estimated with random-effects models, with heterogeneity assessed by I 2. Results Four studies involving 203 patients (76.7% women, mean age 55.2 years) were included in the final analysis. Overall, pooled clinical success and failure rates were 70.3% (95% CI, 63.5-76.3; I 2 = 0%) and 31.3% (95% CI, 25.3-38.3; I 2 = 0%), respectively. There were no differences between the responders versus nonresponders in baseline pyloric FLIP measurements. We found a statistically significant increase in the distensibility index after G-POEM in both groups. Conversely, pylorus cross-sectional area (CSA) improved significantly only among responders, 183.1 mm2 (163.8-202.5) versus 146.9 mm2 (125.1-168.8); SMD −0.71 (−0.99 to −0.43); P < .001; I 2 = 0% but not among nonresponders after G-POEM. Conclusions Our analysis shows that patients who responded to G-POEM had higher baseline GCSI scores than nonresponders. Post–G-POEM pylorus CSA was associated with clinical response. FLIP may provide an objective assessment of pyloric changes and be a potential tool to predict the clinical outcome of G-POEM. Additional studies with standardized FLIP protocols in patients undergoing G-POEM are needed.