Posterior Peroral Endoscopic Myotomy With Versus Without Sparing of the Oblique/Sling Fibers: A Meta-analysis.

Background and aims: Several studies have hypothesized that sparing the oblique/sling fibers during posterior peroral endoscopic myotomy (POEM) may reduce the incidence of gastroesophageal reflux disease (GERD) and reflux esophagitis without compromising the established safety and efficacy of the procedure. This study compares perioperative, postoperative motility-related, and postoperative GERD-related outcomes between posterior oblique/sling fibers-sparing POEM (OFS-POEM) and conventional posterior POEM through a pairwise meta-analysis of comparative studies.

Methods: We conducted a systematic literature review following PRISMA guidelines to identify articles directly comparing posterior OFS-POEM with conventional posterior POEM. A pairwise meta-analysis was performed using a random-effects model. Effect sizes were calculated as odds ratios for dichotomous data and mean differences for continuous data.

Results: No significant differences were observed in perioperative outcomes, including mean gastric myotomy length, mean operative time, and incidence of adverse events. Similarly, no significant differences were noted in postoperative motility-related outcomes, such as mean Eckardt score and mean integrated relaxation pressure. However, a statistically significant reduction in the incidence of symptomatic GERD was observed in favor of OFS-POEM, with a number needed to treat (NNT) of 10 (95% CI: 6-49). Interestingly, no significant differences were found in the incidence of objectively diagnosed postoperative GERD, such as the number of patients with DeMeester scores >14 or the incidence of reflux esophagitis.

Conclusions: This study suggests that OFS-POEM may reduce the incidence of symptomatic GERD following POEM, without affecting the incidence of GERD diagnosed by pH studies (DeMeester score >14) or by endoscopy (reflux esophagitis). Future studies with larger sample sizes are needed to further investigate the impact of OFS-POEM on GERD incidence as determined by pH studies and endoscopic findings. Given the limitations of this study, no definitive conclusions can be drawn. Multicenter randomized controlled trials with larger sample sizes are required to reach more reliable conclusions. Furthermore, stratifying data according to the type and class of achalasia would provide valuable information on whether there are differences in outcomes among the various types and classes of achalasia.