Introduction: Peroral endoscopic myotomy (POEM) is an effective procedure that is used to treat esophageal achalasia. Early studies recommended a circular myotomy where the circular muscle layer is cut with preservation of the longitudinal layer. Recent studies have investigated full thickness myotomy as a possible alternative to treat severe cases.
Methods: We conducted a systematic review and meta-analysis on the studies that compared full thickness and circular POEM in treating achalasia patients. We performed a comprehensive search in the databases of PubMed/MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from inception through April 20th, 2022. We considered randomized controlled trials, cohort studies, case-control studies, and case series. We excluded abstracts, animal studies, case reports, reviews, editorials, and letters to editors. From each study, we collected the number of patients who underwent full thickness and circular POEM. The primary outcome was clinical success. The secondary outcomes were the occurrence of subcutaneous emphysema, operation time, and post-procedure reflux symptoms. The random-effects model was used to calculate the risk ratios (RR), mean differences (MD), and confidence intervals (CI). A p value < 0.05 was considered statistically significant. Heterogeneity was assessed using the Higgins I2 index.
Results: Six randomized controlled trials involving 774 patients were included in the meta-analysis. The rate of clinical success was not statistically different between full thickness and circular POEM (RR 1.02, 95% CI 0.98-1.06, p = 0.45, I2 = 0%) (Figure 1a). The rate of subcutaneous emphysema was significantly lower in the full thickness group (RR 0.62, 95% CI 0.43-0.89, p = 0.01, I2 = 0%) and the operation time was also lower in the same group (MD -10.60 mins, 95% CI -19.60- -2.13, p = 0.01, I2 = 76%) (Figure 1b and 1c). The rate of post-procedure reflux symptoms was not statistically different between the two groups (RR 1.10, 95% CI 0.60-2.02, p = 0.75, I2 = 22%).
Discussion: Our meta-analysis demonstrated that clinical success was not statistically different between full thickness and circular PEOM. However, subcutaneous emphysema and operation time were both significantly lower in the full thickness myotomy group. There was no difference between the two groups in the rate of post-procedure reflux symptoms. Further randomized controlled trials are needed to confirm our findings.
