Clinical Outcomes Of Peroral Endoscopic Myotomy(POEM) For Esophageal Diseases:A Series Of Meta-analyses

Objective:With the development of super minimally invasive endoscopic surgery,peroral endoscopic myotomy(POEM)and its derivatives,such as Zenker’s peroral endoscopic myotomy(Z-POEM),are becoming more and more widely used in esophageal diseases.Recently,more and more clinical studies have been conducted on the efficacy of POEM and its derived operation for treating esophageal diseases,such as achalasia(AC)and Zenker’s diverticulum(ZD).We aimed to conducted a series of meta-analyses from three aspects:the mid-term and long-term efficacy and safety of POEM for the treatment of AC,the comparative efficacy of peroral endoscopic shorter myotomy(SM)versus longer myotomy(LM)for the treatment of AC,and the safety and efficacy of Z-POEM for the treatment of ZD.The overall effects of POEM for esophageal diseases were summarized to provide evidence-based medical evidence for clinical practice.Methods:Studies relevant to POEM for the treatment of AC and ZD were comprehensively searched by computer from four databases,including Pub Med,Embase,Web of Sciencea,and Cochrane Library.Literature screening,data extraction,and quality evaluation were conducted by two independent reviewers according to the pre-designed inclusion and exclusion criteria.Finally,Comprehensive Meta-Analysis 3.0 software and Cochrane Review Manager 5.3 software were used for statistical analysis.Results:Part 1 Mid-term and long-term outcomes of POEM for the treatment of AC:a meta-analysisThis section included a total of 21 studies,involving 2698patients with AC.Overall,the pooled clinical success rates with 2-,3-,4-,and 5-years follow-ups were 91.3%(95%Confidence interval[CI]88.4–93.6%;I~2=64.321%),90.4%(95%CI 88.1–92.2%;I~2=24.312%),89.8%(95%CI 83.6–93.9%;I~2=55.904%),and 82.2%(95%CI76.6–86.7%;I~2=0%),respectively.Moreover,the pooled incidence of symptomatic refux and refux esophagitis were 23.9%(95%CI18.7–29.9%;I~2=78.803%)and 16.7%(95%CI 11.9–23.1%;I~2=78.905%),respectively.Besides,the pooled long-term clinical success rates for type I,II,and III achalasia were 86.1%(95%CI 80.9–90.1%;I~2=0%),87.9%(95%CI 84.2–90.8%;I~2=48.354%),and 83.9%(95%CI72.5–91.2%;I~2=0%),respectively.Part 2 Safety and efficacy of SM versus LM for patients with AC:a meta-analysisThis section included a total of five studies,involving 225patients in SM group and 222 patients in LM group.The pooled clinical success and technical success rates of SM were 96.6%(95%CI 92.7–98.4%;I~2=0%)and 98.9%(95%CI 96.2%–99.7%;I~2=0%).Post-POEM Eckardt score,lower esophageal sphincter pressure(LESP),and 4s-integrated relaxation pressure(IRP)in SM group were significantly improved(Mean difference[MD]6.07,95%CI 5.34–6.20;MD 18.82,95%CI 13.58–24.05;MD 13.49,95%CI 12.10–14.87).Compared with LM group,SM group significantly reduced the operation time(MD-16.30,95%CI-23.10–-9.49)and the incidence of abnormal acid reflux based on p H monitoring(Relative risk[RR]0.58,95%CI 0.36–0.94).There was no significant difference between SM group and LM group in clinical success rate,the length of hospital stay,post-POEM Eckardt score,post-POEM LESP,post-POEM IRP,and the incidence of symptomatic reflux and reflux esophagitis.Part 3 The role of Z-POEM for ZD:a meta-analysisThis section included a total of 11 studies,involving 357patients treated with Z-POEM.Six studies compared 244 patients treated with Z-POEM and 289 patients treated with flexible endoscopic septotomy(FES).The pooled clinical success rate,technical success rate,incidence of adverse events,and clinical recurrence rate of Z-POEM for the treatment of ZD were 93.0%(95%CI 89.4–95.4%;I~2=0%),96.3%(95%CI 93.6–97.9%;I~2=0%),12.4%(95%CI 9.1–16.7%;I~2=0%),and 11.2%(95%CI 7.6–16.2%;I~2=0%).In terms of clinical success rate,Z-POEM was superior to FES(RR 1.11,95%CI 1.03–1.18;P=0.004,I~2=0%).There was no statistically significant difference between Z-POEM and FES in technical success rate,clinical recurrence rate,incidence of adverse events,operation time,and the length of hospital stay.Conclusion:1 POEM is a safe and effective modality for the treatment of achalasia,with a long-term clinical success rate of 82.2%during5-year follow-up.2 SM and LM are comparable in providing treatment efficacy for AC,while less operation time and lower incidence of post-POEM abnormal esophageal acid exposure are observed in SM group.3 Z-POEM is a safe and effective modality for the treatment of Zenker’s diverticulum,and the clinical success rate is better than FES.