Myotomy of Distal Esophagus Influences Proximal Esophageal Contraction and Upper Esophageal Sphincter Relaxation in Patients with Achalasia After Peroral Endoscopic Myotomy

BACKGROUND/AIMS: The motility change after peroral endoscopic myotomy (POEM) in achalasia is currently focused on lower esophageal sphincter (LES). This study aims to investigate the correlation of motility response between distal and proximal esophagus after POEM. METHODS: A total of 32 achalasia patients who received POEM and high-resolution manometry (HRM) were included for analysis. Eckardt score was used to assess symptom improvement. HRM was applied for studying motility. Main parameters analyzed were (1) LES: resting pressure (restP), 4-second integrated relaxation pressure; (2) esophageal body (EB): contractile integral of distal segment with myotomy (CI-DM) and proximal segment without myotomy (CI-PNM); and (3) upper esophageal sphincter (UES): relaxation pressure (UES-RP). RESULTS: There were 6 type I, 17 type II, and 9 type III achalasia patients included for analysis. (1) Eckardt score, LES tone, CI-DM, CI-PNM and UES-RP were reduced remarkably after POEM (P < 0.001). (2) no significant correlation was noted between LES tone and contractile intergral of EB. (3) a positive linear correlation of CI-DM and CI-PNM changes was detected (P < 0.001). (4) the change of UES-RP was positively correlated with the change of contractile integral of EB (P < 0.001). CONCLUSIONS: Myotomy of the distal esophagus would attenuate proximal EB contraction and assist UES relaxation in achalasia patients after POEM.