Comparison of the Outcomes of Peroral Endoscopic Myotomy for Achalasia According to Manometric Subtype

Background/Aims: We evaluated whether manometric subtype is associated with treatment outcome in patients with achalasia treated by peroral endoscopic myotomy (POEM). Methods: High-resolution manometry data and Eckardt scores were collected from 83 cases at two tertiary referral centers where POEM is performed. Manometric tracings were classified according to the three Chicago subtypes. Results: Among the 83 cases, 48 type I, 24 type II, and 11 type III achalasia cases were identified. No difference was found in pre-POEM Eckardt score, basal lower esophageal sphincter (LES) pressure, or integrated relaxation pressure (IRP) among the type I, type II, and type III groups. All three patient groups showed a significant improvement in post POEM Eckardt score (6.1 +/- 2.1 to 1.5 +/- 1.5, p=0.001; 6.8 +/- 2.2 to 1.2 +/- 0.9, p=0.001; 6.6 +/- 2.0 to 1.6 +/- 1.4, p=0.011), LES pressure (26.1 +/- 13.8 to 15.4 +/- 6.8, p=0.018; 32.3 +/- 19.0 to 19.2 +/- 10.4, p=0.003; 36.8 +/- 19.2 to 17.5 +/- 9.7, p=0.041), and 4s IRP (21.5 +/- 11.7 to 12.0 +/- 8.7, p=0.007; 24.5 +/- 14.8 to 12.0 +/- 7.6, p=0.002; 24.0 +/- 15.7 to 11.8 +/- 7.1, p=0.019) at a median follow-up of 16 months. Conclusions: POEM resulted in a good clinical outcome for all manometric subtypes.