PD	Pneumatic dilation
p	p-value
LES	Lower esophageal sphincter
EGJ	Esophagogastric junction
EGDS	Esophagogastroduodenoscopy
POEM	Peroral endoscopic myotomy
ESGE	European Society of Gastrointestinal Endoscopy
M	Mean
SD	Standard deviation
Min.	Minimum
Max.	Maximum
N	Sample size
M	Male
F	Female
y	Year
Regurg.	Regurgitation
F	F-ratio
df	Degrees of freedom
ANOVA	Analysis of Variance
t	t-test with Bonferroni correction
class.	Classification