Ling classification describes endoscopic progressive process of achalasia and successful peroral endoscopy myotomy prevents endoscopic progression of achalasia

Table 1 Demographic characteristics of patients presenting with achalasia n (%)

Characteristic	Value
Sex, female/male (n)	197/162
Age (yr), mean (range)	42.1 (12-75)
Duration of symptoms (mo), median (range)	36 (2-360)
Lower esophageal sphincter pressure (mmHg), mean (range)	33.0 (0.7-72.4)
Ling classification
I	119 (33.1)
IIa	106 (29.5)
IIb	60 (16.7)
IIc	60 (16.7)
III	14 (3.9)

Table 2 Comparison of symptom duration, lower esophageal sphincter pressure, and dysphagia score among Ling classifications

Ling type	I	IIa	IIb	IIc	III	P value
n	119	106	60	60	14
Onset age (yr), mean	35.3	38.9	36.1	36.4	32.9	> 0.05
Age at time of diagnosis (yr), mean	38.5	42.8	43.8	46.4	45.4	< 0.05
Sex (female/male)	65/54	60/46	32/28	35/25	5/9	> 0.05
Duration (mo), median	24	36	60	72	120	< 0.05
LESP (mmHg), mean	35	34.7	32.8	28.9	16.9	< 0.05

LESP: Lower esophageal sphincter pressure.

Table 3 Demographics and treatment outcomes of the 21 patients with a post-peroral endoscopic myotomy follow-up for > 2 years n (%)

Characteristic	Value
Sex, female/male (n)	9/12
Age (yr), mean (range)	43.8 (16-62)
Duration of symptoms (mo), median (range)	36 (6-120)
Endoscopic follow-up (mo), mean (range)	37.8 (24-51)
Manometry follow-up rate	19 (90.5)
Lower esophageal sphincter pressure (mmHg), mean (range)
Pre-treatment	34.6 (15.3-59.4)
Post-treatment	15.0 (2.1-21.6)
Ling classification
I	8 (38.1)
IIa	7 (33.3)
IIb	5 (23.8)
IIc	0 (0)
III	1 (4.8)
Treatment success rate (Eckardt score ≤ 3)	21 (100)