Published online May 14, 2017. doi: 10.3748/wjg.v23.i18.3309
Peer-review started: January 5, 2017
First decision: January 19, 2017
Revised: February 1, 2017
Accepted: March 30, 2017
Article in press: March 30, 2017
Published online: May 14, 2017
To verify the hypothesis that the Ling classification describes the endoscopic progressive process of achalasia and determine the ability of successful peroral endoscopic myotomy (POEM) to prevent endoscopic progression of achalasia.
We retrospectively reviewed the endoscopic findings, symptom duration, and manometric data in patients with achalasia. A total of 359 patients (197 women, 162 men) with a mean age of 42.1 years (range, 12-75 years) were evaluated. Symptom duration ranged from 2 to 360 mo, with a median of 36 mo. Patients were classified with Ling type I (n = 119), IIa (n = 106), IIb (n = 60), IIc (n = 60), or III (n = 14), according to the Ling classification. Of the 359 patients, 349 underwent POEM, among whom 21 had an endoscopic follow-up for more than 2 years. Pre-treatment and post-treatment Ling classifications of these 21 patients were compared.
Symptom duration increased significantly with increasing Ling classification (from I to III) (P < 0.05), whereas lower esophageal sphincter pressure decreased with increasing Ling type (from I to III) (P < 0.05). There was no difference in sex ratio or onset age among the Ling types, although the age at time of diagnosis was higher in Ling types IIc and III than in Ling types I, IIa, and IIb. Of the 21 patients, 19 underwent high-resolution manometry both before and after treatment. The mean preoperative and postoperative lower esophageal sphincter pressure were 34.6 mmHg (range, 15.3-59.4 mmHg) and 15.0 mmHg (range, 2.1-21.6 mmHg), respectively, indicating a statistically significant decrease after POEM. All of the 21 patients were treated successfully by POEM (postoperative Eckardt score ≤ 3) and still had the same Ling type during a mean follow-up period of 37.8 mo (range, 24-51 mo).
The Ling classification represents the endoscopic progressive process of achalasia and may be able to serve as an endoscopic assessment criterion for achalasia. Successful POEM (Eckardt score ≤ 3) seems to have the ability to prevent endoscopic evolvement of achalasia. However, studies with larger populations are warranted to confirm our findings.
Core tip: Achalasia is a progressive disease, as verified by manometric and radiographic findings. Thus, we speculated that this progressive process could be visualized by endoscopy. We have proposed the Ling classification for achalasia on the basis of the endoscopic morphological severity of the esophagus. This study supports the hypothesis that the Ling classification portrays the progressive process of achalasia. Preliminary evidence suggests that successful peroral endoscopic myotomy (POEM) has the ability to prevent endoscopic progression of achalasia. Moreover, this study suggests that the Ling classification may serve as a criterion for endoscopic assessment of achalasia and will be useful for long-term endoscopic follow-up of post-POEM achalasia.