Study on the Relationship Between Different Pathological Features of Achalasia and Prognosis of Per-oral Endoscopic Myotomy

Achalasia is the most common motility disorder of esophagus, characterized by disorders of the lower esophageal sphincter (LES). Normal peristalsis of the esophagus is eliminated and replaced by synchronous or ineffective contraction. Based on high-resolution manometry (HRM), the participants with achalasia were categorized into 3 subtypes, type I: achalasia with minimum esophageal pressurization, type II: achalasia with esophageal compression and type III: achalasia with spasm.

Previous studies have found that the pathological features of the esophageal muscular layers in participants with achalasia are degeneration of nerve plexus, reduction of interstitial cells of Cajal (ICCs) and infiltration of different inflammatory cells. Different subtypes of achalasia have different clinical characteristics and esophageal motility. Studies have found that ganglion cells in type I participants are significantly reduced compared with type II participants, but the pattern is similar, which may indicate that type I achalasia represents the progression of type II achalasia. In addition, Achalasia is related to viral infection and autoimmune disease. Studies have shown that pathological biopsies of muscle in participants with achalasia show significantly increased rates of lymphocytes in tissues, as well as mast cells.

Now, per-oral endoscopic myotomy (POEM) is a main therapy for participants with achalasia. Most studies have focused on the relationship between pathological features and motility characteristics of achalasia, but there are few studies on the relationship between pathological features and therapeutic effect of POEM.

This study will prospectively collect data of participants undergoing POEM for achalasia in Beijing Friendship Hospital, including demographic data, drug and surgical treatment data during hospitalization. All participants are required to obtain esophageal muscle biopsy for pathological examination during POEM. The participants will be followed up until 12 months for improvement in clinical symptoms and gastroesophageal reflux after POEM.