Abstract
Abnormalities in the upper esophageal sphincter (UES) in patients with achalasia and the impact of peroral endoscopic myotomy (POEM) on the UES and esophageal body remain uncertain. To outline the prevalence and nature of UES abnormalities across different achalasia subtypes, as well as evaluate POEM's therapeutic efficacy on UES and esophageal body. A retrospective study of patients diagnosed with achalasia between January 2019 and December 2023 was conducted. POEM was performed on all patients, and preoperative and 6-month postoperative high-resolution esophageal manometry (HREM) data were obtained, along with the Eckardt symptom scores. A total of 64 patients (34 females, 30 males) who underwent POEM for achalasia (type I: 18, type II: 38, type III: 8) during the study period were included. Among the 64 patients, 42 (65.6%) exhibited abnormalities in the UES, as observed on HREM. The majority of those exhibiting abnormalities demonstrated impaired relaxation of the UES (46.9%), followed by a combination of hypertensive basal UES pressure (UESP) and impaired UES relaxation (12.5%). The dysphagia score and Eckardt score before POEM were significantly greater in the UES abnormality group than in the normal UES group (2.3 ± 0.7 vs. 1.9 ± 0.7, p = 0.040 and 6.2 ± 1.8 vs. 5.0 ± 1.6, p = 0.008, respectively). UESP and UES relaxation pressure (UESRP) decreased significantly following POEM across all types of achalasia (p < 0.05). All type I patients continued to exhibit no contractility after undergoing POEM. Pan-esophageal pressurization and spastic contractions were absent in patients with type II and type III achalasia following POEM. The high prevalence of UES abnormalities among patients with achalasia may serve as a compensatory mechanism. Patients with type II and III showed partial recovery of peristalsis following POEM.