Endosonographic characteristics of the lower esophageal sphincter (LES) in achalasia patients compared to normal individuals and their associations with manometric findings and post-myotomy response

Aims We aimed to compare the characteristics of LES in patients with achalasia and normal individuals using endoscopic ultrasound (EUS). The secondary aim was to evaluate their prognostic value on myotomy orientation during peroral endoscopic myotomy (POEM).

Methods This is a retrospective study of patients with achalasia who underwent POEM during 2019-2022 and a matched control group by gender, height, and BMI. The thickness of the anterior and posterior muscular layers of LES was measured. Eckardt score were recorded up to 24-month post-POEM. Esophageal manometry were performed at baseline and at 1-month.

Results A total of 50 patients were included ([Table 1]). Achalasia group had significantly thicker muscular layers of the LES (p<0.01) with 48% had asymmetrically thickened LES. When look at MP, where myotomy is targeted at, there was no difference in the thickness of posterior MP between the two groups (p=0.27). Among EUS findings, only thickness of muscular layers of anterior MP significantly correlated with pre-POEM manometric findings (p<0.05). All patients underwent POEM. Among patients with asymmetrical LES (n=12), there were no statistically significant differences in clinical response up to 24 months between ipsilateral myotomy on the thickened side versus the contralateral myotomy ([Table 1]).

Table 1  Endosonographic findings between normal and achalasia patients.

Conclusions Once believed to be purely functional disorder, we demonstrated that there were components of anatomical abnormality in achalasia with thicker and more asymmetric LES. Although anterior LES appeared to bear more physiologic significance than posterior side, myotomy can be performed in any orientation. The clinical value of these endosonographic parameters warrant further verification in larger studies.

Publication History

Article published online:
14 April 2023