Background:
Peroral endoscopic myotomy (POEM) is standard treatment for achalasia. Gastroesophageal reflux disease (GERD) after POEM has been a limiting factor with this procedure. Preservation of the sling fiber during POEM was reported to reduce post-POEM GERD in Japan, but there are no reports of this technique in a western population.

Aims:
The aim is to investigate the association of sling-fiber preservation during POEM and post-POEM GERD symptoms at our institution, which is a large therapeutic endoscopy referral center in Canada.

Methods:
This is a retrospective, single-center study of patients who underwent POEM from October 2017 to January 2023 at our center. The initial cohort of patients were treated by conventional POEM until June 2021, after which a second cohort underwent POEM with sling-fiber preservation, as the techniques advanced. The primary outcome was the rate of positive GERD symptoms after POEM. The secondary outcomes were procedure time, gastric myotomy length, clinical success rate (Eckard score of less than 3), adverse events rate, use of PPI at follow-up. Multivariate regression was performed to identify factors that reduce post-POEM GERD symptoms. The model included the following factors, which were reported as risk factors for post-POEM GERD: age, gender, IRP, barium type, degree of esophageal dilation, and gastric myotomy length.

Results:
148 POEM cases (52.5±15.6 y/o, female:61(43%)) were included in this study. There was no significant difference in patient characteristics between the groups. The mean procedure time (108.6±34.5 vs 109.1±45.7 min, P=0.93) and rate of adverse events (21% vs 14%, P=0.36) were similar between the traditional and modified groups. In the sling fiber preservation group, gastric myotomy length was significantly longer (2.2±0.7 vs 1.6±0.8 cm, P<0.05) yet the GERD symptom rate at follow-up was significantly lower (22% vs 41%, P<0.05), although PPI use was similar (57% vs 50%, P=0.47). The clinical success rate was similar between groups (88% vs 84%, P=0.6). Regression analysis indicated that, after adjusting for other factors, sling-fiber preservation during POEM had an odds ratio of 0.24 (95% CI: 0.07-0.85, P=0.027) for post-POEM GERD symptoms.

Conclusions:
Sling-fiber preservation during POEM is safe and effectively reduces post-POEM GERD symptoms, despite a longer gastric myotomy length. It stands as a significant independent factor in reducing post-POEM GERD symptoms. Hence, sling-fiber preservation may be a beneficial solution for reducing post-POEM GERD symptoms in Western populations.

Table of clinical outcomes for conventional POEM and Sling fiber preservation POEM.

Diagram of sling fibers and clasp fibers. The red line represents the myotomy line in sling-fiber preservation POEM, while the blue line represents the myotomy line of conventional POEM (A). Endoscopic image of a submucosal tunnel showcasing both sling fibers and clasp fibers (B).

Yusuke Fujiyoshi

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SLING FIBER PRESERVATION DURING POEM REDUCES POST-POEM GERD SYMPTOMS

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