Myotomy with muscularis dissection improves clinical outcome of peroral endoscopic myotomy

Aims Peroral endoscopic myotomy (POEM) is the first choice of treatment for esophageal achalasia and has been widely performed worldwide. However, there are a small number of cases in which treatment is inadequately effective or failure to achieve clinical improvement. In addition, morphological abnormalities such as blown out myotomy (BOM), a localized increase in lumen diameter in the distal esophagus, may occur after POEM, which may reduce the efficacy of treatment. We hypothesized that inadequate myotomy is the cause of treatment failure in POEM, so we devised a method of dissecting between the circular and longitudinal muscles and then performing myotomy to obtain adequate LES relaxation. A retrospective study was conducted to evaluate the efficacy of myotomy with muscularis dissection in POEM.

Methods Patients who underwent initial POEM for esophageal achalasia and related diseases between November 2019 and March 2024 were included in the study. Patient background and outcomes were analyzed retrospectively for two groups: a conventional myotomy group (MD group) and a myotomy with muscularis dissection group (MMD group). The primary endpoint was improvement in clinical symptoms using the Eckardt score, and secondary endpoints were operation time, perioperative adverse event rate, and incidence of gastroesophageal reflux disease after POEM. All patients underwent an anterior or posterior myotomy, and the myotomy was confirmed to have reached the gastric side using the double scope method.

Results Forty-eight patients were in the CM group, median age 62.5 years, 25 males (52%), 40 patients with esophageal achalasia, 5 with EGJOO, 3 with DES, and median preoperative Eckard score 7 (2-10). DDM group consisted of 15 patients, median age 57 years, 7 males (47%), 13 with esophageal achalasia, 2 with EGJOO, and a median preoperative Eckard score of 5 (1-10). There were no differences in pretreatment patient factors between the two groups. The Eckardt score after POEM was 1 (0-3) in the CM group and 0 (0-2) in the MMD group, with Eckardt score≤3 achieved in both groups, but significantly lower in the MMD group (p=0.03). There was no difference in operation time (91.5 min vs 97 min, p=0.33), but the time required for myotomy per cm was significantly longer in the MMD group (2.5 min vs. 3.9 min, p<0.01). Adverse event rates were similar (12.5% vs. 6.7%, p=1), and there was no difference in the incidence of≥Grade B GERD after POEM (35.7% vs. 40%, p=0.83), and no esophageal diverticulum including BOM occurred in the MMD group [1] [2].

Conclusions Myotomy with muscularis dissection in POEM was associated with symptomatic improvement compared to the conventional method. The incidence of treatment failure and BOM after POEM may be due to incomplete myotomy or improper direction of myotomy, adequate myotomy should be performed in the appropriate direction.

Publikationsverlauf

Artikel online veröffentlicht:
27. März 2025

• References

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• 2 Triggs JR, Krause AJ, Carlson DA, Donnan EN, Campagna RAJ, Jain AS, Kahrilas PJ, Hungness ES, Pandolfino JE.. Blown-out myotomy: an adverse event of laparoscopic Heller myotomy and peroral endoscopic myotomy for achalasia. Gastrointest Endosc 2021; 93 (04): 861-868.e1