Should we focus on the fight against achalasia or equivocal results of reflux after peroral endoscopic myotomy?

Kumbhari et al. [1] recently published an interesting retrospective multicenter cohort study on 282 patients with achalasia who were treated by peroral endoscopic myotomy (POEM). The study, which was conducted in six Western and a single Asian center, surprisingly reported substantial increased incidence of gastroesophageal reflux (GER) after POEM based on high DeMeester score postoperatively (163 /282 [57.8 %]; mainly “silent” GER 95 /158 [60.1 %] not taking proton pump inhibitors), while on upper endoscopy after POEM, a total of 23.2 % showed erosive esophagitis, which was mainly mild (Los Angeles grade A or B 41 /54 [75.9 %]); severe esophagitis (grade C or D) occurred in only 13 /282 patients (4.6 %) (Table 2 in the paper) [1]. These results are in contrast not only to large Japanese studies [2], which have reported less than 10 % mild esophagitis, but also to previous international data [3].

However, asymptomatic or “silent GER,” a term introduced for reflux-associated asthma in children and defined as a “reflux episode with no discrete symptoms,” is known to be common even in healthy populations [4], and its use in the Kumbhari study overestimated and boosted GER after POEM up to 60 %. This makes the results of this study confusing and incomparable to other studies, as most studies regarding GER only focus on clinical symptomatic GER. This could be one reason for the great differences between Western and Eastern studies, as Asian studies have focused on symptomatic rather than silent or asymptomatic GER.

The authors also discuss the terrifying scenario of post-POEM GER leading to Barrett’s esophagus and even to Barrett’s-related adenocarcinoma. However, the issue of esophageal cancer risk in achalasia [5], whether squamous cell carcinoma, esophageal or Barrett’s-related adenocarcinoma, is not new, presents considerable variation, and is not absolutely related to POEM.

The results of this study are, in many aspects, questionable and doubtful, and in no sense definite. The data presented here, from 2009 to 2014, referred to the early stage of POEM, when the technique was only just starting to spread beyond Japan and international experience was limited; even specialized centers were not familiar with the technique. Increased experience and quality in high-volume Asian centers might be another possible explanation for the differences in GER after POEM between West and East.

The Kumbhari study included mainly anterior and full-thickness myotomy cases. More recently, posterior POEM and selective circular myotomy have become the techniques preferred by pioneering centers [2]. What about post-POEM GER in posterior POEM with selective circular myotomy?

POEM has demonstrated resolution of symptoms in the long term, and was practically the only realistic therapeutic option available in end-stage sigmoid type achalasia and megaesophagus, after failure of previous repeated balloon dilations or surgery, in octogenarians, and in patients with absolute contraindications to surgery [2]. In my opinion, it is too early to make safe and final conclusions regarding POEM.

However, one thing is certain: POEM opens a new era in modern endoscopic treatment for achalasia, giving realistic therapeutic resolution in cases where all other treatments have failed or are contraindicated. Further prospective, multicenter studies, including from the pioneering Asian centers, are necessary.

• References

• 1 Kumbhari V, Familiari P, Bjerregaard NC. et al. Gastroesophageal reflux after peroral endoscopic myotomy: a multicenter case–control study. Endoscopy 2017; 49: 634-642
• 2 Bechara R, Onimaru M, Ikeda H. et al. Per-oral endoscopic myotomy, 1000 cases later: pearls, pitfalls, and practical considerations. Gastrointest Endosc 2016; 84: 330-338
• 3 Stavropoulos SN, Modayil RJ, Friedel D. et al. The International Per Oral Endoscopic Myotomy Survey (IPOEMS): a snapshot of the global POEM experience. Surg Endosc 2013; 27: 3322-3338
• 4 Lei WY, Yu HC, Wen SH. et al. Predictive factors of silent reflux in subjects with erosive esophagitis. Dig Liver Dis 2015; 47: 24-29
• 5 Sandler RS, Nyren O, Ekbom A. et al. The risk of esophageal cancer in patients with achalasia. A population-based study. JAMA 1995; 274: 1359-1362