INTRODUCTION
The peroral endoscopic myotomy (POEM) procedure first described by Inoue in 2010[1] has revolutionized the management of achalasia in many centres around the world as it offers patients a minimally invasive endoscopic solution to their dysphagia caused by achalasia. It appears to be the best treatment for type 3 achalasia as it affords a longer intra-thoracic myotomy to treat the pan-oesophageal dysmotility of type 3 patients[2,3]. However, its use has exploded for achalasia and other associated oesophageal motility disorder in many centres. Alongside its success in alleviating dysphagia, concerns regarding postoperative gastroesophageal reflux disease (GERD) have emerged as a pertinent issue which are not fully resolved. Surgeons have long debated the addition of partial fundoplication to solve this issue in patients having a laparoscopic Heller’s myotomy (LHM) and most have settled on performing a partial fundoplication to improve post-operative GERD symptoms[4]. There are ongoing debates about whether this should be an anterior Dor or a posterior Toupet type fundoplication[5-7]. A Cochrane review performed in 2022 suggested that there may be little to no difference between Dor and Toupet fundoplications with regards to post operative reflux and dysphagia[8]. This review did however find that Nissen (total) fundoplication seemed to increase the risk for post operative dysphagia and should probably be avoided.
In this issue of the World Journal of Gastroenterology, Nabi et al[9] have comprehensively reviewed the topic of the prediction, prevention and management of gastroesophageal reflux after POEM. POEM is a purely endoscopic procedure which is usually performed without any anti-reflux procedure; although some expert centres have performed endoscopic fundoplication in addition to POEM[10-12]. Studies summarised in the review of Nabi et al[9] have shown very high rates of post-operative GERD ranging between 47.1% to 57.8% depending on method of GERD testing. Some of these patients will lack symptoms, but 33.2% to 74.7% are on regular proton pump inhibitor (PPI) medications. Nabi et al[9] argue that the majority of these patients are asymptomatic on PPI and that the GERD is found on testing rather than patients being symptomatic and that severe complicated oesophagitis is uncommon after POEM. However, long term PPI therapy is not without risk with the potential for significant complications including pneumonia, Clostridium difficile infection, electrolyte disturbances, osteoporosis and kidney disease[13,14]. Although the evidence base for many of these complications is by association rather than direct causality, it is imperative that patients are on these medications at the lowest dose possible and for appropriate indications. When the pros and cons of various achalasia treatments are discussed with patients, the need for long term PPIs following POEM should be discussed and some patients may prefer to have a LHM with an anti-reflux procedure.
Risk factors for post POEM GERD highlighted in review of Nabi et al[9] are a higher body mass index > 35 kg/m2, the presence of hiatal hernia, a low integrated relaxation pressure post-POEM, pre-POEM lower esophageal sphincter (LES) pressures below 45 mmHg, low post-POEM LES pressure, and female gender. The achalasia community should perhaps consider whether these patients might be better suited to a laparoscopic Heller’s cardiomyotomy and partial fundoplication rather than a POEM. Technical factors related to the exact POEM technique that are predisposing to post-POEM GERD include the following: Long esophageal myotomy, posterior myotomy, full thickness myotomy and excess myotomy (> 4 cm) on the gastric side. The review by Nabi et al[9] discusses the lack of evidence relating to the precise myotomy lengths on both the oesophageal and gastric side and importantly highlights the strong need for better quality studies in this area.
The dilemma facing both patients and healthcare providers lies in striking a delicate balance between effectively treating achalasia while minimizing the risk of exacerbating or inducing GERD. Achieving this balance requires a multifaceted approach, beginning with thorough preoperative evaluation and patient selection. Identifying individuals with a predisposition to reflux or those with concomitant esophageal pathology is crucial in managing expectations and implementing appropriate preventative measures. A large study from the United States has shown that the use of POEM has increased rapidly since 2010 (1.1% in 2010 compared with 18.9% in 2017)[15]. When compared with LHM adverse events were rare and did not differ between procedures. Compared with LHM, POEM was associated with more subsequent diagnostic testing and reinterventions. This is almost certainly in part to issues around reflux requiring additional endoscopies and pH testing. It remains uncertain what percentage of patients with a POEM end up needing a subsequent surgical or endoscopic anti-reflux procedure. Again, patients need to be adequately counselled about this risk.
As POEM is a relatively novel procedure compared with LHM, long term data is sparse but there are an increasing number of studies comparing the longer term outcomes between the two. Costantini et al[16] reported on their outcomes out to 5 years and showed that POEM and LHM performed similarly well (> 90%) with regards to clinical success. However, patients who had undergone POEM had higher rates of % total exposure to acid time and DeMeester scores on 24 h pH manometry, along with higher rates of endoscopically confirmed oesophagitis. Podboy et al[17] performed a retrospective cohort study that showed equipoise in success rates for both POEM and LHM based on post procedure Eckardt scores. Both groups self-reported recurrent GERD symptoms at a similar rate (44.9% POEM vs 46.5% LHM) at a mean follow up of 3.94 years.
CONCLUSION
In conclusion, GERD following POEM for achalasia underscores the intricate balance between therapeutic efficacy and potential adverse effects. While post-POEM GERD remains a high and potentially significant complication, advances in procedural techniques and postoperative management strategies offer promise in mitigating its impact on patient outcomes. By embracing a comprehensive approach that prioritizes individualized care, gastroenterologists and surgeons can optimize the long-term success of achalasia treatments while minimizing the burden of reflux disease for patients. Certain patients may be better served by a LHM and fundoplication and it is important that gastroenterologists and surgeons provide comprehensive risks and benefits of each achalasia treatment option so that patients can decide what treatment is best for them. This article by Nabi et al[9] provides a comprehensive review of the current status of this issue to allow these discussions to occur.
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Provenance and peer review: Invited article; Externally peer reviewed.
Peer-review model: Single blind
Specialty type: Gastroenterology and hepatology
Country of origin: United Kingdom
Peer-review report’s classification
Scientific Quality: Grade B
Novelty: Grade B
Creativity or Innovation: Grade B
Scientific Significance: Grade B
P-Reviewer: Bi YW, China S-Editor: Wang JJ L-Editor: A P-Editor: Yu HG