A Retrospective Study of Peroral Endoscopic Full-Thickness Myotomy in Patients with Severe Achalasia

Effectiveness and safety of full-thickness versus circular muscle myotomy in peroral endoscopic myotomy: a retrospective single-center analysis of 152 patients

BACKGROUND

Achalasia is a primary esophageal motility disorder, which shows impaired relaxation of the lower esophageal sphincter (LES) and the absence of peristalsis, leading to dysphagia, weight loss, and chest pain. In recent years, peroral endoscopic myotomy (POEM) has become a popular method for treating achalasia. However, the effectiveness and safety of full-thickness myotomy (FTM) versus circular muscle myotomy (CMM) in POEM require further investigation.

METHODS

This retrospective single-center analysis studied 152 patients who underwent POEM surgery at the General Hospital of the Western Theater Command from May 2014 to May 2023. Patients were divided into two groups based on the depth of myotomy: the FTM group and the CMM group. Parameters such as surgical success rate, procedure time, and myotomy length were evaluated, and treatment efficacy was assessed based on the Eckardt score. Postoperative complications and efficacy were also monitored.

RESULTS

Technical success was achieved in both groups, with shorter procedure times in the FTM group (P < 0.05). There were no significant differences in postoperative Eckardt scores and symptom improvement between the FTM and CMM groups. The incidence of adverse events was similar in both groups. The incidence of gastroesophageal reflux disease (GERD) seemed to be higher in the FTM group, although this difference was not statistically significant (P = 0.051).

CONCLUSION

For patients with achalasia, there were no significant differences in short-to-medium-term treatment efficacy and safety between FTM and CMM in POEM. Although FTM significantly reduced procedure time, it may lead to a higher incidence of GERD. More cases are needed in the future to explore the more appropriate myotomy for different achalasia subtypes.

A long-term follow-up study of gastric peroral endoscopic myotomy (G-POEM) in a large cohort of patients with postsurgical gastroparesis

INTRODUCTION

Postoperative gastroparesis occurs after surgeries which affect the upper digestive tract. Gastric peroral endoscopic myotomy (G-POEM) is a treatment for postoperative gastroparesis. The present study boasts the long-term efficacy and safety of G-POEM in a large cohort of patients.

PATIENTS AND METHODS

Gastroparesis Cardinal Symptom Index (GCSI) and Gastroesophageal Reflux Disease Questionnaire (GERDQ) were utilized for the assessment of postsurgical gastroparesis symptoms. Gastroscope was used to observe the anastomotic site. Three-dimensional ultrasound was used to measure the morphological structure of the gastric antrum and pylorus tube. Gastric emptying time was calculated by analyzing the volume change of gastric antrum.

RESULTS

Significant clinical effectiveness of G-POEM was observed. The GCSI score, including each subscale score, showed significant decrease after G-POEM. Before G-POEM, there was a negative correlation between GCSI score and the inner diameter of pylorus, as well as a positive correlation with the length of pyloric tube. The similar results were found in the scores of nausea/vomiting and postprandial fullness/early satiety subscales. No correlation was observed between GCSI score and the emptying time, nor between the emptying time and the parameters of antrum morphology. After G-POEM, no correlation was found between GCSI (including subscales) score, the emptying time, and the parameters of antrum morphology. Patients who exhibited as clinical non-responders often accompanied with GERD symptoms. After G-POEM, the score of GERDQ decreased significantly. Either before or after G-POEM, no correlation was noticed between GERDQ scores, the emptying time and the parameters of antrum morphology.

CONCLUSION

The technique of G-POEM was demonstrated as a minimally invasive approach with the long-term efficacy and safety in therapying postoperative gastroparesis.

Advances in Third Space Endoscopy

This article offers a detailed overview of recent advancements in third space endoscopy (TSE), highlighting key procedures and their clinical applications and outcomes. Clinical TSE started as a treatment for achalasia and was named peroral endoscopic myotomy (POEM). Outcome data and comparative data of POEM with other treatments were detailed and discussed. This article also explores the indications and outcomes of other TSE procedures, such as G-POEM, Z-POEM, D-POEM, per-rectal endoscopic myotomy, and STER/POET. This article serves as a valuable resource for endoscopists looking to enhance their understanding and stay updated on these advanced TSE procedures.

Incidence and risk factors of reflux esophagitis after peroral endoscopic myotomy

BACKGROUND

Peroral endoscopic myotomy (POEM) is an effective and safe treatment for achalasia, but often leads to posttreatment gastroesophageal reflux disease. The aim of this study was to examine the incidence and severity of reflux esophagitis after POEM and to identify associated predictive factors.

METHODS

Patients who underwent POEM between August 2011 and December 2022 were included. Multivariate logistic regression was used to assess predictive factors for reflux esophagitis after POEM.

KEY RESULTS

In total, 252 patients were included; of which, 46% were female and age ranged between 18 and 87 years. Reflux esophagitis within 1 year after POEM was observed in 131 patients (52%), which was severe in 29 patients (LA grade C/D, 12%). Length of full-thickness myotomy (cm; OR 1.11, 95% CI 1.02-1.21), Eckardt scores before POEM (OR 0.84, 95% CI 0.74-0.96), previous pneumatic dilation (OR 0.51, 95% CI 0.29-0.91), and previous laparoscopic Heller myotomy (LHM; OR 0.44, 95% CI 0.23-0.86) were associated with reflux esophagitis after POEM. Alcohol use (none vs > 7 units per week; OR 3.51, 95% CI 1.35-9.11) and overweight (BMI ≥25 kg/m2; OR 2.67, 95% CI 1.17-6.09) were positive predictive factors and previous LHM (OR 0.13, 95% CI 0.02-0.95) was a negative predictive factor for severe reflux esophagitis after POEM (LA grade C/D).

CONCLUSION

About half of the patients develop reflux esophagitis after POEM and 12% is graded as severe. Recognizing predictive factors of reflux esophagitis after POEM treatment leads to better patient selection before POEM and provides an opportunity to take preventive measures or start preemptive treatment.

Comparing clinical outcomes of peroral endoscopic myotomy for achalasia between Eastern and Western countries: a systematic review and meta-analysis

Peroral endoscopic myotomy (POEM) has revolutionized the therapeutic strategy for achalasia with promising results. We conducted this meta-analysis to compare clinical outcomes between Eastern and Western countries. A comprehensive literature search was conducted in PubMed, EMBASE, Web of Science and Cochrane Library databases to query for studies that assessed the efficacy of POEM for achalasia. All articles published from inception to December 31, 2021 were included. The primary outcome was the pooled clinical success rate. The secondary outcomes included the pooled technical success rate, incidence of adverse events, procedure time and hospital stay. Eighteen Eastern studies involving 5962 patients and 11 Western studies involving 1651 patients were included. The pooled clinical success rate and technical success rate for POEM was equal in the Eastern studies compared to Western studies. The pooled incidence of procedure adverse events for POEM was a little lower in the Eastern studies compared to Western studies (6.6% vs. 8.7%). Similarly, the incidence of reflux-related adverse events was lower in Eastern studies than that in Western studies. The pooled procedure time of POEM was shorter in Eastern studies compared to Western studies (61 minutes vs. 80 minutes), while the length of hospital stay was longer in Eastern studies compared to Western studies (5.8 days vs. 2.4 days). Overall, Eastern countries have the similar POEM outcomes compared to Western countries. However, Eastern countries still need to do more to reduce the length of hospital stay.

Third-space endoscopy: the final frontier

Over the years, our growing experience with endoscopic submucosal dissection along with technological advances has solidified our comfort and knowledge on working in the submucosa, also referred to as the "third space." Per-oral endoscopic myotomy (POEM) was the first prototype third-space endoscopy (TSE) procedure, demonstrating the feasibility and clinical utility of endoscopic esophagogastric myotomy via submucosal tunneling. The launch of POEM accelerated the evolution of TSE from a vanguard concept to an expanding field with a wide range of clinical applications. In this review, we discuss the status and future directions of multiple TSE interventions.

Is peroral endoscopic myotomy the new gold standard for achalasia therapy?

Our review focuses on critical analysis of the literature to determine whether peroral endoscopic myotomy (POEM) is poised to replace laparoscopic Heller myotomy (LHM) as the new "gold standard" for achalasia therapy. POEM matches or exceeds the efficacy of LHM. The difference in objective gastroesophageal reflux disease (GERD) between POEM and LHM is modest at best and dissipates with time. Post-POEM GERD can be easily managed medically in most patients without long-term GERD sequelae or the need for surgical fundoplication. Emerging POEM technique modifications can further decrease GERD. Endoscopic antireflux procedures such as transoral incisionless fundoplication (TIF) or POEM + F (POEM + fundoplication) can be used in the rare cases of medication-refractory GERD, but their long-term efficacy remains in question. In this comprehensive review, we summarize the current status of POEM with emphasis on GERD evaluation, prevention, treatment, and comparative data vs. LHM. Based on this analysis, it appears that POEM is indeed the new gold standard in the therapy of achalasia.

Peroral endoscopic myotomy vs laparoscopic myotomy and partial fundoplication for esophageal achalasia: A single-center randomized controlled trial

BACKGROUND

Achalasia is a rare benign esophageal motor disorder characterized by incomplete relaxation of the lower esophageal sphincter (LES). The treatment of achalasia is not curative, but rather is aimed at reducing LES pressure. In patients who have failed noninvasive therapy, surgery should be considered. Myotomy with partial fundoplication has been considered the first-line treatment for non-advanced achalasia. Recently, peroral endoscopic myotomy (POEM), a technique that employs the principles of submucosal endoscopy to perform the equivalent of a surgical myotomy, has emerged as a promising minimally invasive technique for the management of this condition.

AIM

To compare POEM and laparoscopic myotomy and partial fundoplication (LM-PF) regarding their efficacy and outcomes for the treatment of achalasia.

METHODS

Forty treatment-naive adult patients who had been diagnosed with achalasia based on clinical and manometric criteria (dysphagia score ≥ II and Eckardt score > 3) were randomized to undergo either LM-PF or POEM. The outcome measures were anesthesia time, procedure time, symptom improvement, reflux esophagitis (as determined with the Gastroesophageal Reflux Disease Questionnaire), barium column height at 1 and 5 min (on a barium esophagogram), pressure at the LES, the occurrence of adverse events (AEs), length of stay (LOS), and quality of life (QoL).

RESULTS

There were no statistically significant differences between the LM-PF and POEM groups regarding symptom improvement at 1, 6, and 12 mo of follow-up (P = 0.192, P = 0.242, and P = 0.242, respectively). However, the rates of reflux esophagitis at 1, 6, and 12 mo of follow-up were significantly higher in the POEM group (P = 0.014, P < 0.001, and P = 0.002, respectively). There were also no statistical differences regarding the manometry values, the occurrence of AEs, or LOS. Anesthesia time and procedure time were significantly shorter in the POEM group than in the LM-PF group (185.00 ± 56.89 and 95.70 ± 30.47 min vs 296.75 ± 56.13 and 218.75 ± 50.88 min, respectively; P = 0.001 for both). In the POEM group, there were improvements in all domains of the QoL questionnaire, whereas there were improvements in only three domains in the LM-PF group.

CONCLUSION

POEM and LM-PF appear to be equally effective in controlling the symptoms of achalasia, shortening LOS, and minimizing AEs. Nevertheless, POEM has the advantage of improving all domains of QoL, and shortening anesthesia and procedure times but with a significantly higher rate of gastroesophageal reflux.

Evolution and evidence-based adaptations in techniques for peroral endoscopic myotomy for achalasia

Achalasia is an esophageal motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation and failed peristalsis. Common clinical manifestations include dysphagia to solid and liquid foods, chest pain, regurgitation, and weight loss, resulting in significant morbidity and healthcare burden. Historically, surgical Heller myotomy and pneumatic dilation were the first-line therapeutic options for achalasia. This convention was shaken in 2009 when Inoue and colleagues introduced an endoscopic approach to dissect the muscle fibers of the LES, known as peroral endoscopic myotomy (POEM). Since incorporation of POEM into standard practice, the overall myotomy technique has remained unchanged; however, adaptations in the thickness and length of myotomy have evolved. Full-thickness myotomy is recognized to have similar clinical success and faster procedure times compared with selective circular muscle myotomy. Although myotomy length for type 1 and type 2 achalasia has classically been >6 cm, recent studies demonstrated similar outcomes with reduction of myotomy length to <3 cm. Length of myotomy for type 3 achalasia has been tailored to treat the entire length of spastic muscle segment, and the modality to gauge the optimal thickness and length of myotomy in this group has yet to be established. In addition to changes in POEM technique, the postoperative management of POEM has also changed, favoring reduced postprocedure imaging, antibiotic use, and hospitalizations.

POEM, GPOEM, and ZPOEM

Our tripartite narrative review discusses Peroral Endoscopic Myotomy (POEM), gastric POEM (GPOEM) and POEM for Zenker's diverticula (ZPOEM). POEM is the prototypical procedure that launched the novel "3rd space endoscopy" field of advanced endoscopy. It revolutionized achalasia therapy by offering a much less invasive version of the prior gold standard, the laparoscopic Heller myotomy (HM). We review in detail indications, outcomes, technique variations and comparative data between POEM and HM particularly with regard to the hotly debated issue of GERD. We then proceed to discuss two less illustrious but nevertheless important offshoots of the iconic POEM procedure: GPOEM for gastroparesis and ZPOEM for the treatment of hypopharyngeal diverticula. For GPOEM, we discuss the rationale of pylorus-directed therapies, briefly touch on GPOEM technique variations and then focus on the importance of proper patient selection and emerging data in this area. On the third and final part of our review, we discuss ZPOEM and expound on technique variations including our "ultra-short tunnel technique". Our review emphasizes that, despite the superiority of endoscopy over surgery for the treatment of hypopharyngeal diverticula, there is no clear evidence yet of the superiority of the newfangled ZPOEM technique compared to the conventional endoscopic myotomy technique practiced for over two decades prior to the advent of ZPOEM.

An Updated Meta-analysis: Similar Clinical Efficacy of Anterior and Posterior Approaches in Peroral Endoscopic Myotomy (POEM) for Achalasia

Introduction

Currently, there are few studies on the efficacy of peroral endoscopic myotomy (POEM) in the anterior or posterior approach; however, limited studies have shown contradictory findings. Thus, the goal was to obtain more quantitative and objective outcomes and further compare the clinical efficacy of these two approaches in this meta-analysis.

Methods

A comprehensive search of PubMed, Embase, Cochrane Library, and Web of Science was conducted to find studies relevant to POEM. The retrieval time was from database inception to September 2021. Studies reporting the effects of POEM according to the anterior or posterior approach were included. STATA 16.0 was used to perform statistical analysis, mainly comparing the quantitative objective indicators (lower esophageal sphincter (LES) pressure and Eckardt scores, etc.) in anterior and posterior approaches by meta-analysis.

Result

A total of 19 studies with 1261 patients were finally included. Except for shorter procedure time in the posterior approach, other factors (pooled difference of LES pressure, Eckardt scores, clinical success, length of total myotomy, hospital stays, gastroesophageal reflux (GERD), and adverse event) were compared, and all above confirmed that there is no difference between anterior and posterior approaches, and the safety of POEM is ensured. In addition, both anterior and posterior myotomy can improve LES pressure and Eckardt scores, and the difference in anterior and posterior myotomy was unconspicuous.

Conclusion

The terms of the pooled difference in LES pressure, Eckardt scores, and other factors (clinical success, length of total myotomy, hospital stays, GERD, adverse events, and procedure time) seemed to be similar for the anterior and posterior approaches. However, the further prognosis after POEM via anterior and posterior approaches needs to be answered in the future.

Modified Peroral Endoscopic Myotomy Technique for Type II Achalasia: A Multicenter Retrospective Study

Aim

This retrospective study is aimed at evaluating the outcomes of a modified peroral endoscopic myotomy (POEM) technique in patients with type II achalasia.

Methods

We performed a modified POEM procedure, which involved a shorter (total myotomy length = 4 cm), full-thickness myotomy, on 31 patients with type II achalasia. Clinical success rates, technical success rates, pre- and postoperative esophageal manometry results, complications, and reflux-related adverse events were evaluated.

Results

The clinical success (Eckardt score ≤ 3) rates were 100% and 88.9% within 2 years and beyond 2 years postoperatively, respectively. The median lower esophageal sphincter pressures (LESP) decreased from 31.6 (26.7-49.7) mmHg preoperatively to 13.4 (10.5-21.6) and 11.8 (7.4-16.7) mmHg (P < 0.001) at 6 and 12 months postoperatively, respectively. The median integrated relaxation pressure (IRP) decreased from 27.8 (20.6-37.5) mmHg preoperatively to 12.9 (11.3-23.4) and 11.6 (9.6-16.8) mmHg (P < 0.001) at 6 and 12 months after POEM, respectively. Only one case (3.2%) of mucosal injury, four (12.9%) cases of reflux esophagitis, and two (6.5%) cases of gastroesophageal reflux symptoms were reported.

Conclusions

The modified POEM technique showed excellent outcomes in patients with type II achalasia.

Per-oral Endoscopic Myotomy: State of the Art

For more than a decade, per-oral endoscopic myotomy (POEM) has been performed for the treatment of achalasia and other dysmotilities of the esophagus. POEM has become an accepted alternative to Heller myotomy, a salvation technique for patients not responding to Heller myotomy and the favorite intervention for diffuse esophageal spasm and jackhammer esophagus. POEM paved the way for endoscopic pyloromyotomy, Zenker's diverticulum myotomy, and submucosal tunneling with endoscopic resection. This review will cover the technique and the most current literature of this revolutionary third space technique.

Peroral endoscopic myotomy (POEM) vs pneumatic dilation (PD) in treatment of achalasia: A meta-analysis of studies with ≥ 12-month follow-up

Background and study aims  Peroral endoscopic myotomy (POEM) is increasingly being used as the preferred treatment option for achalasia. The aim of this systematic review and meta-analysis was to compare the efficacy and safety of POEM versus pneumatic balloon dilation (PD). Methods  We performed a comprehensive review of studies that reported clinical outcomes of POEM and PD for the treatment of achalasia. Measured outcomes included clinical success (improvement of symptoms based on a validated scale including an Eckardt score ≤ 3), adverse events, and post-treatment gastroesophageal reflux disease (GERD). Results  Sixty-six studies (6268 patients) were included in the final analysis, of which 29 studies (2919 patients) reported on POEM and 33 studies (3050 patients) reported on PD and 4 studies (299 patients) compared POEM versus PD. Clinical success with POEM was superior to PD at 12, 24, and 36 months (92.9 %, vs 76.9 % P  = 0.001; 90.6 % vs 74.8 %, P  = 0.004; 88.4 % vs 72.2 %, P  = 0.006, respectively). POEM was superior to PD in type I, II and III achalasia (92.7 % vs 61 %, P  = 0.01; 92.3 % vs 80.3 %, P  = 0.01; 92.3 %v 41.9 %, P  = 0.01 respectively) Pooled OR of clinical success at 12 and 24 months were significantly higher with POEM (8.97; P  = 0.001 & 5.64; P  = 0.006). Pooled OR of GERD was significantly higher with POEM (by symptoms: 2.95, P  = 0.02 and by endoscopic findings: 6.98, P  = 0.001). Rates of esophageal perforation (0.3 % vs 0.6 %, P  = 0.8) and significant bleeding (0.4 % vs 0.7 %, P  = 0.56) were comparable between POEM and PD groups. Conclusions  POEM is more efficacious than PD in the treatment of patients with achalasia during short-term and long-term follow-up, albeit with higher risk of abnormal esophageal acid exposure.

Esophageal POEM: the new standard of care

Since its introduction into clinical practice nearly a decade ago, per-oral endoscopic myotomy (POEM) has now become an accepted minimally invasive approach for the treatment of achalasia with excellent short- and mid-term clinical outcomes in both treatment naïve and those who have failed prior therapy. POEM is comparable to laparoscopic Heller myotomy (LHM) in terms of efficacy and safety, with less procedural pain and faster recovery time. Recent data also reveals that POEM may be more effective and durable than pneumatic dilation (PD) for the treatment of achalasia, with similar safety profile. Preliminary data on POEM for spastic esophageal disorders (SED) is promising yet scarce. Post-POEM gastroesophageal reflux disease (GERD) is common but asymptomatic in most patients, further highlighting the need for ongoing research in this field and the importance of long-term surveillance of these patients.

Feasibility, safety, and long-term efficacy of gastric peroral endoscopic myotomy (G-POEM) for postsurgical gastroparesis: a single-center and retrospective study of a prospective database

BACKGROUND

Postsurgical gastroparesis is recognized as a gastrointestinal dysfunction syndrome following foregut surgery. Gastric peroral endoscopic myotomy (G-POEM) is suggested as a minimally invasive therapy for gastroparesis. But the long-term efficacy and safety of G-POEM in treating postsurgical gastroparesis are rarely explored.

METHODS

The primary outcomes included the symptomatic improvement based on gastroparesis cardinal symptoms index (GCSI) and the improvement of gastric emptying. The secondary outcomes included the improvement of gastroesophageal reflux symptoms and complications of G-POEM.

RESULTS

The severity of postsurgical gastroparesis was not associated with the onset time and the course of the disease. G-POEM significantly reduced GCSI throughout the follow-up period (p < 0.0001). For different anastomotic site, a significant improvement of GCSI was found at 6 month post-G-POEM (F_4,165 = 74.18, p < 0.0001). Subscale analysis of GCSI showed that nausea/vomiting, post-prandial fullness/early satiety, and bloating were improved significantly at 6-month post-G-POEM (p < 0.0001, respectively). Half-emptying and whole-emptying time were significantly shortened in patients with different anastomotic site post-G-POEM (half-emptying time: F_3,174 = 65.44, p < 0.0001; whole-emptying time: F_3,174 = 54.85, p < 0.0001). The emptying of ioversol was obviously accelerated after G-POEM. GCSI wasn't related to pyloric length, pyloric diameter, and thickness of pyloric wall. GERDQ was also used to evaluate the clinical efficacy of G-POEM. For each time points, GERDQ didn't differ significantly in patients with different anastomotic site (F_4,104 = 0.8075, p = 0.5231). For patients with different anastomotic site, GERDQ was improved significantly at different time points (F_4,104 = 59.11, p < 0.0001). The higher the esophageal anastomotic site was, the faster G-POEM improved the symptoms of gastroesophageal reflux. No one required re-hospitalization for any complication.

CONCLUSION

G-POEM is a minimally invasive therapy with long-term effectiveness and safety in treating postsurgical gastroparesis.

Updated Systematic Review of Achalasia, with a Focus on POEM Therapy

AIM

To systematically review clinical presentation, diagnosis, and therapy of achalasia, focusing on recent developments in high-resolution esophageal manometry (HREM) for diagnosis and peroral endoscopic myotomy (POEM) for therapy.

METHODS

Systematic review of achalasia using computerized literature search via PubMed and Ovid of articles published since 2005 with keywords ("achalasia") AND ("high resolution" or "HREM" or "peroral endoscopic myotomy" or "POEM"). Two authors independently performed literature searches and incorporated articles into this review by consensus according to prospectively determined criteria.

RESULTS

Achalasia is an uncommon esophageal motility disorder, usually manifested by dysphagia to solids and liquids, and sometimes manifested by chest pain, regurgitation, and weight loss. Symptoms often suggest more common disorders, such as gastroesophageal reflux disease (GERD), thus often delaying diagnosis. Achalasia is a predominantly idiopathic chronic disease. Diagnosis is typically suggested by barium swallow showing esophageal dilation; absent distal esophageal peristalsis; smoothly tapered narrowing ("bird's beak") at esophagogastric junction; and delayed passage of contrast into stomach. Diagnostic findings at high-resolution esophageal manometry (HREM) include: distal esophageal aperistalsis and integrated relaxation pressure (trough LES pressure during 4 s) > 15 mmHg. Achalasia is classified by HREM into: type 1 classic; type 2 compartmentalized high pressure in esophageal body, and type 3 spastic. This classification impacts therapeutic decisions. Esophagogastroduodenoscopy is required before therapy to assess esophagus and esophagogastric junction and to exclude distal esophageal malignancy. POEM is a revolutionizing achalasia therapy. POEM creates a myotomy via interventional endoscopy. Numerous studies demonstrate that POEM produces comparable, if not superior, results compared to standard laparoscopic Heller myotomy (LHM), as determined by LES pressure, dysphagia frequency, Eckardt score, hospital length of stay, therapy durability, and incidence of GERD. Other therapies, including botulinum toxin injection and pneumatic dilation, have moderately less efficacy and much less durability than POEM.

CONCLUSION

This comprehensive review suggests that POEM is equivalent or perhaps superior to LHM for achalasia in terms of cost efficiency, hospital length of stay, and relief of dysphagia, with comparable side effects. The data are, however, not conclusive due to sparse long-term follow-up and lack of randomized comparative clinical trials. POEM therapy is currently limited by a shortage of trained endoscopists.

Difficult peroral endoscopic myotomy: definition and management strategies

Introduction: Peroral endoscopic myotomy (POEM) has been established as an alternative endoscopic method for the treatment of achalasia, and several studies have confirmed its relatively long-term efficacy. Although most of the POEM procedures can be smoothly completed, technical difficulties do arise during the treatment of some patients, which may lead to prolonged procedure duration, increased procedure-related complications, or even aborted POEM.Area covered: In the present review, we provide a comprehensive review of difficult POEM, focusing on its definition, risk factors, and intraoperative management strategies. The present review is expected to provide tips for not so experienced operators who perform POEM.Expert commentary: Submucosal fibrosis and sigmoid-type esophagus are associated with difficult POEM. Sometimes, the following may also be associated with difficult POEM: previous endoscopic or surgical treatments, spastic esophageal disorders (type III achalasia, distal esophageal spasm, and hypercontractile esophagus), achalasia with diverticulum or situs inversus. For operators who begin to perform POEM, I suggest an exclusion of patients with severe submucosal fibrosis or sigmoid-type esophagus, and begin to perform POEM for these patients when they have completed at least 50 cases of 'easy POEM' and the proposed management strategies may be helpful.

Per-oral endoscopic myotomy and gastroesophageal reflux: Where do we stand after a decade of "POETRY"?

Per-oral endoscopic myotomy (POEM) was introduced nearly a decade ago. Since then, the literature on its safety and efficacy has been ever increasing. Initial studies focused solely on the feasibility and efficacy of this procedure in patients with idiopathic achalasia. Subsequent studies analyzed the incidence of gastroesophageal reflux disease (GERD) in addition to the efficacy of POEM. These studies depict a high incidence of GERD after POEM. However, vast majority of these studies lacked a comprehensive evaluation of GERD after POEM. Consequently, it is difficult to provide a true estimate of the incidence of GERD in these patients. Majority of the patients with post-POEM GERD are asymptomatic and those with symptoms usually respond well to proton pump inhibitors. However, the long-term consequences of asymptomatic GERD with increased esophageal acid exposure are not well known. These patients should probably undergo regular surveillance due to theoretical risks of complications like Barrett's esophagus and esophageal adenocarcinoma. It should be acknowledged that there is no well-controlled study to support the strategy of surveillance in this group of patients. Given the high incidence of GERD after POEM, it is time to devise minimally invasive novel strategies to prevent and manage post-POEM GERD. The current literature suggests that the technique of POEM and other factors like type of achalasia do not influence the occurrence of GERD after POEM. Therefore, the endoscopists will need to think out of the box to prevent post-POEM GERD.

The 2 years' long-term efficacy and safety of peroral endoscopic myotomy for the treatment of achalasia: a systematic review

AIM

In this retrospective review, we aimed to investigate the long-term efficacy and safety of POEM with follow-up period over 2 years.

MATERIALS AND METHODS

A systematic review related to POEM for achalasia was conducted. A literature search was performed in Pubmed, Medline, Ovid, Cochrane and EBSCO databases on November 2017. The following postoperative outcomes were extracted: Eckardt score, lower esophageal sphincter pressure, complications and clinical success.

RESULTS

The total number of patients was 373. The mean operative time was 66.7 min and the overall rate of complications was 21.2%. The mean follow-up period was 30.0 months. The overall clinical success rate was 92.9% and the rate of gastroesophageal reflux disease was 10.2%. Rate of mortality after POEM was 0.

CONCLUSIONS

Our study demonstrated that POEM is effective and safe for treating achalasia during the long-term followed up over 2 years.

Efficacy of anterior versus posterior per-oral endoscopic myotomy for treating achalasia: a randomized, prospective study

BACKGROUND AND AIMS

Per-oral endoscopic myotomy (POEM) has been demonstrated to be safe and effective for treating achalasia. Two approaches-anterior myotomy and posterior myotomy-are used during POEM. However, little is known about the comparison between the 2 different approaches. The objective of the study is to compare the safety and short-term efficacy of the 2 approaches for treating achalasia.

METHODS

From October 2015 to December 2016, 63 consecutive patients with achalasia without prior treatment or sigmoid-type esophagus were prospectively recruited. They were randomly assigned to an anterior or posterior myotomy group. Clinical data about general characteristics, operative parameters, pre- and postoperative Eckardt score, esophageal manometry results, 24-hour pH test, and adverse events were recorded and compared between the 2 groups.

RESULTS

The anterior group included 31 patients and the posterior group 32 patients. All patients underwent POEM successfully, and treatment success (defined as an Eckardt score ≤3) was achieved in all patients during a mean follow-up of 15.5 months. Mean Eckardt score, lower esophageal sphincter pressure, and 4-second integrated relaxation pressure were significantly decreased (6.2 ± 1.3, 37.5 ± 6.7 mm Hg, and 27.3 ± 4.9 mm Hg vs .70 ± .70, 12.8 ± 2.8 mm Hg, and 11.1 ± 2.3 mm Hg, respectively; P < .01). There was no significant difference between the 2 groups in terms of general characteristics, treatment success, pre- and postoperative esophageal manometry, Eckardt score, and adverse events (P > .05).

CONCLUSIONS

The short-term treatment efficacy, manometry outcomes, and adverse events were comparable between the anterior and posterior myotomy groups. Large-scale studies with long-term follow-up are warranted for a more definitive conclusion. (Clinical trial registration number: ChiCTR-ICR-15007211.).

Adverse events during and after per-oral endoscopic myotomy: prevention, diagnosis, and management

Per-oral endoscopic myotomy (POEM) has surfaced as an effective endoscopic treatment modality for achalasia cardia (AC). Promising results in short- and mid-term follow-up studies have increased the use of POEM for the management of AC. POEM can be safely performed in an endoscopy suit, and major adverse events (AEs) are uncommon. AEs encountered during POEM or during the perioperative period principally include insufflation-related AEs, mucosal injuries, bleeding, pain, and aspiration pneumonia. Most insufflation-related AEs do not require an active intervention and therefore should not be considered as AEs in the true sense. When management of AEs is required, most intraoperative AEs can be managed at the same time without untoward consequences. Occurrences of AEs lessen after completion of the learning curve. However, experience alone does not ensure "zero" incidence of AEs, and early recognition remains essential. Postoperative AEs, like leaks, delayed bleeding, and delayed mucosal perforations, may pose special challenges for diagnosis and management. There is no standardized classification system for grading the severity of AEs associated with POEM, resulting in wide variation in their reported occurrences. Uniform reporting of AEs is not only crucial to comprehensively analyze the safety of POEM but also for comparison with other established treatment modalities like Heller's myotomy. GERD is an important long-term AE after POEM. Unlike the perioperative AEs, little is known regarding the intraoperative or patient-related factors that influence the occurrence of post-POEM GERD. Large prospective studies with long-term follow-up are required to determine the procedural factors associated with GERD after POEM.

Clinical Practice Update: The Use of Per-Oral Endoscopic Myotomy in Achalasia: Expert Review and Best Practice Advice From the AGA Institute

The purpose of this review is to describe a place for per-oral endoscopic myotomy (POEM) among the currently available robust treatments for achalasia. The recommendations outlined in this review are based on expert opinion and on relevant publications from PubMed and EMbase. The Clinical Practice Updates Committee of the American Gastroenterological Association proposes the following recommendations: 1) in determining the need for achalasia therapy, patient-specific parameters (Chicago Classification subtype, comorbidities, early vs late disease, primary or secondary causes) should be considered along with published efficacy data; 2) given the complexity of this procedure, POEM should be performed by experienced physicians in high-volume centers because an estimated 20-40 procedures are needed to achieve competence; 3) if the expertise is available, POEM should be considered as primary therapy for type III achalasia; 4) if the expertise is available, POEM should be considered as treatment option comparable with laparoscopic Heller myotomy for any of the achalasia syndromes; and 5) post-POEM patients should be considered high risk to develop reflux esophagitis and advised of the management considerations (potential indefinite proton pump inhibitor therapy and/or surveillance endoscopy) of this before undergoing the procedure.