Peroral endoscopic myotomy (POEM) is an established treatment for achalasia, yet there is still a lack of technical standardization. No clear definition of \'long\', \'standard\', or \'short\' POEM exists to date. We conducted a systematic review with meta-analysis to analyze current POEM length standards. We included studies reporting technical details of POEM, in which no definite or comparative myotomy length was intentionally adopted (standard myotomy). The primary outcome was the pooled mean total myotomy length. Sub-group analyses were performed to explore heterogeneity across studies. From the initial 7172 records, 31 studies with 3023 patients were included. Pooled mean of total myotomy length was 10.39 cm (95% CI 10.06-10.71; I2 99.3%). Pooled mean of esophageal and gastric myotomy length, provided by 17 studies, was 7.11 cm (95% CI 6.51-7.71; I2 99.8%) and 2.81 cm (95% CI 2.41-3-22; I2 99.8%), respectively. On subgroup analysis for achalasia subtypes, pooled mean length in non-spastic achalasia (type I and II) was 10.17 cm (95% CI 9.91-10.43; I2 94.2%), while in type III it was 14.02 cm (95% CI 10.59-17.44; I2 98.9%). Pooled mean myotomy length for studies conducted between 2014-2020 was 10.53 cm (95% CI, 10.22-10.84; I2 99.1%) and 9.74 cm (95% CI, 7.95-11.54; I2 99.7%) in 2021-2022. Myotomy length during a \'standard\' POEM is 10.4 cm, remaining over 10 cm in non-spastic achalasia. The high heterogeneity across studies confirms that the POEM technique needs further standardization. We found no significant time trend towards adopting short POEM, despite recent evidence supporting its use.

Esophageal diverticulum is a rare condition characterized by the herniation of the esophageal mucosa outside the esophageal wall. Here, we explore the prevalence of ED and its associated esophageal dysmotility. We also shed light on the potential impact of previous surgical interventions, such as Nissen\'s fundoplication, on the development of ED. This manuscript presents the case of a 72-year-old woman with a history of Nissen\'s fundoplication surgery who experienced worsening symptoms of dysphagia, heartburn and postprandial cough. Despite exhibiting a normal motility pattern, upper endoscopy revealed a large epiphrenic esophageal diverticulum. The patient underwent successful surgical resection with myotomy, resulting in the resolution of symptoms with no complications. This case highlights the rarity of symptomatic ED and the need to recognize it while choosing the optimal treatment modality.

BACKGROUND: Peroral endoscopic myotomy (POEM) is an emerging effective treatment for achalasia. However, a significant proportion of patients do not respond well to the treatment. After over a decade of clinical practice, potential risk factors associated with POEM failure have been identified. This meta-analysis aimed to summarize the evidence of risk factors for POEM failure.
METHODS: A systematic literature search was conducted on PubMed, Embase, Web of Science, and Cochrane Library from inception to June 10th, 2022. We included English studies that reported POEM outcomes in achalasia patients and identified risk factors for POEM failure. Relevant information was extracted and analyzed using fixed- or randomized-effect models to pool the effect size.
RESULTS: A total of 27 studies comprising 9371 patients with achalasia were included in this review. The pooled failure rate was 8% (90% CI 7%-10%). We identified sigmoid esophagus (OR 1.90, 95% CI 1.45-2.47), type I achalasia (OR 1.30, 95% CI 1.04-1.63), and type III achalasia (OR 1.26, 95% CI 0.89-1.78) were associated with a worse clinical response. Conversely, type II achalasia was associated with a better response (OR 0.59, 95% CI 0.47-0.75). Prior treatment with Heller myotomy (OR 5.75, 95% CI 3.97-8.34) and prior balloon dilation (OR 1.18, 95% CI 1.07-1.29) were also associated with a higher risk of clinical failure.
CONCLUSIONS: Our meta-analysis results demonstrated that sigmoid esophagus, manometric achalasia subtype, and prior treatment were associated with POEM failure. This information could be used to guide treatment decisions and improve the success rate of POEM in achalasia patients.

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.

Our review delves into the realm of peroral endoscopic myotomies (POEMs) in the upper gastrointestinal tract (UGT). In recent years, POEMs have brought about a revolution in the treatment of UGT motility disorders. Esophageal POEM, the first to be introduced, has now been validated as the primary treatment for achalasia. Subsequently developed, G-POEM displays promising results in addressing refractory gastroparesis. Over time, multiple endoscopic myotomy techniques have emerged for the treatment of Zenker\'s diverticulum, including Z-POEM, POES, and hybrid approaches. Despite the well-established efficacy outcomes, new challenges arise in the realm of POEMs in the UGT. For esophageal POEM, the future scenario lies in customizing the myotomy extent to the minimum necessary, while for G-POEM, it involves identifying patients who can optimally benefit from the treatment. For ZD, it is crucial to validate an algorithm that considers various myotomy options according to the diverticulum\'s size and in relation to individual patients. These challenges align with the concept of precision endoscopy, personalizing the technique for each subject. Within our text, we comprehensively examine each myotomy technique, analyzing indications, outcomes, and adverse events. Additionally, we explore the emerging challenges posed by myotomies within the context of the evolving field of precision endoscopy.

This mini-review summarizes the most recent literature regarding per-oral endoscopic myotomy for type III achalasia, emphasizing the poorly understood science of tailoring myotomy length during this procedure. In addition, special attention will be placed on the current subjective and objective biomarkers, such as the Eckardt score, used to evaluate treatment outcomes in this population to better contextualize the existing data on patient outcomes, as proposed by Low et al in the current issue of the Journal. Understanding the current treatment landscape for type III achalasia and identifying the key areas of research deficiencies will guide future investigation and management of this disease.

Peroral endoscopic myotomy (POEM) is an intervention for the treatment of achalasia which has gained popularity over the last decade. It\'s efficacy and invasiveness are comparable to laparoscopic Heller myotomy (LHM). The purpose of this systematic review is to compare POEM to existing therapies. The systematic review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. MEDLINE, EMBASE, Web of Science and Cochrane Libraries were searched using keywords: esophageal achalasia, POEM, LHM, pneumatic dilation (PD), and related terms. The studied outcomes were Eckardt score, clinical success, hospital stay, cost-utility analysis, complications, and post-treatment gastro-esophageal reflux disease. Articles were reviewed by one researcher and uncertainty was resolved by a second researcher. The search strategy retrieved 1948 citations. After removing duplicates and applying the exclusion criteria, 91 studies were selected for full-text review of which a total of 31 studies were considered eligible for further analysis, including two studies which were found through manual searching. POEM has improved efficacy compared to PD with similar cost-effectiveness. POEM results showed comparable patient outcomes when compared with laparoscopic myotomy. Overall, POEM is a feasible first-line treatment for achalasia.

Post-lung transplant gastroparesis is a frequent debilitating complication of lung transplant recipients, as it can increase the risk for gastro-esophageal reflux disease and subsequent graft dysfunction. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of GPOEM in lung transplant patients with refractory gastroparesis.
The present systematic review and meta-analysis wer performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We selected studies that analyzed the gastroparesis cardinal symptom index (GCSI) before and after the procedure to verify the efficacy of GPOEM. Random-effects model was used and the analysis was performed with STATA 17.
Four observational studies (one conference abstract) with 104 patients were included in the meta-analysis. Prior treatments for gastroparesis included prokinetic agents and botulinum toxin in 78% (78/104) and 66.7% (66/99), respectively. Pooled estimate for clinical efficacy of GPOEM was 83% (95% CI 76%-90%). The pooled mean reduction in GCSI following the procedure was - 2.01 (- 2.35, - 1.65, p = 0.014). Three studies reported statistically significant improvement of gastro-esophageal retention or emptying in the post-GPOEM period. 30-day post-operative complications included minor or major bleeding (11.6%), severe reflux (1.2%), and pyloric stenosis (1.2%) requiring re-intervention. 90-day all-cause mortality was 2.6% with one patient dying from severe allograft rejection.
Our study showed that GPOEM is an effective and safe strategy for lung transplant patients with refractory gastroparesis and should be considered as a therapeutic strategy in this population. Larger multicenter trials are needed in the future to further evaluate the effect of GPOEM on allograft function and rates of rejection.

Gastric Per-Oral Endoscopic Myotomy (GPOEM) has been developed as an effective treatment option for patients with medically refractory gastroparesis. Other endoscopic options, such as pyloric injection of botulinum toxin (Botox), is often performed with limited efficacy. The purpose of this study was to evaluate GPOEM for the treatment of gastroparesis and compare its efficacy to Botox injection results reported in the literature.
A retrospective review was conducted to identify all patients who underwent a GPOEM for the treatment of gastroparesis between September 2018 and June 2022. Changes in Gastric Emptying Scintigraphy (GES) studies and Gastroparesis Cardinal Symptom (GCSI) scores from the preoperative to postoperative period were analyzed. In addition, a systematic review was conducted to identify all publications reporting the outcomes of Botox injections for the treatment of gastroparesis.
A total of 65 patients (51 female, 14 male) underwent a GPOEM during the study period. Twenty-eight patients (22 female, 6 male) had both preoperative and postoperative GES studies in addition to GCSI scores. The etiologies of gastroparesis were diabetic (n = 4), idiopathic (n = 18), and postsurgical (n = 6). Fifty percent of these patients had undergone previous failed interventions including Botox injections (n = 6), gastric stimulator placement (n = 2), and endoscopic pyloric dilation (n = 6). Outcomes showed a significant decrease in GES percentages (mean difference = - 23.5%, p < 0.001) and GCSI scores (mean difference = - 9.6, p = 0.02) postoperatively. In the systematic review for Botox, transient mean improvements in postoperative GES percentages and GCSI scores were reported at 10.1% and 4.0, respectively.
GPOEM leads to significant improvement in GES percentages and GCSI scores postoperatively and is superior to Botox injection results reported in the literature.

BACKGROUND: Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a relatively newly identified clinical condition that manifests as trismus with a square-shaped mandible. Herein, we report a case of MMATH that was initially misdiagnosed for polymyositis due to trismus and simultaneous lower limb pain, with literature review.
METHODS: A 30-year-old woman had a history of lower limb pain after exertion for 2 years. Initial physical examination had been performed at the Department of General Medicine in our hospital. There was also redness in the hands and fingers. Although polymyositis was suspected, it was denied. The patient visited our department for right maxillary wisdom tooth extraction. Clinical examination revealed that the patient had a square-shaped mandible. The maximal mouth opening was 22 mm. There was no temporomandibular joint pain at the time of opening. Furthermore, there was awareness of clenching while working. Panoramic radiography revealed developed square mandibular angles with flattened condyles. Computed tomography showed enlarged masseter muscles with high-density areas around the anterior and lateral fascia. Magnetic resonance imaging also showed thickened tendons and aponeuroses on the anterior surface and inside bilateral masseter muscles. Finally, the patient was diagnosed with MMTAH. Bilateral aponeurectomy of the masseter muscles with coronoidectomy and masseter muscle myotomy was performed under general anesthesia. The maximum opening during surgery was 48 mm. Mouth opening training was started on day 3 after surgery. Histopathological examination of the surgical specimen showed that the muscle fibers were enlarged to 60 μm. Immunohistochemistry testing for calcineurin, which was associated with muscle hypertrophy due to overload in some case reports, showed positive results. Twelve months after surgery, the mouth self-opening and forced opening were over 35 mm and 44 mm, respectively.
CONCLUSIONS: Herein, we report a case of MMATH. Lower limb pain due to prolonged standing at work and overload due to clenching were considered risk factors for symptoms onset of MMATH.