Novel scale for evaluating the therapeutic efficacy of per-oral endoscopic myotomy in achalasia.

BACKGROUND: Symptom scales for achalasia after per-oral endoscopic myotomy (POEM) are lacking. This study aimed to propose a new scale based on the conventional Eckardt score (c-ES) and evaluate persistent symptoms that impair patients' quality of life (QOL) post-POEM. METHODS: Dysphagia, regurgitation, and chest pain frequencies were assessed using a 6-point scale modified-ES (m-ES) after POEM, with "occasional" symptoms on the c-ES further subdivided into three-period categories on m-ES. Symptom severity was further evaluated using a 5-point scale ranging from 1 to 5 points, with a score ≥ 3 points defined as persistent symptoms impairing QOL. We analyzed the correlation between the m-ES and severity score, diagnostic performance of the m-ES for persistent symptoms, and overlaps between each residual symptom. RESULTS: Overall, 536 patients (median follow-up period, 2.9 years) post-POEM were included in this multicenter study. Significant correlations were observed between the m-ES and severity scores for dysphagia (r = 0.67, p < 0.01), regurgitation (r = 0.73, p < 0.01), and chest pain (r = 0.85, p < 0.01). Twenty-six patients (4.9%) had persistent symptoms post-POEM, and 23 of them had m-ES-specific symptom frequency ≥ once a month, which was determined as the optimal frequency threshold for screening persistent symptoms. The total m-ES predicted persistent symptoms more accurately than the total c-ES (area under the curve: 0.95 vs. 0.79, p < 0.01). Furthermore, dysphagia and chest pain were the major residual symptoms post-POEM covering 91.4% of regurgitation. CONCLUSIONS: The new post-POEM scale successfully evaluated the QOL-based patient symptom severities. Our study implied the possibility of a simpler scale using residual dysphagia and chest pain.

The interplay between alterations in esophageal microbiota associated with Th17 immune response and impaired LC20 phosphorylation in achalasia.

BACKGROUND: Achalasia is an esophageal motility disorder with an unknown etiology. We aimed to determine the pathogenesis of achalasia by studying alterations in esophageal smooth muscle contraction and the associated inflammatory response, and evaluate the role of esophageal microbiota in achalasia development. METHODS: We analyzed esophageal mucosa and lower esophageal sphincter (LES) samples, obtained from patients with type II achalasia who underwent peroral endoscopic myotomy. Esophageal conditioned media obtained from patients were transferred into the mouse esophagus to determine whether the esophageal intraluminal environment is associated with achalasia. RESULTS: Approximately 30% of 20-kDa myosin light chains (LC20) was phosphorylated in LES from the control group under resting and stimulated conditions, whereas less than 10% of LC20 phosphorylation was detected in achalasia under all conditions. The hypophosphorylation of LC20 in achalasia was associated with the downregulation of the myosin phosphatase-inhibitor protein CPI-17. Th17-related cytokines, including IL-17A, IL-17F, IL-22, and IL-23A, were significantly upregulated in achalasia. α-Diversity index of esophageal microbiota and the proportion of several microbes, including Actinomyces and Dialister, increased in achalasia. Actinomyces levels positively correlated with IL-23A levels, whereas Dialister levels were positively associated with IL-17A, IL-17F, and IL-22 levels. Esophageal IL-17F levels increased in mice after oral administration of the conditioned media. CONCLUSIONS: In LES of patients with achalasia, hypophosphorylation of LC20, a possible cause of impaired contractility, was associated with CPI-17 downregulation and an increased Th17-related immune response. The esophageal intraluminal environment, represented by the esophageal microbiota, could be associated with the development and exacerbation of achalasia.

Comparison of hemostatic ability between spray coagulation and forced coagulation modes in endoscopic submucosal dissection in patients with early gastric neoplasms: a study protocol for multicenter randomized controlled trial (Spray-G trial).

BACKGROUND: Endoscopic submucosal dissection (ESD) is the standard treatment for early gastric neoplasms (EGN). Controlling intraoperative bleeding is crucial for ensuring safe and reliable procedures. ESD using the spray coagulation mode (SCM-ESD) has been developed to control bleeding more effectively than ESD using the conventional forced coagulation mode (FCM-ESD). This study aims to compare the hemostatic efficacies of SCM-ESD and FCM-ESD. METHODS: This multicenter, prospective, parallel, randomized, open-label superiority trial will be conducted in five Japanese institutions. Patients with a preoperative diagnosis of intramucosal EGC will be randomized to undergo either SCM-ESD or FCM-ESD. The primary outcome measure is the completion of ESD with an electrosurgical knife alone, without the use of hemostatic forceps. Secondary outcomes include the number and duration of hemostasis using hemostatic forceps, procedure time, curability, and safety. A total of 130 patients will be enrolled in this study. DISCUSSION: This trial will provide evidence on the hemostatic efficacy of SCM-ESD compared with FCM-ESD in patients with intramucosal EGN, potentially improving the safety and reliability of ESD procedures. TRIAL REGISTRATION: The trial has been registered at the University Hospital Medical Information Network Clinical Trials Registration (UMIN-CTR) as UMIN000040518. The reception number is R000054009.

Development of a new endoscopy system to visualize bilirubin for the diagnosis of duodenogastroesophageal reflux.

OBJECTIVES: Reflux hypersensitivity (RH) is a form of refractory gastroesophageal reflux disease in which duodenogastroesophageal reflux (DGER) plays a role. This study aimed to determine the usefulness of an endoscopy system equipped with image-enhanced technology for evaluating DGER and RH. METHODS: The image enhancement mode for detecting bilirubin and calculated values were defined as the Bil mode and Bil value, respectively. First, the visibility of the Bil mode was validated for a bilirubin solution and bile concentrations ranging from 0.01% to 100% (0.002-20 mg/dL). Second, visibility scores of the Bil mode, when applied to the porcine esophagus sprayed with a bilirubin solution, were compared to those of the blue laser imaging (BLI) and white light imaging (WLI) modes. Third, a clinical study was conducted to determine the correlations between esophageal Bil values and the number of nonacid reflux events (NNRE) during multichannel intraluminal impedance-pH monitoring as well as the utility of esophageal Bil values for the differential diagnosis of RH. RESULTS: Bilirubin solution and bile concentrations higher than 1% were visualized in red using the Bil mode. The visibility score was significantly higher with the Bil mode than with the BLI and WLI modes for 1% to 6% bilirubin solutions (P < 0.05). The esophageal Bil value and NNRE were significantly positively correlated (P = 0.031). The area under the receiver operating characteristic curve for the differential diagnosis of RH was 0.817. CONCLUSION: The Bil mode can detect bilirubin with high accuracy and could be used to evaluate DGER in clinical practice.

Achalasia phenotypes and prediction of peroral endoscopic myotomy outcomes using machine learning.

OBJECTIVES: High-resolution manometry (HRM) and esophagography are used for achalasia diagnosis; however, achalasia phenotypes combining esophageal motility and morphology are unknown. Moreover, predicting treatment outcomes of peroral endoscopic myotomy (POEM) in treatment-naïve patients remains an unmet need. METHODS: In this multicenter cohort study, we included 1824 treatment-naïve patients diagnosed with achalasia. In total, 1778 patients underwent POEM. Clustering by machine learning was conducted to identify achalasia phenotypes using patients' demographic data, including age, sex, disease duration, body mass index, and HRM/esophagography findings. Machine learning models were developed to predict persistent symptoms (Eckardt score ≥3) and reflux esophagitis (RE) (Los Angeles grades A-D) after POEM. RESULTS: Machine learning identified three achalasia phenotypes: phenotype 1, type I achalasia with a dilated esophagus (n = 676; 37.0%); phenotype 2, type II achalasia with a dilated esophagus (n = 203; 11.1%); and phenotype 3, late-onset type I-III achalasia with a nondilated esophagus (n = 619, 33.9%). Types I and II achalasia in phenotypes 1 and 2 exhibited different clinical characteristics from those in phenotype 3, implying different pathophysiologies within the same HRM diagnosis. A predictive model for persistent symptoms exhibited an area under the curve of 0.70. Pre-POEM Eckardt score ≥6 was the greatest contributing factor for persistent symptoms. The area under the curve for post-POEM RE was 0.61. CONCLUSION: Achalasia phenotypes combining esophageal motility and morphology indicated multiple disease pathophysiologies. Machine learning helped develop an optimal risk stratification model for persistent symptoms with novel insights into treatment resistance factors.

Risk scoring system for the preprocedural prediction of the clinical failure of peroral endoscopic myotomy: a multicenter case-control study.

BACKGROUND: Peroral endoscopic myotomy (POEM) is effective for the management of achalasia and its variants; however, it can be ineffective in some patients. We aimed to develop and validate a risk scoring system to predict the clinical failure of POEM preoperatively. METHODS: Consecutive patients who underwent POEM in 14 high volume centers between 2010 and 2020 were enrolled in this study. Clinical failure was defined as an Eckardt score of ≥ 4 or retreatment. A risk scoring system to predict the short-term clinical failure of POEM was developed using multivariable logistic regression and internally validated using bootstrapping and decision curve analysis. RESULTS: Of the 2740 study patients, 112 (4.1 %) experienced clinical failure 6 months after POEM. Risk scores were assigned for three preoperative factors as follows: preoperative Eckardt score (1 point), manometric diagnosis (-4 points for type II achalasia), and a history of prior treatments (1 point for pneumatic dilation or 12 points for surgical/endoscopic myotomy). The discriminative capacity (concordance statistics 0.68, 95 %CI 0.62-0.72) and calibration (slope 1.15, 95 %CI 0.87-1.40) were shown. Decision curve analysis demonstrated its clinical usefulness. Patients were categorized into low (0-8 points; estimated risk of clinical failure < 5 %) and high risk (9-22 points; ≥ 5 %) groups. The proportions of clinical failure for the categories were stratified according to the mid-term outcomes (log-rank test, P < 0.001). CONCLUSIONS: This risk scoring system can predict the clinical failure of POEM preoperatively and provide useful information when making treatment decisions.

Ampullary Neuroendocrine Neoplasm: Clinicopathological Characteristics and Novel Endoscopic Entity.

BACKGROUND: Neuroendocrine neoplasms of the ampulla of Vater (ampullary NEN) have features of both gastrointestinal and pancreato-biliary (PB) NEN. However, the limited number of studies examining ampullary NEN makes it difficult to clarify their unique characteristics. This study aimed to elucidate the clinical characteristics of ampullary NEN. METHODS: We enrolled 162 patients with PB-NEN diagnosed at Kyushu University Hospital between 2011 and 2020. Clinical features, pathological diagnoses, treatments, and prognoses were retrospectively analyzed. We also compared ampullary NEN with pancreatic NEN (PanNEN). RESULTS: We analyzed 10 ampullary NEN cases and 149 PanNEN cases. The ampullary NEN cases consisted of 4 cases of neuroendocrine tumor Grade 1 (NET G1), 1 NET G2 (Grade 2), and 5 neuroendocrine carcinomas (NECs). The incidences of NEC and cholangitis were significantly higher in ampullary NEN than in PanNEN. All ampullary NETs had a submucosal tumor-like appearance, as identified by endoscopic ultrasound-guided fine needle aspiration. We treated small NET G1 (<10 mm) with endoscopic papillectomy and large NET G1 with pancreaticoduodenectomy. There were no cases of recurrence after resection. All ampullary NECs presented with the characteristic endoscopic finding of a "crater sign" similar to deep-mining ulcers seen in gastric malignant lymphoma. Four cases underwent surgical resection, and 1 case was unresectable. Two patients who underwent multidisciplinary treatment were maintained without recurrence for over 2 years. CONCLUSIONS: Endoscopic findings showed identifiable distinctions between ampullary NETs and NECs.

Impact of peroral endoscopic myotomy on high-resolution manometry findings and their association with the procedure's outcomes.

BACKGROUND AND AIMS: Peroral endoscopic myotomy (POEM) is conducted for patients with esophageal motility disorders based on high-resolution manometry (HRM) findings. However, the impact of POEM on HRM findings and the associations between post-POEM HRM and outcomes have not been clarified. METHODS: In a multicenter, observational, cohort study, patients with achalasia treated by POEM received follow-up HRM. Associations between patient characteristics, POEM procedures, and post-POEM HRM findings, including integrated relaxation pressure (IRP) and distal contractile integral (DCI), were investigated. Furthermore, POEM procedure outcomes were compared with post-POEM HRM findings. RESULTS: Of 2171 patients, 151 (7.0%) showed residual high post-POEM IRP (≥26 mm Hg; Starlet [Starmedical Ltd, Tokyo, Japan]). In a multivariate analysis, high pre-POEM IRPs (odds ratio [OR], 24.3) and gastric myotomy >2 cm (OR, .22) were found to be positive and negative predictive factors of high post-POEM IRPs, respectively. Peristalsis recovery (DCI ≥500 mm Hg/cm/s, at least 1 swallow; Starlet) was visible in 121 of 618 patients (19.6%) who had type II to III achalasia. High pre-POEM IRP (OR, 2.65) and DCI ≥500 (OR, 2.98) predicted peristalsis recovery, whereas esophageal dilation (OR, .42) predicted a risk of no recovery. Extended myotomy did not reveal a significant impact on peristalsis recovery. High or low post-POEM IRP and DCI did not increase the incidence of clinical failure, reflux esophagitis, or symptomatic GERD. CONCLUSIONS: Extended gastric myotomy decreased IRP values, whereas peristalsis recovery depended on the characteristics of achalasia. A residual high post-POEM IRP does not necessarily mean clinical failure. Routine HRM follow-up is not recommended after POEM.

Subtype of Achalasia and Integrated Relaxation Pressure Measured Using the Starlet High-resolution Manometry System: A Multicenter Study in Japan.

Background/Aims: ManoScan and Sandhill high-resolution manometry (HRM) systems are used worldwide; however, the diagnosis of achalasia on the Starlet HRM system is not fully characterized. Furthermore, the impact of calcium channel blockers and nitrites in treating achalasia has not been investigated using HRM. Management of recurrent cases is a priority issue, although few studies have examined patient characteristics. Methods: We conducted a multicenter, large-scale database analysis. First, the diagnosis of treatment-naive achalasia in each HRM system was investigated. Next, patient characteristics were compared between type I-III achalasia, and the impact of patient characteristics, including calcium channel blocker and nitrite use for integrated relaxation pressure (IRP) values, were analyzed. Finally, patient characteristics with recurrent achalasia were elucidated. Results: The frequency of type I achalasia with Starlet was significantly higher than that with ManoScan and Sandhill HRM systems. In achalasia, multivariate analysis identified male sex, advanced age, long disease duration, obesity, type I achalasia, and sigmoid type as risk factors related to normal IRP values (< 26 mmHg). Calcium channel blockers and nitrites use had no significant impact on the IRP values, although achalasia symptoms were indicated to be alleviated. In recurrent cases, the IRP value was significantly lower, and advanced age, long disease duration, and sigmoid type were more common than in treatment-naive patients. Conclusions: We should cautiously interpret the type of achalasia and IRP values in the Starlet HRM system. Symptoms of recurrent cases are related to disease progression rather than IRP values, which should be considered in decision making.

Efficacy of ultrasound endoscopy with artificial intelligence for the differential diagnosis of non-gastric gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are common subepithelial lesions (SELs) and require treatment considering their malignant potential. We recently developed an endoscopic ultrasound-based artificial intelligence (EUS-AI) system to differentiate GISTs from non-GISTs in gastric SELs, which were used to train the system. We assessed whether the EUS-AI system designed for diagnosing gastric GISTs could be applied to non-gastric GISTs. Between January 2015 and January 2021, 52 patients with non-gastric SELs (esophagus, n = 15; duodenum, n = 26; colon, n = 11) were enrolled. The ability of EUS-AI to differentiate GISTs from non-GISTs in non-gastric SELs was examined. The accuracy, sensitivity, and specificity of EUS-AI for discriminating GISTs from non-GISTs in non-gastric SELs were 94.4%, 100%, and 86.1%, respectively, with an area under the curve of 0.98 based on the cutoff value set using the Youden index. In the subanalysis, the accuracy, sensitivity, and specificity of EUS-AI were highest in the esophagus (100%, 100%, 100%; duodenum, 96.2%, 100%, 0%; colon, 90.9%, 100%, 0%); the cutoff values were determined using the Youden index or the value determined using stomach cases. The diagnostic accuracy of EUS-AI increased as lesion size increased, regardless of lesion location. EUS-AI based on gastric SELs had good diagnostic ability for non-gastric GISTs.

Improved esophagography screening for esophageal motility disorders using wave appearance and supra-junctional ballooning.

BACKGROUND: High-resolution manometry (HRM) is the gold standard for diagnosing esophageal motility disorders (EMDs); however, it requires specialized equipment. The development of more accessible screening examinations is expected. We evaluated the utility of barium esophagography (BE) screening using two novel findings to diagnose EMDs. METHODS: Between January 2013 and October 2020, 244 patients with suspected EMDs who underwent both HRM and BE were analyzed. The EMD diagnosis was based on HRM findings using Chicago Classification version 3.0. BE was performed using sequential esophagography with barium sulfate. Three conventional BE findings (air-fluid level, rosary-bead/corkscrew appearance, and absent/weak peristalsis) and two novel BE findings (wave appearance and supra-junctional ballooning) were used for diagnosis. RESULTS: The sensitivity and specificity of BE screening using the two novel findings and conventional findings to diagnose EMDs were 79.4% and 88%, respectively [area under the receiver-operating characteristic curve (AUC) = 0.837]. Without these novel findings, they were 63.9% and 96%, respectively (AUC = 0.800), respectively. Achalasia was highly correlated with the air-fluid level (88.7%). Absent contractility was highly correlated with absent/weak peristalsis (85.7%). Relatively high correlations were observed between distal esophageal spasm and rosary-bead/corkscrew appearance (60%), and between achalasia and wave appearance (59.7%). The intra-observer reproducibility and inter-observer agreement for individual BE findings were 84.4% and 75%, respectively. Wave appearance was associated with higher integrated relaxation pressure (IRP) and shorter distal latency. Supra-junctional ballooning was associated with higher IRP. CONCLUSIONS: BE screening using two additional novel findings to diagnose EMDs could be useful in general practice.

Efficacy of peroral endoscopic myotomy for esophageal motility disorders after gastric surgery: Japan Achalasia Multicenter Study.

OBJECTIVES: Patients with esophageal motility disorders (EMDs) including achalasia after gastric surgery have not been thoroughly characterized. Furthermore, the efficacy of peroral endoscopic myotomy (POEM) in this population should be clarified. METHODS: In this retrospective multicenter study of 3707 patients with EMDs, 31 patients (0.8%) had a history of gastric surgery. Patient characteristics and POEM efficacy were compared between patients with and without previous gastric surgery. RESULTS: In patients with EMD after gastric surgery, age at EMD diagnosis was higher (72.0 years), male sex was predominant (90.3%), and the American Society of Anesthesiologists physical status score was higher (≥II, 48.4%). High-resolution manometry (HRM) findings did not reveal significant differences. In patients who underwent gastric surgery, atrophic gastritis was common (80.6%), and gastric cancer was the primary surgical indication (32.3%). Distal gastrectomy was performed in 28 patients (90.3%). POEM was effective (3.3% adverse events; 100% treatment success). The incidence rates of reflux esophagitis (RE) and symptomatic gastroesophageal reflux disease (GERD) were 60.0% and 16.7%, respectively, without significant intergroup differences, and severe RE was not observed in the long-term follow-up. Extended gastric myotomy was a risk factor for RE. CONCLUSION: Patients with gastric surgery often present severe disease manifestations; the surgical indication is mainly gastric cancer. HRM findings can be similarly used for diagnosis in patients with and without gastric surgery. POEM maintains safety and efficacy with acceptable RE and symptomatic GERD rates. To prevent RE, extended myotomy should be avoided.

Risks of refractory chest pain after peroral endoscopic myotomy in achalasia-related esophageal motility disorders: short-term results from a multicenter study in Japan.

BACKGROUND AND AIMS: The etiology of chest pain in achalasia-related esophageal motility disorders and the frequency and risk factors of persistent chest pain after peroral endoscopic myotomy (POEM) remain unclear. METHODS: A multicenter cohort study including 14 hospitals was conducted to elucidate the characteristics of patients with chest pain and the efficacy of POEM. RESULTS: Consecutive cases of achalasia-related esophageal motility disorders included 2294 (64.2%) and 1280 (35.8%) patients with and without chest pain, respectively. Among the 2107 patients with chest pain who underwent POEM, we observed complete remission in 1464 patients (69.5%) and nonremission in 643 patients (30.5%), including a partial response in 619 patients (29.4%) and resistance in 24 patients (1.1%). Multivariate analysis revealed that advanced age (odds ratio [OR], .28), male sex (OR, .70), prior treatment (OR, 1.39), and sigmoid type (OR, .65) were related to the prevalence of chest pain. Long disease duration (OR, .69) and esophageal dilation (OR, .79) were related to decreased severity. POEM improved patients' quality of life that was hindered by chest pain. Early onset (OR, 1.45), advanced age (OR, .58), male sex (OR, .79), prior treatment (OR, 1.37), and posterior myotomy (OR, 1.42) were associated with nonremission after POEM; high-resolution manometry (HRM) findings and myotomy length showed no statistical significance on pain etiology and persistence after POEM. CONCLUSIONS: The prevalence and severity of chest pain were dependent on age, sex, disease duration, prior treatment, and esophageal morphology rather than HRM findings. The efficacy of POEM is satisfactory; however, residual pain was often observed. Excessively long myotomy can be avoided, and anterior myotomy may be recommended.

Development of Dilated Esophagus, Sigmoid Esophagus, and Esophageal Diverticulum in Patients With Achalasia: Japan Achalasia Multicenter Study.

Background/Aims: Patients with achalasia-related esophageal motility disorders (AEMDs) frequently present with dilated and sigmoid esophagus, and develop esophageal diverticulum (ED), although the prevalence and patients characteristics require further elucidation. Methods: We conducted a multicenter cohort study of 3707 patients with AEMDs from 14 facilities in Japan. Esophagography on 3682 patients were analyzed. Results: Straight (n = 2798), sigmoid (n = 684), and advanced sigmoid esophagus (n = 200) were diagnosed. Multivariate analysis revealed that long disease duration, advanced age, obesity, and type I achalasia correlate positively, whereas severe symptoms and integrated relaxation pressure correlate negatively with development of sigmoid esophagus. In contrast, Grade II dilation (3.5-6.0 cm) was the most common (52.9%), while grade III dilation (≥ 6 cm) was rare (5.0%). We found early onset, male, obesity, and type I achalasia correlated positively, while advanced age correlated negatively with esophageal dilation. Dilated and sigmoid esophagus were found mostly in types I and II achalasia, but typically not found in spastic disorders. The prevalence of ED was low (n = 63, 1.7%), and non-dilated esophagus and advanced age correlated with ED development. Patients with right-sided ED (n = 35) had a long disease duration (P = 0.005) with low integrated relaxation pressure values (P = 0.008) compared with patients with left-sided ED (n = 22). Patients with multiple EDs (n = 6) had lower symptom severity than patients with a single ED (P = 0.022). Conclusions: The etiologies of dilated esophagus, sigmoid esophagus, and ED are considered multifactorial and different. Early diagnosis and optimal treatment of AEMDs are necessary to prevent these conditions.

Comparisons of outcomes between ProKnife injection endoscopic submucosal dissection and conventional endoscopic submucosal dissection for large gastric lesions in ex vivo porcine model study: A randomized controlled trial.

Objective: To compare treatment outcomes between injection endoscopic submucosal dissection using ProKnife (P-ESD) and conventional ESD (C-ESD) for gastric lesions. Methods: In this randomized controlled trial, we compared treatment outcomes of P-ESD and C-ESD for simulated gastric lesions ≥3 cm in resected porcine stomachs. Predictive factors associated with ESD difficulties were investigated using logistic regression analysis. Results: Seventy lesions were screened; however, two lesions were excluded. A total of 12 endoscopists performed 68 ESDs: 34 P-ESDs and 34 C-ESDs. The ESD procedure time of P-ESD (36.3 [28.4-46.8] min) was significantly shorter than that of C-ESD (46 [36.4-64.6] min; p = 0.0014). The technical success rates did not differ between the P-ESD and C-ESD groups (en bloc resection rate, 100% in both groups; complete resection rate, 94.1% and 85.3%, respectively; p = 0.23). The number of injections during P-ESD (7.5 [6-10] times) was significantly higher than during C-ESD (4 [3-5] times; p < 0.001), but the total volume of injected solution during P-ESD (20 [16-26.3] ml) was significantly smaller than during C-ESD (27.5 [20-31.5] ml; p = 0.0019). In multivariate analysis, less ESD experience (odds ratio [OR], 3.9) and selection of C-ESD as the ESD method (OR, 3.8) were independent predictive factors associated with ESD difficulties. Conclusions: Compared with C-ESD, P-ESD had a shorter procedure time but also allowed for notable technical success and safety.

Risk factors and long-term course of gastroesophageal reflux disease after peroral endoscopic myotomy: A large-scale multicenter cohort study in Japan.

BACKGROUND : Gastroesophageal reflux disease (GERD) and reflux esophagitis remain problems after peroral endoscopic myotomy (POEM). This study aimed to elucidate the risk factors and long-term course of reflux esophagitis and symptomatic GERD after POEM. METHODS : This multicenter cohort study involved 14 high volume centers. Overall, 2905 patients with achalasia-related esophageal motility disorders treated with POEM were analyzed for reflux esophagitis, severe reflux esophagitis (Los Angeles classification C or D), and symptomatic GERD. RESULTS : Reflux esophagitis was diagnosed in 1886 patients (64.9 %). Age ≥ 65 years (risk ratio [RR] 0.85), male sex (RR 1.11), posterior myotomy (RR 1.12), esophageal myotomy > 10 cm (RR 1.12), and gastric myotomy > 2 cm (RR 1.17) were independently associated with reflux esophagitis. Severe reflux esophagitis was diagnosed in 219 patients (7.5 %). Age ≥ 65 years (RR 1.72), previous treatments (RR 2.21), Eckardt score ≥ 7 (RR 0.68), sigmoid-type achalasia (RR 1.40), and esophageal myotomy > 10 cm (RR 1.59) were factors associated with severe reflux esophagitis. Proton pump inhibitors (PPIs) were more effective for reflux esophagitis at 5-year follow-up (P = 0.03) than after 1 year (P = 0.08). Symptomatic GERD was present in 458 patients (15.9 %). Symptom duration ≥ 10 years (RR 1.28), achalasia diagnosis (RR 0.68), integrated relaxation pressure ≥ 26 (RR 0.60), and posterior myotomy (RR 0.80) were associated with symptomatic GERD. The incidence of symptomatic GERD was lower at 5-year follow-up compared with that after 1 year (P = 0.04), particularly in PPI users (P < 0.001). CONCLUSIONS : The incidence of severe reflux esophagitis was low after POEM, but excessive myotomy for older patients with previous treatments should be avoided. Early phase symptomatic GERD is non-acid reflux dependent and the natural course is favorable, basically supporting conservative treatment.

Is a small-caliber or large-caliber endoscope more suitable for colonic self-expandable metallic stent placement? A randomized controlled study.

OBJECTIVES: The colonic self-expandable metallic stent (C-SEMS) with a 9-French (Fr) delivery system allows for a small-caliber endoscope (SCE) to be used to treat malignant colonic obstruction. Despite the lack of evidence, the SCE has become popular because it is considered easier to insert than the large-caliber endoscope (LCE). We aimed to determine whether the SCE is more suitable than the LCE for C-SEMS placement. METHODS: Between July 2018 and November 2019, 50 consecutive patients who were scheduled to undergo C-SEMS for colon obstruction were recruited in this study. Patients were randomized to the SCE or LCE group. The SCE and LCE were used with 9-Fr and 10-Fr delivery systems, respectively. The primary outcome was the total procedure time. Secondary outcomes were the technical success rate, complication rate, clinical success rate, insertion time, guidewire-passage time, stent-deployment time, and colonic obstruction-scoring-system score. RESULTS: Forty-five patients (SCE group, n = 22; LCE group, n = 23) were analyzed. The procedure time in the LCE group (median, 20.5 min) was significantly (p = 0.024) shorter than that in the SCE group (median, 25.1 min). The insertion time in the LCE group (median, 2.0 min) was significantly (p = 0.0049) shorter than that in the SCE group (median, 6.0 min). A sub-analysis of the procedure difficulties showed that the insertion time in the LCE group (median, 5.0 min) was significantly shorter than that in the SCE group (median, 8.5 min). CONCLUSION: Both LCE and SCE can be used for C-SEMS; however, LCE is more suitable than SCE as it achieved a faster and equally efficacious C-SEMS placement as that of SCE. CLINICAL TRIAL REGISTRATION NUMBER: University Hospital Medical Information Network Clinical Trials Registry (UMIN 32748).