Outcomes of endoscopic submucosal dissection for esophageal cancer with segmental absence of intestinal musculature.

BACKGROUND AND AIMS: Perforation during esophageal endoscopic submucosal dissection (ESD) typically results from electrical damage. However, there are cases in which perforation occurs because of segmental absence of intestinal musculature (SAIM) without iatrogenic muscular injury. We investigated the occurrence rate and clinical course of SAIM during esophageal ESD. METHODS: We conducted a retrospective review of esophageal ESDs performed between 2013 and 2019 at 10 centers in Japan. RESULTS: Five of 1708 (0.29%) patients received ESD for esophageal cancer and had SAIM. The median muscular defect size was 20 mm. All lesions were resected without discontinuation. After resection, 3 patients were closed with Endoloop. Four patients had mediastinal emphysema. All patients were managed conservatively. CONCLUSIONS: SAIM is a very rare condition that is usually only diagnosed during ESD. Physicians performing esophageal ESD should be aware of SAIM. When SAIM is detected, the ESD technique should be modified to prevent full-thickness perforation.

Efficacy and safety of same-day preparation with sodium picosulfate plus magnesium citrate on the day of colonoscopy for bowel preparation: Multicenter, single-arm, open-label study.

BACKGROUND AND AIM: Sodium picosulfate plus magnesium citrate (SP + MC) is a well-tolerated bowel preparation agent. However, Japan currently approves only two methods of taking SP + MC: the day-before and split-dose preparation, without approval of same-day preparations. This study aimed to evaluate the efficacy and safety of same-day SP + MC preparations. METHODS: This was a multicenter, single-arm, nonrandomized, open-label study. We enrolled 145 Japanese patients between June and December 2023. The patients received two sachets of SP + MC dissolved in 300 ml of water and 1200 mL or more of clear liquid on the day of colonoscopy. Bowel cleansing efficacy, adverse events (AEs), and patient satisfaction were evaluated. RESULTS: Of the enrolled patients, 137 underwent colonoscopy according to our protocol. Bowel preparation was adequate in 133 patients (97.1%). The mean total Boston Bowel Preparation Score was 8.3 ± 1.2. Five patients experienced AEs (3.6%): two (1.5%), abdominal pain; one (0.73%), ischemic enteritis; one (0.73%), vomiting or nausea; and one (0.73%), headache. All AEs were treated conservatively. None of the patients exhibited abnormal blood test results or clinical symptoms after receiving SP + MC. Regarding patient satisfaction, all patients were able to take SP + MC as directed; 136 (99.2%) expressed a preference for this bowel preparation for future colonoscopies. CONCLUSION: The same-day SP + MC preparation showed high bowel-cleansing efficacy and satisfaction in Japanese patients without serious AEs.

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.

Long-Term Outcomes of Endoscopic Submucosal Dissection for Early Remnant Gastric Cancer: A Retrospective Multicenter Study.

INTRODUCTION: Favorable long-term outcomes of endoscopic submucosal dissection (ESD) for early remnant gastric cancer (ERGC) have been reported in single-center studies from advanced institutions. However, no studies have examined the long-term outcomes using a multicenter database. This study aimed to investigate the long-term outcomes of the aforementioned approach using a large multicenter database. METHODS: This retrospective multicenter cohort study included 242 cases with 256 lesions that underwent ESD for ERGC between April 2009 and March 2019 across 12 centers. We investigated the long-term outcomes of these patients with the Kaplan-Meier method, and the relationship between curability, additional treatment, or hospital category, and the survival time was evaluated using the log-rank test. RESULTS: During the median follow-up period of 48.4 months, the 5-year overall survival rate was 81.3%, and the 5-year gastric cancer-specific survival rate was 98.1%. The survival time of patients of endoscopic curability (eCura) C-2 without additional surgery was significantly shorter than the corresponding of patients of eCura A/B/C-1 and eCura C-2 with additional surgery. There was no significant difference in either overall survival or gastric cancer-specific survival rate between the high-volume and non-high-volume hospitals. CONCLUSION: The gastric cancer-specific survival of ESD for ERGC using a multicenter database was favorable. ESD for ERGC is widely applicable regardless of the hospital case volume. Management in accordance with the latest guidelines will lead to long-term survival.

Characteristics of Gastric Stasis due to Deformation after Endoscopic Submucosal Dissection in the Lower Part of the Stomach.

INTRODUCTION: Gastric stasis due to deformation occurs after endoscopic submucosal dissection in the lower part of the stomach. Endoscopic balloon dilation can improve gastric stasis due to stenosis; however, endoscopic balloon dilation cannot improve gastric stasis due to deformation. Furthermore, the characteristics of gastric stasis due to deformation are unknown. This study aimed to evaluate the characteristics of gastric stasis due to deformation after endoscopic submucosal dissection in the lower part of the stomach, focusing on the differences between stenosis and deformation. METHODS: We retrospectively reviewed 41 patients with gastric stasis after endoscopic submucosal dissection in the lower part of the stomach. We evaluated the characteristics of cases with gastric stasis due to deformation, such as the risk factors of deformation and the rate of deformation in each group with risk factors. RESULTS: Deformation was observed in 12% (5/41) of the patients with gastric stasis. All cases of deformation had a circumferential extent of the mucosal defect greater than 3/4. The number of cases with pyloric dissection was significantly lower in the deformation group than in the non-deformation group (0% vs. 72%; p = 0.004). The deformation group also had a significantly higher number of cases with angular dissection than the non-deformation group (100% vs. 17%; p < 0.001). Moreover, the deformation cases had a significantly larger specimen diameter (p < 0.001). Deformation was observed only in cases with angular and non-pyloric dissections. Deformation was not observed in cases with angular and pyloric dissections. CONCLUSIONS: All cases of gastric stasis due to deformation had a circumferential extent of the mucosal defect greater than 3/4. Deformation was also likely to occur in cases with a larger dissection that exceeded the angular region without pyloric dissection.

Risk-scoring system for predicting challenging cases of peroral endoscopic myotomy.

OBJECTIVES: Peroral endoscopic myotomy (POEM) is an effective treatment for esophageal motility disorders including achalasia and its variants. However, some surgeons have encountered challenging cases. This study aimed to develop a risk-scoring system to predict challenging cases of POEM. METHODS: Consecutive patients who underwent POEM between April 2015 and March 2020 at our hospital were included in this single-center retrospective study. Challenging cases of POEM were defined as patients with any of the following: (i) procedure time ≥90 min; (ii) mucosal perforation; (iii) pneumothorax; and (iv) major bleeding. A risk-scoring system for predicting challenging cases was developed based on multivariate logistic regression and internal validation was performed using the bootstrap method. Clinical usefulness was evaluated using a decision curve analysis. RESULTS: Of the 467 patients, 59 (12.6%) had challenging POEM. A risk-scoring system consisted of four variables: duration of symptoms ≥5 years (assigned score, 1 point), antithrombotics use (1 point), manometric diagnosis of achalasia variants (2 points), and dilation grade 3 (2 points). Our scoring system showed satisfactory discrimination (area under the receiver operating characteristic curve, 0.69; 95% confidence interval [CI] 0.61-0.77) and calibration (slope, 0.99; 95% CI 0.65-1.35). The decision curve analysis demonstrated its clinical usefulness. CONCLUSIONS: We established a risk-scoring system to predict challenging cases of POEM. This scoring system may aid the selection of patients who require treatment from experienced surgeons.

Assessment of predictive factors associated with the technical difficulty of endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma: Japanese multicenter retrospective study.

OBJECTIVES: Endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell carcinoma (ESCC) is performed for the treatment of lesions with varied backgrounds and factors. However, the predictive factors associated with the technical difficulty of ESD remain unknown in patients with varied lesions. Therefore, this study aimed to identify the predictive factors associated with the technical difficulty of ESD for ESCC using a retrospective cohort. METHODS: This multicenter, retrospective study was conducted in 10 hospitals in Japan. Consecutive patients who underwent esophageal ESD between January 2013 and December 2019 were enrolled. Lesions of subepithelial tumors, adenocarcinoma, and adenoma were excluded. Difficult lesions were defined as ESD requiring a long procedure time (≥120 min), perforation development, piecemeal resection, or discontinued ESD. In the present study, the clinical factors were assessed to identify the technical difficulty of ESD using univariate and multivariate analyses. RESULTS: Among 1708 lesions treated with esophageal ESD, eight subepithelial tumors, 44 adenocarcinomas, and two adenomas were excluded. Finally, 1505 patients with 1654 lesions were analyzed, and 217 patients with 217 lesions (13.1%) were classified as patients with difficult lesions. In multivariate analysis, the predictive factors associated with the technical difficulty of ESD were as follows: tumors with varices, tumors with diverticulum, antiplatelet use (discontinued), circumference of tumor (≥1/2), preoperative tumor size ≥30 mm, trainee, and nonhigh-volume center. CONCLUSION: This multicenter retrospective study identified the predictive factors associated with the technical difficulty of ESD for ESCC with varied backgrounds and factors.

Safety and efficacy of endoscopic submucosal dissection for superficial esophageal cancer with esophageal varices.

BACKGROUND: Heavy drinking is associated with esophageal cancer and esophageal varices. However, there are limited reports of endoscopic resection for esophageal cancer with esophageal varices. In this multicenter study, we clarified the safety and efficacy of endoscopic submucosal dissection for superficial esophageal cancer with esophageal varices. METHODS: In this multicenter, retrospective, observational study, patients underwent esophageal endoscopic submucosal dissection at 10 referral centers in Japan from January 2013 to December 2019. We analyzed characteristics including backgrounds and varices, treatment outcomes, and adverse events in cases with esophageal varices. RESULTS: A total of 1708 patients were evaluated, 27 (1.6%) of whom had esophageal varices. In patients with esophageal varices, the en bloc resection rate and R0 resection rate were 100% and 77.8%, respectively. Patients with esophageal varices had longer procedure times than patients without esophageal varices (p = 0.015). There was no significant difference in adverse events. There was no significant difference in procedure time and number of adverse events between patients who underwent pretreatment and those who did not. There was no significant difference in these outcomes for patients with lesions on varices compared to those without. Child-Pugh classification and location of the lesions also did not affect these outcomes. CONCLUSIONS: Esophageal cancer with esophageal varices could be treated endoscopically safely and effectively.

Per-oral endoscopic myotomy in patients with antithrombotic agents: A large-scale multicenter study in Japan.

BACKGROUND AND AIM: The perioperative management and clinical course of per-oral endoscopic myotomy for patients receiving antithrombotic therapy remains unknown. This study aimed to clarify the status of antithrombotic therapy in per-oral endoscopic myotomy and to determine its safety and efficacy. METHODS: Patients treated with per-oral endoscopic myotomy from 2010 to 2019 in seven high-volume centers in Japan were retrospectively investigated. The patients' characteristics and antithrombotic agent management were analyzed; clinical outcomes were compared with those without antithrombotic agents. RESULTS: Of 2752 patients who underwent per-oral endoscopic myotomy, 120 patients on antithrombotic therapy (mean age 71.0 years, American Society of Anesthesiologists class II-IV [67.5%]) were identified. Antiplatelet, anticoagulant, and a combination of antithrombotic agents were used in 82, 30, and 8 patients, respectively. The perioperative management adhered to the therapeutic endoscopy guidelines published by the Japanese Society of Gastroenterological Endoscopy in most patients (88.3%). A poorer clinical baseline status (American Society of Anesthesiologists class II-IV; 67.0% vs 24.3%) and the sigmoid type (40.7% vs 22.3%) were more frequently observed in patients with achalasia on antithrombotic therapy. However, the clinical success (Eckardt score ≤ 3; 97.6% vs 94.6) and adverse event rates, such as bleeding and thromboembolic events (5.5% vs 4.7%), did not show inferiority. CONCLUSIONS: Per-oral endoscopic myotomy on antithrombotic therapy is safe and effective. However, caution is required as patients on antithrombotic therapy tend to have poorer baseline health and achalasia statuses. Our experience should help establish perioperative management with antithrombotic therapy.

Predicting Inadequate Bowel Preparation When Using Sodium Picosulfate plus Magnesium Citrate for Colonoscopy: Development and Validation of a Prediction Score.

INTRODUCTION: Sodium picosulfate plus magnesium citrate is a bowel preparation agent with high patient acceptability. However, it is unclear which patients are more likely to have inadequate bowel preparation when using this agent. This study aimed to identify the risk factors for inadequate bowel preparation when using sodium picosulfate plus magnesium citrate for colonoscopy and to develop a scoring model to predict which patients will have inadequate bowel preparation. METHODS: A total of 350 Japanese patients were enrolled from June 2021 to April 2022. Data on patient background, details of colonoscopy, and satisfaction assessment questionnaire results were prospectively collected. The scoring model for inadequate bowel preparation was developed based on multiple logistic regression analyses, and its performance was internally validated using bootstrapping. RESULTS: Adequate bowel preparation was obtained in 295 patients (84.3%); 335 (95.7%) were able to ingest the drug without difficulty. The scoring model consisted of five independent risk factors and points of risk scores were assigned to each one as follows: American Society of Anesthesiologists physical status III (1 point), diabetes comorbidities (5 points), use of laxatives (4 points), no defecation once in a day (2 points), and drug use for mental disorder (6 points). The C-statistics of the scoring system for inadequate bowel preparation was 0.75. DISCUSSION: We identified five risk factors for inadequate bowel preparation when using sodium picosulfate plus magnesium citrate regimen and developed a scoring model for inadequate bowel preparation with satisfactory discrimination and calibration.

The risk scoring system for assessing the technical difficulty of endoscopic submucosal dissection in cases of remnant gastric cancer after distal gastrectomy.

BACKGROUND: Endoscopic submucosal dissection (ESD) for remnant gastric cancer (RGC) after distal gastrectomy (DG) is considered technically challenging due to the narrow working space, and severe fibrosis and staples from the previous surgery. Technical difficulties of ESD for RGC after DG have not been thoroughly investigated. This study aimed to develop and validate a risk-scoring system for assessing the technical difficulty of ESD for RGC after DG in a large multicenter cohort. METHODS: We investigated patients who underwent ESD for RGC after DG in 10 institutions between April 2008 and March 2018. A difficult case was defined as ESD lasting ≥ 120 min, involving piecemeal resection, or the occurrence of perforation during the procedure. A risk-scoring system for the technical difficulty of the procedure was developed based on multiple logistic regression analyses, and its performance was internally validated using bootstrapping. RESULTS: A total of 197 consecutive patients with 201 lesions were analyzed. There were 90 and 111 difficult and non-difficult cases, respectively. The scoring model consisted of four independent risk factors and points of risk scores were assigned for each as follows: tumor size > 20 mm: 2 points; anastomosis site: 2 points; suture line: 1 point; and non-expert endoscopist: 2 points. The C-statistics of the scoring system for technical difficulty was 0.72. CONCLUSIONS: We developed a validated risk-scoring model for predicting the technical difficulty of ESD for RGC after DG that can contribute to its safer and more reliable performance.

Geriatric patients with esophageal motility disorders benefit more from minimally invasive peroral endoscopic myotomy: a multicenter study in Japan.

Geriatric patients with existing studies on the safety and efficacy of peroral endoscopic myotomy (POEM) for achalasia involve small sample sizes and single institutions. However, multi-center, large-scale data analyses are lacking. The study aimed to clarify the characteristics of geriatric patients with esophageal motility disorders (EMDs) and determine the procedure-related outcomes and clinical course following POEM. This cohort study included 2,735 patients with EMDs who were treated at seven Japanese facilities between 2010 and 2019. The patients' characteristics and post-POEM clinical courses were compared between the geriatric (age ≥ 75 years; n = 321) and non-geriatric (age < 75 years; n = 2,414) groups. Compared with the non-geriatric group, the geriatric group had higher American Society of Anesthesiologists physical status scores; more recurrent cases; lower incidence of chest pain; and higher incidence of type III achalasia, distal esophageal spasm, and Jackhammer esophagus. Furthermore, the incidence of sigmoid esophagus was higher, although esophageal dilation was not severe in this group. POEM was safe and effective for geriatric patients with treatment-naïve and recurrent EMDs. Furthermore, compared with the non-geriatric group, the geriatric group had lower post-POEM Eckardt scores, fewer complaints of refractory chest pain, and a lower incidence rate of post-POEM reflux esophagitis. Geriatric patients are characterized by worse clinical conditions, more spastic disorders, and greater disease progression of EMDs, which are also the indications for minimally invasive POEM. POEM is more beneficial in geriatric patients as it has lowering symptom scores and incidence rates of reflux esophagitis.

Esophageal motility disorders missed during endoscopy.

BACKGROUND: Esophageal motility disorders are sometimes misdiagnosed on endoscopic examination. We aimed to identify the proportion of patients with esophageal motility disorders missed during endoscopy and their clinical characteristics. METHODS: Patients diagnosed with either disorder with esophagogastric junction outflow obstruction or major disorders of peristalsis using high-resolution manometry in our hospital from April 2015 to March 2021 were included in this study. Missed esophageal motility disorders were defined as patients with any endoscopic misdiagnosis such as normal esophagus or esophagitis within 1 year before the manometric diagnosis. We determined the proportion of missed esophageal motility disorders and identified independent predictors of missed esophageal motility disorders using multivariate analysis. RESULTS: A total of 41/273 esophageal motility disorders (15.0%; 95% confidence interval 11.3-19.7%) were missed during endoscopy within 1 year before manometric diagnosis. In the stepwise logistic regression analysis, the following variables were selected as independent variables for patients with missed esophageal motility disorders during endoscopy: non-dilated esophagus (odds ratio = 4.87, 95% confidence interval: 1.81-13.12, p = 0.002), the presence of epiphrenic diverticulum (odds ratio = 8.95, 95% confidence interval: 1.88-42.65, p = 0.006), the use of transnasal endoscopy (odds ratio = 4.71, 95% confidence interval: 1.59-13.92, p = 0.005), and the combined use of esophagram (odds ratio = 0.023, 95% confidence interval: 0.0025-0.20, p = 0.0008). CONCLUSIONS: Based on retrospective analysis, 15% of esophageal motility disorders were missed during endoscopy. Understanding the clinical characteristics of missed esophageal motility disorders could help improve endoscopic diagnoses.

Characteristics of patients with esophageal motility disorders on high-resolution manometry and esophagography-a large database analysis in Japan.

BACKGROUND: With the development of high-resolution manometry (HRM) and peroral endoscopy, more patients with esophageal motility disorders (EMDs) including achalasia are diagnosed and treated. The characteristics of Japanese patients with EMDs are unknown and should be elucidated. METHODS: A large-scale database analysis was performed at seven high-volume centers in Japan. EMDs between 2010 and 2019 were analyzed. RESULTS: A total of 1900 patients were diagnosed with treatment naïve achalasia on esophagography. A long disease history was related to the sigmoid and dilated esophagus, and patients' symptom severity declined as achalasia progressed to the sigmoid type. Among 1700 patients received starlet HRM, 1476 (86.8%) completed the examination. Long disease history and sigmoid achalasia were identified as risk factors for the failure of HRM examination. Type I achalasia was the most common type found on starlet HRM, and 45.1% of patients with achalasia had lower esophageal sphincter (LES) pressure within the normal range. Type III had a high age of onset and mild symptom severity, compared to the other two subtypes. Type III achalasia, esophagogastric outflow obstruction (EGJ-OO), jackhammer esophagus (JE), and diffuse esophageal spasm (DES) were relatively rare compared to type I-II achalasia. The clinical characteristics of EGJ-OO, JE, and DES were generally close to those of achalasia. CONCLUSION: This first large-scale database analysis indicates that more Japanese patients with achalasia are type I and have a normal range of LES pressure on starlet HRM. Failure of HRM is not rare; therefore, esophagography continuously has a complementary role in achalasia diagnosis.

Pivotal trial of a biodegradable stent for patients with refractory benign esophageal stricture.

OBJECTIVE: Benign esophageal strictures (BES) cause dysphagia and decrease patients' quality of life. Although mechanical dilation is the standard of care for BES, in some patients, dysphagia is unrelieved despite repeated procedures. The biodegradable stent was developed to resolve refractory BES, with reported favorable outcomes, but it is unapproved in Japan. Thus, we evaluated the safety and efficacy of the biodegradable stent (BDS) for patients with refractory BES for regulatory approval. METHODS: This was a nonrandomized single-arm prospective trial conducted at eight institutions. We included patients with BES after ≥ 5 times of dilation or ≥ one time of radial incision and cutting whose dysphagia score (DS) was 2 or worse and an endoscope could not admit. The primary endpoint was the proportion of patients whose DS improvement of ≤ 1 was maintained at 3 months. RESULTS: Thirty patients (median age: 69 years, male/female: 27:3) were enrolled and treated; BDS placement failed in 1 patient. Fourteen patients maintained their DS improvement until 3 months after placement (proportion of DS improvement at 3 months 46.7% [95% CI: 28.3-65.7]), and the median dysphagia-free survival was 98 days [95% CI: 68-123]. Most adverse events could be managed conservatively; however, a patient with BES after chemoradiotherapy (CRT) developed an esophago-left atrium fistula and died approximately 4 months after stent placement. CONCLUSION: The BDS was effective for refractory BES and the safety was acceptable. However, the indication for this procedure in patients RECEIVING CRT for esophageal cancer should be carefully considered.

Development of a preoperative risk-scoring system for predicting poor responders to peroral endoscopic myotomy.

BACKGROUND AND AIMS: Peroral endoscopic myotomy (POEM) is an effective treatment for esophageal motility disorder. However, some people are poor responders who will probably need retreatments, such as endoscopic pneumatic dilation or re-POEM, and a scoring system for the prediction of poor responders preoperatively has not yet been established. We aimed to develop and validate a preoperative scoring system for predicting poor responders. METHODS: Overall, 244 patients who underwent POEM for esophageal motility disorders in our hospital from April 2015 to March 2019 were retrospectively included in this study. Poor responders were defined as patients with any of following: (1) Eckardt score ≥3 at 1-year follow-up, (2) endoscopic findings of food retention at 1-year follow-up, and (3) retreatments within 1 year after POEM. A risk-scoring system for poor responders was developed based on multiple logistic regression analysis, and its performance was internally validated using bootstrapping. RESULTS: Forty patients were diagnosed as poor responders at the 1-year follow-up. In the multivariate study, points for risk scores were assigned for 4 independent risk factors as follows: pretreatment Eckardt score (1-point increments), previous treatments (4 points), sigmoid-type esophagus (4 points), and esophageal dilation grade ≥II (4 points). The scoring system could predict an estimated risk for poor responders and provided satisfactory discrimination (area under the receiver operating characteristic curve, 0.78; 95% confidence interval, 0.68-0.88) and calibration (slope = 0.93; 95% confidence interval, 0.62-1.31). CONCLUSIONS: A validated risk-scoring system for predicting poor responders preoperatively was established; this system could be useful for selecting treatment strategies and postoperative surveillance.

Frequency and clinical characteristics of special types of achalasia in Japan: A large-scale, multicenter database study.

BACKGROUND AND AIM: Achalasia is a rare disease, with an incidence of one in 100 000. Genetic factors and autoimmune involvement have been reported in its etiology, and their involvement is strongly suspected, especially in patients with familial achalasia and those with comorbid hereditary or autoimmune diseases. However, these special types of achalasia are rare, and their frequency and clinical characteristics remain unclear. METHODS: This retrospective, multicenter cohort study included Japanese patients with a diagnosis of achalasia, treated between 2010 and 2019 across six tertiary centers in Japan. The frequency and clinical characteristics of special types of achalasia, namely, familial achalasia, achalasia with a comorbid hereditary disease, and achalasia with a comorbid autoimmune disease, were retrospectively investigated using a large-scale multicenter database. RESULTS: During the study period, 1115 patients were treated for achalasia at six tertiary centers. Familial achalasia, achalasia with a comorbid hereditary disease, and achalasia with a comorbid autoimmune disease occurred in 7 (0.63%), 11 (0.99%), and 27 (2.4%) patients, respectively. Familial achalasia had a slightly younger age of onset (37.6 ± 12.1 years old) and a higher incidence in male patients (six patients; 85.7%). Down's syndrome was the most common hereditary comorbidity, and thyroid disease was the most common autoimmune comorbidity. CONCLUSIONS: We clarified the frequency and clinical characteristics of special types of achalasia. Although special types of achalasia are rare, these comorbidities should be considered when treating patients with achalasia.

Factors associated with inaccurate size estimation of colorectal polyps: A multicenter cross-sectional study.

BACKGROUND AND AIM: Accurate polyp size estimation is essential in deciding the therapeutic strategy of colorectal polyps and endoscopic surveillance intervals. However, many endoscopists frequently make incorrect size estimations without being aware of their errors. This cross-sectional study aimed to clarify the characteristics of endoscopists associated with inaccurate estimation. METHODS: We previously conducted a web trial involving 261 endoscopists in 51 institutions in Japan to assess their ability to estimate polyp size. Participants answered questions about polyp size using visual estimates in a test involving images of 30 polyps. Here, we investigated the relationships between inaccurate size estimation and the backgrounds of participants. The rates of overestimation and underestimation of polyp size were also compared to clarify any trends in the answers of participants with low accuracy (< 50%). RESULTS: Multivariable logistic regression analysis revealed that the number of colonoscopic procedures in the past year was the only factor associated with a low accuracy of polyp size estimation (odds ratio 0.750, 95% confidence interval 0.609-0.925; P = 0.007). Endoscopists with low accuracy had a greater tendency to overestimate polyp size (42.3% overestimation and 21.2% underestimation, P < 0.001) compared with other endoscopists (16.6% overestimation and 17.9% underestimation, P = 0.951). CONCLUSIONS: Endoscopists with limited experience of colonoscopy in the past year were more likely to make frequent errors in size estimation. Furthermore, endoscopists making inaccurate size estimations had a propensity to overestimate polyp size.

Timing of pyloric stenosis and effectiveness of endoscopic balloon dilation after pyloric endoscopic submucosal dissection.

BACKGROUND AND AIM: There have been studies on risk factors for stenosis after pyloric endoscopic submucosal dissection (ESD). However, the most appropriate strategies for the management of cases with these risk factors have not been established. This study aimed to investigate post-ESD management by evaluating the timing of stenosis and the effectiveness of endoscopic balloon dilation (EBD) after pyloric ESD. METHODS: We retrospectively reviewed cases of pyloric ESD. We first reassessed risk factors for stenosis in multivariate analysis and receiver operating characteristic curve and defined patients with the identified risk factors as the risk group. The primary outcome was the timing of stenosis in the risk group assessed by the Kaplan-Meier method. RESULTS: We reviewed 159 cases with pyloric ESD and observed pyloric stenosis in 25 cases. Cases with circumferential mucosal defect ≥ 76% were identified as the risk group. The stenosis-free probability in the risk group was 97% (95% confidence interval [CI]: 79-100%), 94% (95% CI: 76-98%), and 85% (95% CI: 66-93%) on days 7, 14, and 21, respectively. It decreased every week thereafter and did not significantly change after day 56. Twenty-three stenosis cases, except for conservative improvement, including six whole circumferential pyloric ESD cases, were improved by EBD without complications. CONCLUSIONS: Post-ESD stenosis often developed from the third to the eighth week. In all pyloric ESD cases, including whole circumferential pyloric ESD cases, pyloric stenosis was improved following EBD without complications.

Feasibility and Safety of Endoscopic Submucosal Dissection for Recurrent Rectal Lesions that after Transanal Endoscopic Microsurgery: A Case Series.

OBJECTIVES: Recently, several studies have demonstrated the usefulness of endoscopic submucosal dissection (ESD) for residual or locally recurrent colorectal lesions after endoscopic treatment. However, the feasibility of ESD for recurrent rectal lesions after transanal endoscopic microsurgery (TEM) has not been fully investigated. In this study, we evaluated the feasibility and safety of ESD for recurrent rectal lesions after TEM. METHODS: The treatment outcomes of 10 lesions in 9 patients, who underwent ESD between January 2006 and March 2018 for recurrent rectal lesions after transanal endoscopic microsurgery, were evaluated. RESULTS: All lesions were successfully resected en bloc, and the R0 resection rate was 90%. The median size of the resected specimens and lesions (range) was 44 mm (21-70) and 27.5 mm (5-60), respectively. The pathological diagnoses included 4 adenomas and 6 cancerous lesions. The cancerous lesions included 5 cases of mucosal cancer and 1 case of superficial submucosal invasive cancer (depth of submucosal invasion <1,000 µm from the muscularis mucosae). No adverse events occurred. There was no recurrence during the follow-up period. CONCLUSIONS: ESD for recurrent rectal lesions after TEM by expert's hands appears to be safe and feasible.