A scoring system to predict the technical difficulty of endoscopic resection for cardial submucosal tumors.

BACKGROUND AND AIM: Endoscopic resection has been successfully used for the removal of digestive submucosal tumors (SMTs). However, the cardia has been considered a challenging location for endoscopic resection due to its narrow lumen and sharp angle. The objective of this study was to establish a clinical scoring model to grade the technical difficulty of endoscopic resection for cardial SMTs. METHODS: A total of 246 patients who suffered cardial SMTs and received endoscopic resection were included in this retrospective study. All of them were randomized into the training cohort (n = 123) or internal validation cohort (n = 123). Potential predictors were analyzed using univariate analysis. Then, covariates with P < 0.05 were selected for the multivariate logistic regression model. The ß coefficients from the logistic regression model were used to create a scoring system for technical difficulty prediction by rounding the score to the nearest integer of the absolute ß coefficient value. RESULTS: The clinical score consisted of the following factors: male gender (2 points), extraluminal growth (3 points), and maximum diameter ≥3 cm (3 points). The scoring model demonstrated good discriminatory power, with an area under the receiver operating characteristic curve of 0.860 and a 95% confidence interval of 0.763-0.958. The model also showed a good goodness of fit in the Hosmer-Lemeshow test (P = 0.979). In the training cohort, the probability of encountering technical difficulty in the easy (score = 0), intermediate (score = 1-3), difficult (score = 4-6), and very difficult (score >6) categories was 0, 6.8%, 33.3%, and 100.0%, respectively; similarly, in the validation cohort, it was 0, 5.6%, 22.2%, and 50.0%, respectively. CONCLUSIONS: This scoring system could serve as a valuable tool for clinicians in predicting the technical difficulty of endoscopic resection for cardial SMTs.

Endoscopic resection for calcifying fibrous tumors of the gastrointestinal tract.

BACKGROUND: Calcifying fibrous tumors (CFTs) are rare mesenchymal lesions that can occur in various sites throughout the body, including the tubular gastrointestinal (GI) tract. AIM: To analyze the clinical findings of 36 patients with GI tract CFTs to provide guidance for diagnosis and treatment. METHODS: This retrospective study included 36 patients diagnosed with CFTs of the GI tract. We collected demographic and clinical information and conducted regular follow-ups to assess for local recurrence. RESULTS: The stomach was the most commonly involved site, accounting for 72.2% of the 36 CFTs. Endoscopic mucosal resection (n = 1, 2.8%), endoscopic submucosal dissection (n = 14, 38.9%), endoscopic full-thickness resection (n = 16, 44.4%), and submucosal tunneling endoscopic resection (n = 5, 13.9%) were used to resect calcifying fibrous tumors. Overall, 34 (94.4%) CFTs underwent complete endoscopic resections with a mean procedure time of 39.8 ± 29.8 min. The average maximum diameter of the tumors was 10.6 ± 4.3 cm. No complications, such as bleeding or perforation, occurred during an average hospital stay of 2.9 ± 1.2 d. In addition, two patients developed new growth of CFTs near the primary tumor sites, and none of the patients developed distant metastases during the follow-up period. CONCLUSION: GI tract CFTs are rare and typically benign tumors that can be effectively managed with endoscopic procedures.

Long-term outcomes of endoscopic resection for well-differentiated nonampullary duodenal neuroendocrine tumors.

BACKGROUND & AIMS: Nonampullary duodenal neuroendocrine tumors (NAD-NETs) are rare with limited evidence regarding endoscopic treatment. The study aimed to investigate the efficacy and safety of endoscopic resection of well-differentiated NAD-NETs and evaluate long-term outcomes, including local recurrence and metastasis. METHODS: A total of 78 patients with NAD-NETs who underwent endoscopic resection between January 2011 and August 2022 were included. The clinicopathologic characteristics and treatment outcomes were collected and analyzed. RESULTS: En bloc resection was achieved for 74 of the tumors (94.9%) and R0 resection was obtained in 68 of the tumors (87.2%). Univariate analysis identified tumors in the second part of the duodenum, tumor size ≥ 10 mm and muscularis propria invasion as risk factors for non-curative resection. Two patients with R1 resection (vertical margin involvement) and two patients with lymphovascular invasion underwent additional surgery. Four patients experienced adverse events (5.1%), including two cases of delayed bleeding and two cases of perforation, all successfully managed conservatively. During a median follow-up period of 62.6 months, recurrence and lymph node metastasis were only detected in one patient with R1 resection 3 months after the original procedure. CONCLUSION: Endoscopic resection is safe and effective and provides a favorable long-term outcome for patients with well-differentiated NAD-NETs without regional lymph node or distant metastasis.

Endoscopic features and treatments of gastric cystica profunda.

BACKGROUND: Gastric cystica profunda (GCP) represents a rare condition characterized by cystic dilation of gastric glands within the mucosal and/or submucosal layers. GCP is often linked to, or may progress into, early gastric cancer (EGC). AIM: To provide a comprehensive evaluation of the endoscopic features of GCP while assessing the efficacy of endoscopic treatment, thereby offering guidance for diagnosis and treatment. METHODS: This retrospective study involved 104 patients with GCP who underwent endoscopic resection. Alongside demographic and clinical data, regular patient follow-ups were conducted to assess local recurrence. RESULTS: Among the 104 patients diagnosed with GCP who underwent endoscopic resection, 12.5% had a history of previous gastric procedures. The primary site predominantly affected was the cardia (38.5%, n = 40). GCP commonly exhibited intraluminal growth (99%), regular presentation (74.0%), and ulcerative mucosa (61.5%). The leading endoscopic feature was the mucosal lesion type (59.6%, n = 62). The average maximum diameter was 20.9 ± 15.3 mm, with mucosal involvement in 60.6% (n = 63). Procedures lasted 73.9 ± 57.5 min, achieving complete resection in 91.3% (n = 95). Recurrence (4.8%) was managed via either surgical intervention (n = 1) or through endoscopic resection (n = 4). Final pathology confirmed that 59.6% of GCP cases were associated with EGC. Univariate analysis indicated that elderly males were more susceptible to GCP associated with EGC. Conversely, multivariate analysis identified lesion morphology and endoscopic features as significant risk factors. Survival analysis demonstrated no statistically significant difference in recurrence between GCP with and without EGC (P = 0.72). CONCLUSION: The findings suggested that endoscopic resection might serve as an effective and minimally invasive treatment for GCP with or without EGC.

Endoscopic resection of giant esophageal subepithelial lesions: experience from a large tertiary center.

BACKGROUND AND AIMS: Increased reports on endoscopic resection (ER) of esophageal giant subepithelial lesions (g-SELs) have emerged in recent years. The aim of this study was to evaluate the efficacy, technical difficulty, and safety through our single-center experience. METHODS: Seventy-five patients with g-SELs undergoing endoscopic resection were included in the training set. Clinicopathologic features, procedure-related characteristics, postprocedural outcomes, and follow-up data were analyzed. A predictive nomogram model for procedural difficulty was proposed based on the multivariable logistic regression analysis. Internal and external validations were conducted to verify the model performance. RESULTS: The overall en bloc resection rate was 93.3%. Intraoperative and postoperative adverse events occurred in 7 (9.3%) and 13 (17.3%) patients, respectively. No recurrence or metastasis was observed. Thirty-two (42.7%) patients underwent a difficult procedure. Age (adjusted odds ratio [aOR], .915; P = .004), maximal tumor diameter ≥8 cm (aOR, 9.896; P = .009), irregular shape (aOR, 4.081; P = .053), extraluminal growth pattern (aOR, 5.419; P = .011), and submucosal tunneling endoscopic resection (aOR, .109; P = .042) were found to be statistically or clinically significant factors for predicting endoscopic resection difficulty, based on which a nomogram model was developed. Internal and external validations of the nomogram via receiver-operating characteristic curves and calibration curves achieved favorable results. CONCLUSIONS: Endoscopic resection serves as a promising therapeutic option for esophageal g-SELs. A younger patient age, large tumor size, irregular shape, and extraluminal growth may indicate increased endoscopic resection difficulty, whereas a submucosal tunneling endoscopic resection procedure tends to be of lower difficulty. Our nomogram model performs well for predicting endoscopic resection difficulty for esophageal g-SELs.

Feasibility and safety of endoscopic resection for the jejunoileal lesions.

BACKGROUND: Endoscopic resection (ER) for jejunoileal lesions (JILs) has been technically challenging. We aimed to characterize the clinicopathologic characteristics, feasibility, and safety of ER for JILs. METHOD: We retrospectively investigated 52 patients with JILs who underwent ER from January 2012 to February 2022. We collected and analyzed clinicopathological characteristics, procedure-related parameters, outcomes, and follow-up data. RESULTS: The mean age was 49.4 years. Of the 52 JILs, 33 ileal tumors within 20 cm from the ileocecal valve were resected with colonoscopy, while 19 tumors in the jejunum or the ileum over 20 cm from the ileocecal valve received enteroscopy resection. The mean procedure duration was 49.0 min. The en bloc resection and en bloc with R0 resection rates were 86.5% and 84.6%, respectively. Adverse events (AEs) included one (1.9%) major AE (delayed bleeding) and five (9.6%) minor AEs. During a median follow-up of 36.5 months, two patients had local recurrence (3.8%), while none had metastases. The 5-year recurrence-free survival (RFS) and disease-specific survival (DSS) were 92.9% and 94.1%, respectively. Compared with the enteroscopy group, overall AEs were significantly lower in the colonoscopy group (P < 0.05), but no statistical differences were observed in RFS (P = 0.412) and DSS (P = 0.579). There were no significant differences in AEs, RFS, and DSS between the endoscopic submucosal dissection (ESD) and the endoscopic mucosal resection (EMR) group. CONCLUSIONS: ER of JILs has favorable short-term and long-term outcomes. Both ESD and EMR can safely and effectively resect JILs in appropriately selected cases.

Endoscopic management of duodenal perforation caused by foreign bodies in adults: A retrospective study.

BACKGROUND AND AIMS: Duodenal perforation caused by foreign bodies (FBs) is very rare but is an urgent emergency that traditionally requires surgical intervention. Several case reports have reported the successful endoscopic removal of duodenal perforating FBs. Here we aimed to evaluate the safety and efficacy of endoscopic management of duodenal perforating FBs in adults. METHODS: Between October 2004 and October 2022, 12,851 patients with endoscopically diagnosed gastrointestinal FBs from four tertiary hospitals in China were retrospectively reviewed. Patients were enrolled if they were endoscopically and/or radiographically diagnosed with duodenal perforating FBs. RESULTS: The incidence of duodenal total FBs and perforating FBs was 1.9% and 0.3%, respectively. Thirty-four patients were enrolled. Endoscopic removal was achieved in 25 patients (73.5%), and nine patients (26.5%) received surgery. For the endoscopic group, most perforating FBs were located in the duodenal bulb (36.0%) and descending part (28.0%). The adverse events included 3 mucosal injuries and 1 localized peritonitis. All patients were cured after conventional treatment. In the surgical group, most FBs were lodged in the descending part (55.6%). One patient developed localized peritonitis and one patient died of multiple organ failure. The significant features of FBs requiring surgery included FB over 10 cm, both sides perforation, multiple perforating FBs and massive pus overflow. CONCLUSION: Endoscopic removal of duodenal perforating FBs is safe and effective, and can be the first choice of treatment for experienced endoscopists. Surgical intervention may be required for patients with FBs over 10 cm, both sides perforation, multiple perforating FBs, or severe infections.

Markov modeling and performance analysis of infectious diseases with asymptomatic patients.

After over three years of COVID-19, it has become clear that infectious diseases are difficult to eradicate, and humans remain vulnerable under their influence in a long period. The presence of presymptomatic and asymptomatic patients is a significant obstacle to preventing and eliminating infectious diseases. However, the long-term transmission of infectious diseases involving asymptomatic patients still remains unclear. To address this issue, this paper develops a novel Markov process for infectious diseases with asymptomatic patients by means of a continuous-time level-dependent quasi-birth-and-death (QBD) process. The model accurately captures the transmission of infectious diseases by specifying several key parameters (or factors). To analyze the role of asymptomatic and symptomatic patients in the infectious disease transmission process, a simple sufficient condition for the stability of the Markov process of infectious diseases is derived using the mean drift technique. Then, the stationary probability vector of the QBD process is obtained by using RG-factorizations. A method of using the stationary probability vector is provided to obtain important performance measures of the model. Finally, some numerical experiments are presented to demonstrate the model's feasibility through analyzing COVID-19 as an example. The impact of key parameters on the system performance evaluation and the infectious disease transmission process are analyzed. The methodology and results of this paper can provide theoretical and technical support for the scientific control of the long-term transmission of infectious diseases, and we believe that they can serve as a foundation for developing more general models of infectious disease transmission.

Risk factors for complications and incomplete resection after endoscopic resection for duodenal submucosal tumors.

BACKGROUND AND AIM: Endoscopic resection (ER) has been used to remove submucosal tumors (SMTs) in recent years; however, duodenal ER is associated with high rates of immediate or delayed bleeding and perforation. Whether ER can be recommended for the treatment of duodenal SMTs remains controversial. Therefore, we aimed to investigate the clinical outcomes associated with the ER of duodenal SMTs and to assess possible predictive factors for complications and incomplete resection. METHODS: This retrospective study included 141 patients with duodenal SMTs. The therapeutic outcomes from ER and procedure-related complications were analyzed. RESULTS: Of the 141 patients, 78.7% achieved complete resection and nine (6.4%) developed complications. The multivariate analysis suggested that location near the duodenal papilla (P = 0.010) and diameter exceeding 15 mm (P = 0.091) of duodenal SMTs were independent risk factors for complications in ER. Besides, submucosal fibrosis (P = 0.042), location near the duodenal papilla (P = 0.049), and irregular morphology (P = 0.067) were independent risk factors for incomplete resection. CONCLUSIONS: ER can be recommended as an effective and minimally invasive treatment for duodenal SMTs.

Management of delayed bleeding of upper gastrointestinal endoscopic submucosal tunneling procedures: a retrospective single-center analysis and brief meta-analysis.

OBJECTIVES: Delayed bleeding is a rare but important major adverse event (mAE) after endoscopic submucosal tunneling procedures (ESTP), which is scarcely reported. We aimed to characterize the clinical characteristics of delayed bleeding and provide better management of this mAE. METHOD: From August 2010 to October 2022, we reviewed 3852 patients with achalasia receiving peroral endoscopic myotomy (POEM) and 1937 patients with upper gastrointestinal tumors receiving submucosal tunneling endoscopic resection (STER). Among these, records of 22 patients (15 POEM, 7 STER) with delayed bleeding were collected. Clinical characteristics, treatment, and outcomes of delayed bleeding were analyzed. RESULTS: The mean age was 43.6 years. Ten patients (45.5%) were intratunnel bleeding, seven (31.8%) were intratunnel bleeding accompanied by mucosal bleeding, and five (22.7%) were mucosal bleeding. The most common accompanied symptoms were hematemesis, fever, and melena. The most common accompanied mAEs were fistula, pulmonary inflammation, and pleural effusion with atelectasis. The mean duration from ESTP to endoscopic intervention was 5.3 ± 4.9 days. Active bleeding was identified in 21 patients (95.5%). The bleeding was successfully controlled by electrocoagulation (19 cases), endoscopic clipping (six cases), and Sengstaken-Blakemore tube insertion (three cases), and no patient required surgical intervention. The mean hemostatic procedure duration was 61.8 ± 45.8 min. The mean post-bleeding hospital stay was 10.0 ± 6.2 days. A brief meta-analysis of previous studies showed the pooled estimate delayed bleeding rate after POEM, STER, and G-POEM was 0.4%. CONCLUSIONS: Delayed bleeding is uncommon and could be effectively managed by timely emergency endoscopic procedures without requiring subsequent surgical interventions.

The role of type II esophageal microbiota in achalasia: Activation of macrophages and degeneration of myenteric neurons.

OBJECTIVE: The gut microbiota plays a critical role in the appropriate development and maintenance of the enteric nervous system (ENS). Esophageal achalasia (EA) is a rare motility disorder characterized by the selective degeneration of inhibitory neurons in the esophageal myenteric plexus. This study aimed to evaluate the composition of the esophageal microbiota in achalasia and explore the potential microbial mechanisms involved in its pathogenesis. DESIGN: The lower esophageal mucosal microbiota was analyzed in patients with achalasia and control participants using 16 S rRNA sequencing. The association between the esophageal microbiota and achalasia was validated by inducing esophageal dysbiosis in C57BL/10 J and C57BL/10ScNJ (TLR4KO) mice via chronic exposure to ampicillin sodium in their drinking water. RESULTS: The esophageal microbiota in EA patients had lower diversity and a predominance of Gram-negative bacteria (Type II microbiota) compared to that in the healthy controls. Additionally, the relative abundance of Rhodobacter decreased significantly in patients with achalasia, which correlated with an enrichment of lipopolysaccharide (LPS) biosynthesis based on the COG database. Antibiotic-treated mice showed an esophageal microbiota characterized by increased abundance of Gram-negative bacteria (Type II microbiome), decreased abundance of Rhodobacter, and enriched LPS biosynthesis. Compared to the control and TLR4KO mice, the antibiotic-treated wild-type mice had higher LES resting pressure, increased LES contraction rate after carbachol stimulation, and decreased relaxation response to L-arginine. Moreover, the number of myenteric neurons decreased, while the number of lamina propria macrophages (LpMs) increased after antibiotic exposure. Furthermore, the TLR4-MYD88-NF-κB pathway was up-regulated, and the production of TNF-α, IL-1ß, and IL-6 increased in the antibiotic-treated mice. CONCLUSIONS: Patients with achalasia exhibit esophageal dysbiosis, which may induce aberrant esophageal motility.

A single-cell transcriptional landscape of immune cells shows disease-specific changes of T cell and macrophage populations in human achalasia.

Achalasia is a rare motility disorder of the esophagus caused by the gradual degeneration of myenteric neurons. Immune-mediated ganglionitis has been proposed to underlie the loss of myenteric neurons. Here, we measure the immune cell transcriptional profile of paired lower esophageal sphincter (LES) tissue and blood samples in achalasia and controls using single-cell RNA sequencing (scRNA-seq). In achalasia, we identify a pattern of expanded immune cells and a specific transcriptional phenotype, especially in LES tissue. We show C1QC+ macrophages and tissue-resident memory T cells (TRM), especially ZNF683+ CD8+ TRM and XCL1+ CD4+ TRM, are significantly expanded and localized surrounding the myenteric plexus in the LES tissue of achalasia. C1QC+ macrophages are transcriptionally similar to microglia of the central nervous system and have a neurodegenerative dysfunctional phenotype in achalasia. TRM also expresses transcripts of dysregulated immune responses in achalasia. Moreover, inflammation increases with disease progression since immune cells are more activated in type I compared with type II achalasia. Thus, we profile the immune cell transcriptional landscape and identify C1QC+ macrophages and TRM as disease-associated immune cell subsets in achalasia.

Landscape of Psychological Profiles in Patients With Esophageal Achalasia.

INTRODUCTION: Esophageal achalasia (EA) is a chronic esophageal dysmotility disease, of which psychological distress was poorly understood. This study aims to assess the status of psychosocial characteristics in EA and to determine the relationship between psychological distress and EA. METHODS: Seventy pairs of age and gender-matched patients with EA and healthy control individuals were prospectively enrolled from December 2019 to April 2020 at our hospital. Demographic, psychosocial, and clinical data were obtained. Psychosocial assessments contained psychological distress (Symptom Checklist-90 Revised), perceived stress (Perceived Stress Scale-14), and stressful life events (Life Events Scale). Comparison for psychological parameters was made between patients with EA and controls as well as for EA before/after per oral endoscopic myotomy (POEM). Spearman rank correlation coefficients were used to testify the association between psychological distress and achalasia symptoms. RESULTS: The mean course and Eckardt score of patients with EA were 4.26 ± 5.11 years and 6.63 ± 2.21, respectively. There was a significant difference between patients with EA and healthy individuals in Global Severity Index ( P = 0.039) and Positive Symptoms Total ( P = 0.041) for Symptom Checklist-90 Revised as well as positive intensity ( P = 0.011) for the Life Events Scale. Somatization ( P < 0.001), anxiety ( P = 0.021), anger-hostility ( P = 0.009), and others (appetite and sleep, P = 0.010) accounted for the most difference. Somatization was positively associated with chest pain ( P = 0.045). Two patients with EA developed recurrence and showed no relationship with psychological status. Psychological status was significantly improved after POEM. DISCUSSION: Psychological distress, especially somatization, was more prevalent in patients with EA than healthy controls. POEM seemed able to improve psychological distress.

Salvage peroral endoscopic myotomy is a promising treatment for achalasia after myotomy failure.

BACKGROUND AND AIMS: Reintervention modalities after myotomy failure in achalasia patients have yet to be established. The efficacy and safety of salvage peroral endoscopic myotomy (POEM) for treatment of achalasia after myotomy failure were evaluated in the study. METHODS: Between August 2011 and August 2021 at the Endoscopy Center of Zhongshan Hospital, 219 achalasia patients who had previously undergone a myotomy underwent a salvage POEM and were thus retrospectively enrolled in this study. After propensity score matching (PSM), operation-related parameters were compared between the salvage POEM group and the naïve POEM group. Subgroup analysis was performed between patients with previous Heller myotomy (HM) and patients with previous POEM. RESULTS: With similar baseline characteristics between both groups after PSM, the salvage POEM group presented with shorter tunnel length (11.8 ± 2.2 cm vs 12.8 ± .9 cm, P < .0001) and myotomy length (9.8 ± 2.0 cm vs 10.4 ± 1.0 cm, P < .0001) than the naïve POEM group. No significant differences were found in procedure-related adverse events between patients of salvage POEM and naïve POEM. The primary outcome of treatment success occurred in 175 of 193 patients (90.7%) in the salvage POEM group versus 362 of 374 patients (96.8%) in the naïve POEM group (P = .0046). At a 2- and 5-year follow-up, significantly higher rates of clinical failures were observed in the previous HM subgroup than in the previous POEM subgroup (P = .0433 and P = .0230, respectively). CONCLUSIONS: Salvage POEM after a previous myotomy failure, especially after a POEM failure, is a promising treatment option because it has a durable clinical relief rate.

Endoscopic resection and suturing methods for non-ampullary duodenal submucosal tumors: "mini-invasive" treatments that should never be underestimated.

OBJECTIVE: To evaluate the effectiveness and safety of endoscopic resection and various suturing methods to treat non-ampullary duodenal submucosal tumors (NAD-SMTs). DESIGN: We performed a retrospective observational study of patients with NAD-SMTs who underwent endoscopic resection at Zhongshan Hospital, Fudan University, China, between June 2017 and December 2020. Data on patient characteristics, treatments and follow-up results were collected. The association between clinicopathologic characteristics and different suturing methods or adverse events were analyzed. RESULTS: Of 128 patients analyzed, 26 underwent endoscopic mucosal resection (EMR), 64 underwent endoscopic submucosal excavation (ESE), and 38 underwent endoscopic full-thickness resection (EFTR). EMR and ESR are both appropriate for non-full-thickness lesions, whereas ESE is more appropriate for tumors located in the bulb or descending duodenum. Gastric tube drainage is more strongly recommended after ESE. Satisfactory suturing is also vital endoscopic resection of NAD-SMTs. Metallic clips are often used in EMR or ESE of non-full-thickness lesions. The pathological findings revealed that the full-thickness lesions were predominantly gastrointestinal stromal tumors (GIST), Brunner's tumor or lipoma, and the surgeons usually used purse-string sutures to close the wounds. The operation time was longer for purse-string suture closure than metallic clip closure. Eleven patients had complications. Risk factors for adverse events included large-diameter tumor (≥ 2 cm), location in the descending part of the duodenum, involvement of the fourth layer of the duodenal wall, EFTR, and GIST. CONCLUSIONS: Endoscopic resection of NAD-SMTs is effective but is associated with a high incidence of complications due to their anatomical peculiarities. Preoperative diagnosis is quite important. Careful selection of treatment and suturing methods are necessary to reduce the risk of adverse effects. Given the increased frequency of severe complications during or following duodenal endoscopic resection, this procedure should be performed by experienced endoscopists.

Muscular injury as an independent risk factor for esophageal stenosis after endoscopic submucosal dissection of esophageal squamous cell cancer.

BACKGROUND AND AIMS: Stenosis after esophageal endoscopic submucosal dissection (ESD) has a high incidence, and muscular injury is an important risk factor for esophageal stenosis. Hence, this study aimed to classify muscular injury degrees and investigate their association with postoperative stenosis. METHODS: This retrospective study included 1033 patients with esophageal mucosal lesions treated with ESD between August 2015 and March 2021. Demographic and clinical parameters were analyzed, and stenosis risk factors were identified using multivariate logistic regression. A novel muscular injury classification system was proposed and used to investigate the association between different muscular injury degrees and postoperative stenosis. Finally, a scoring system was established to predict muscular injury. RESULTS: Of 1033 patients, 118 (11.4%) had esophageal stenosis. The multivariate analysis demonstrated that the history of endoscopic esophageal treatment, circumferential range, and muscular injury were significant risk factors for esophageal stenosis. Patients with type II muscular injuries tended to develop complex stenosis (n = 13 [36.1%], P < .05), and type II muscular injuries were more likely to predispose patients to severe stenosis than type I (73.3% and 92.3%, respectively). The scoring system showed that patients with high scores (3-6) were more likely to have muscular injury. The score model presented good discriminatory power in the internal validation (area under the receiver-operating characteristic curve, .706; 95% confidence interval, .645-.767) and goodness-of-fit in the Hosmer-Lemeshow test (P = .865). CONCLUSIONS: Muscular injury was an independent risk factor for esophageal stenosis. The scoring system demonstrated good performance in predicting muscular injury during ESD.

Clinical outcomes of endoscopic resection for the treatment of esophageal gastrointestinal stromal tumors: a ten-year experience from a large tertiary center in China.

BACKGROUNDS: Esophageal gastrointestinal stromal tumors (E-GISTs) are extremely rare and surgical resection is the recommended approach. However, surgical resection usually causes severe trauma that may result in significant postoperative morbidity. Endoscopic resection (ER) has developed rapidly in recent years and has been widely used in gastrointestinal lesions. Nevertheless, the feasibility and efficacy of ER in the management of E-GISTs are unknown. METHODS: Retrospective data were collected from January 2011 to December 2020 in a large tertiary center of China. Twenty-eight patients with E-GISTs treated by ER were included in the study. RESULTS: Of the 28 patients, there were 21 males and 7 females, with a median age of 55 years (40-70 years). The median tumor size was 15 mm (5-80 mm). The technical success rate was 100% (28/28), while the en bloc resection rate was 96.4% (27/28). The median operation time was 35 min (10-410 min). Sixteen (57.2%) tumors were categorized into very low risk group, six (21.4%) into low risk group, and six (21.4%) into high risk group. Pathologists carefully examined margins of each lesion. There were 11 lesions (39.3%) determined as R0 resection and 17 lesions (60.7%) as R1 resection with positive margins. The median hospital stay was 2 days (range, 1-8 days). One patient suffered from hydrothorax and required drainage, leading to a major adverse event rate of 3.6% (1/28). There was no conversion to surgery, and no death occurred within 30 days after the procedure. Imatinib was given to two patients after ER under multidisciplinary team surveillance. During follow-up (median of 54 months, 9-122 months), no recurrences or metastasis were observed. CONCLUSION: ER is safe and effective for E-GISTs and might become an optional choice in the future. Multicenter, prospective, large samples with long-term follow-up studies are still needed.

Improving bowel preparation for colonoscopy with a smartphone application driven by artificial intelligence.

Optimal bowel preparation is a prerequisite for a successful colonoscopy; however, the rate of inadequate bowel preparation remains relatively high. In this study, we establish a smartphone app that assesses patient bowel preparation using an artificial intelligence (AI)-based prediction system trained on labeled photographs of feces in the toilet and evaluate its impact on bowel preparation quality in colonoscopy outpatients. We conduct a prospective, single-masked, multicenter randomized clinical trial, enrolling outpatients who own a smartphone and are scheduled for a colonoscopy. We screen 578 eligible patients and randomize 524 in a 1:1 ratio to the control or AI-driven app group for bowel preparation. The study endpoints are the percentage of patients with adequate bowel preparation and the total BBPS score, compliance with dietary restrictions and purgative instructions, polyp detection rate, and adenoma detection rate (secondary). The prediction system has an accuracy of 95.15%, a specificity of 97.25%, and an area under the curve of 0.98 in the test dataset. In the full analysis set (n = 500), adequate preparation is significantly higher in the AI-driven app group (88.54 vs. 65.59%; P < 0.001). The mean BBPS score is 6.74 ± 1.25 in the AI-driven app group and 5.97 ± 1.81 in the control group (P < 0.001). The rates of compliance with dietary restrictions (93.68 vs. 83.81%, P = 0.001) and purgative instructions (96.05 vs. 84.62%, P < 0.001) are significantly higher in the AI-driven app group, as is the rate of additional purgative intake (26.88 vs. 17.41%, P = 0.011). Thus, our AI-driven smartphone app significantly improves the quality of bowel preparation and patient compliance.

A complete algebraic solution to the optimal dynamic rationing policy in the stock-rationing queue with two demand classes.

In this paper, we study a stock-rationing queue with two demand classes by means of the sensitivity-based optimization, and develop a complete algebraic solution to the optimal dynamic rationing policy. We show that the optimal dynamic rationing policy must be of transformational threshold type. Based on this finding, we can refine three sufficient conditions under each of which the optimal dynamic rationing policy is of threshold type (i.e., critical rationing level). To do this, we use the performance difference equation to characterize the monotonicity and optimality of the long-run average profit of this system, and thus establish some new structural properties of the optimal dynamic rationing policy by observing any given reference policy. Finally, we use numerical experiments to demonstrate our theoretical results of the optimal dynamic rationing policy. We believe that the methodology and results developed in this paper can shed light on the study of stock-rationing queue and open a series of potentially promising research.

Endoscopic mucosal resection of gastrointestinal polyps with a novel low-temperature plasma radio frequency generator: a non-inferiority multi-center randomized control study.

BACKGROUND: To evaluate the efficacy and safety of novel plasma radio frequency generator and its single-use polypectomy snares for endoscopic mucosal resection (EMR) of gastrointestinal (GI) polyps. METHODS: A total of 217 patients with 413 GI polyps were recruited from four centers in China. Patients were assigned to experimental or control groups using a central randomization method. The experimental group used the novel plasma radio frequency generator and its matched single-use polypectomy snares (Neowing, Shanghai), while the control group used the high-frequency electrosurgical unit (Erbe, Germany) and disposable electrosurgical snares (Olympus, Japan). The primary endpoint was the en bloc resection rate, and the non-inferiority margin was set at 10%. Secondary endpoint included operation time, coagulation success rate, intraoperative and postoperative bleeding rate, and perforation rate. RESULTS: The en bloc resection rate was 97.20% (104/107) in the experimental group and 95.45% (105/110) in the control group (P = 0.496). The operation time was 29.14 ± 20.21 min in the experimental group and 30.26 ± 18.74 min in the control group (P = 0.671). The average removal time of a single polyp in the experimental group was 7.52 ± 4.45 min, which was slightly shorter than that in the control group 8.90 ± 6.67 min, with no statistical difference (P = 0.076). The intraoperative bleeding rates of the experimental group and control group were 8.41% (9/107) and 10.00% (11/110), respectively (P = 0.686). No intraoperative perforation occurred in either group. The postoperative bleeding rates of the experimental group and the control group were 1.87% (2/107) and 4.55% (5/110), respectively (P = 0.465). No postoperative perforation occurred in the experimental group (0/107), while one case of delayed perforation occurred in the control group (1/110, 0.91%). There was no statistical difference between the two groups. CONCLUSIONS: Endoscopic mucosal resection of GI polyps with the novel plasma radio frequency generator is safe and effective, and non-inferior to the conventional high-frequency electrosurgical system.