Long-term outcomes of endoscopic resection of superficial esophageal squamous cell carcinoma in late-elderly patients.

BACKGROUND AND AIM: As the population ages, the number of elderly patients with superficial esophageal squamous cell carcinoma (ESCC) is increasing. We aimed to clarify the indications for endoscopic resection (ER) in late-elderly patients with ESCC in terms of life expectancy. METHODS: Patients aged ≥75 years who underwent ER for ESCC at our institution from January 2005 to December 2018 were enrolled. Clinical data, including the Eastern Cooperative Oncology Group performance status, American Society of Anesthesiologists physical status (ASA-PS), Charlson comorbidity index, and prognostic nutritional index (PNI), were collected at the time of ER. The main outcome measure was overall survival (OS). RESULTS: Two hundred eight consecutive patients were enrolled. The patients' median age was 78 years (range, 75-89 years). The 5-year follow-up rate was 88.5% (median follow-up period, 6.6 years). The 5-year OS rate was 79.2% (95% confidence interval [CI], 72.2-84.8), and 5-year net survival standardized for age, sex, and calendar year was 1.04 (95% CI, 0.98-1.09). In the multivariate analysis, an ASA-PS of 3 (hazard ratio, 2.45; 95% CI, 1.16-5.17) and PNI of <44.0 (hazard ratio, 2.73; 95% CI, 1.38-5.40) were independent prognostic factors. When neither of these factors was met, the 5-year OS rate was 87.8% (95% CI, 80.0-92.9), and 5-year net survival was 1.08 (95% CI, 1.02-1.14). CONCLUSIONS: ER for ESCC in late-elderly patients may improve life expectancy. ER is recommended in patients with a good ASA-PS and PNI.

Clinical Significance of Prior Ramucirumab Use on the Effectiveness of Nivolumab as the Third-Line Regimen in Gastric Cancer: A Multicenter Retrospective Study.

BACKGROUND AND OBJECTIVE: Because vascular endothelial growth factor inhibition has been suggested to improve immune cell function in the cancer microenvironment, we examined whether using ramucirumab (RAM) before nivolumab usage is more effective in advanced gastric cancer. METHODS: This was a multicenter retrospective observational study. We analyzed patients who received nivolumab monotherapy as the third-line regimen for unresectable advanced or recurrent gastric cancer between October 2017 and December 2022. They were divided into the RAM (RAM-treated) group and the non-RAM (non-treated) group according to the RAM usage in the second-line regimen. The primary outcome was to compare the overall survival after nivolumab administration in the third-line regimen between the RAM and non-RAM groups. RESULTS: Fifty-two patients were included in the present study: 42 patients in the RAM group and ten patients in the non-RAM group. The median overall survival was significantly longer in the RAM group than in the non-RAM group (8.5 months vs 6.9 months, p < 0.05). In the RAM group, patients without peritoneal metastasis had significantly better median overall survival than those with peritoneal metastasis (23.8 months vs 7.7 months, p = 0.0033). Multivariate Cox-proportional hazards analyses showed that the presence of peritoneal metastasis (hazard ratio, 2.4; 95% confidence interval 1.0-5.7) alone was significantly associated with overall survival in the RAM group. CONCLUSIONS: The use of RAM prior to nivolumab monotherapy may contribute to prolonged survival in patients with gastric cancer, especially those without peritoneal metastasis.

Live Streaming of the Professor's Ward Rounds in Undergraduate Neurology Education: Usability Study.

BACKGROUND: Although neurology department ward rounds are among the most important medical education exercises in Japan, they have several issues. Patients may find it unpleasant to undergo repeated neurological tests, especially when in the presence of several students. Only the front row of students can closely observe the examination findings; moreover, students were prohibited from contacting patients altogether during the COVID-19 pandemic. One possible solution is to use commercial videoconferencing systems. However, Japanese patients are reluctant to have their medical information or video footage of them sent outside of the hospital via the internet. OBJECTIVE: The study aimed to confirm the feasibility of conducting remote teaching rounds using an in-house web conferencing system in which the patients' personal data are securely protected. This study also explored whether using remote rounds alongside face-to-face participation would enhance learning. METHODS: We created an on-premises videoconferencing system using an open-source app. To perform video ward rounds, the professor wore a wireless microphone while leading routine in-person rounds and the attending physician carried a tablet device linked to a web conference, allowing students in another room to watch the rounds on a live stream. In total, 112 of 5th-year students who entered their 1-week neurology rotation between 2021 and 2022 were instructed to participate in 1-hour in-person and remote rounds. Students were given questionnaires to evaluate their satisfaction and the educational effects of the remote rounds. RESULTS: The remote ward rounds were conducted easily with no interference with the in-person rounds, nor any complaints from the patients. Each examination technique was explained by another teacher to the students who participated in remote rounds in the conference room. Characteristic neurological findings, such as plantar reflexes (Babinski sign), which are usually seen only by close observers during in-person rounds, could be visualized under magnification by all students. The postexperience survey (82/112, 73% response rate) showed that the mean score of participants' satisfaction was 3.94 (SD 0.83; excellent 5 and poor 1). No participant scoring 1 was noted. The proportion of students who observed 6 representative abnormal neurological findings (Babinski sign, hyperreflexia, cerebellar ataxia, involuntary movement, muscular weakness, and abnormality in sensory examination) increased by 22% (18/82, range 13-24) compared to in-person rounds alone. When self-rating the learning value, 43% (35/82) of the students answered that remote rounds are equally as valuable as in-person rounds, while 32% (26/82) preferred remote rounds. CONCLUSIONS: Live-streaming of neurology ward rounds using a secure in-house web conferencing system provides additional learning experience without concerns regarding leakage of patient information. This initiative could enhance neurology learning before entering a clinical clerkship.

Characteristics of Early Gastric Cancer in a Patient with a History of Helicobacter pylori Infection and No History of Eradication Therapy.

Objective The characteristics of gastric cancer in patients with atrophic mucosa and no apparent history of Helicobacter pylori eradication have not been thoroughly investigated. Therefore, this study examined the clinicopathological characteristics of gastric cancer in these patients. Methods We retrospectively examined the endoscopic and pathological characteristics of gastric cancer in patients who underwent endoscopic submucosal dissection. Patients or Materials We divided the patients into 2 groups: those with gastric atrophy and no history of eradication (group A; n =102) and those with a history of eradication (group B; n =161). In group A, patients were further divided into mild atrophy (group C) and severe atrophy (group D) groups, while group B was further divided into those who underwent eradication treatment >5 years ago (group E) and those who underwent eradication 1-5 years ago (group F). Results Group A comprised significantly older individuals (75±8.0 vs. 71±7.5 years old, p <0.001) with a higher frequency of elevated gastric cancer than group B (32.4% vs. 17.4%, p =0.006). Compared with group E, group A was older and had a greater incidence of elevated gastric cancer. The incidence of gastric cancer in the U or M region was lower in group C than in group D. Conclusion Gastric cancer in patients with gastric atrophy and no history of eradication was associated with an older age and higher frequency of elevated-type morphology than in those with a history of eradication.

Drug-induced mucosal alterations observed during esophagogastroduodenoscopy.

Several features of drug-induced mucosal alterations have been observed in the upper gastrointestinal tract, i.e., the esophagus, stomach, and duodenum. These include pill-induced esophagitis, desquamative esophagitis, worsening of gastroesophageal reflux, chemotherapy-induced esophagitis, proton pump inhibitor-induced gastric mucosal changes, medication-induced gastric erosions and ulcers, pseudomelanosis of the stomach, olmesartan-related gastric mucosal inflammation, lanthanum deposition in the stomach, zinc acetate hydrate tablet-induced gastric ulcer, immune-related adverse event gastritis, olmesartan-asso-ciated sprue-like enteropathy, pseudomelanosis of the duodenum, and lanthanum deposition in the duodenum. For endoscopists, acquiring accurate knowledge regarding these diverse drug-induced mucosal alterations is crucial not only for the correct diagnosis of these lesions but also for differential diag-nosis of other conditions. This minireview aims to provide essential information on drug-induced mucosal alterations observed on esophagogastroduodenoscopy, along with representative endoscopic images.

Endoscopic and Histological Gastritis in University Students with Helicobacter pylori Infection.

Objective Although the characteristics of Helicobacter pylori infection have been extensively reported, there is a lack of consensus regarding its characteristics in young adults. The present study examined the endoscopic and histological characteristics of young adults who underwent eradication therapy for H. pylori infection. Methods We examined the H. pylori infection status of first-year students at Okayama University School of Medicine and Dentistry between 2014 and 2020. A total of 152 (6.8%) students who were positive for H. pylori antibody or pepsinogen tests were enrolled in the study. Among them, 107 students underwent endoscopy, and their biopsy samples were investigated. Seventy-five students were diagnosed with H. pylori infections. Results Of 75 H. pylori-positive patients, 57 (76.0%) had endoscopic atrophic gastritis, and 42 (56.0%) had histological atrophy. A few patients had severe atrophic gastritis. All 65 patients who underwent an eradication assessment were successfully treated. After successful eradication, 26 patients underwent endoscopic follow-up. The mean follow-up period was 32.9 months. A histological evaluation revealed that gastric antrum atrophy had subsided in 11 of 14 patients, and atrophy in the lesser curvature of the gastric body had subsided in 7 of 8 patients. Conclusion More than half of young adults with H. pylori infection had atrophic gastritis. We found mild atrophy in young adults, which subsided shortly after eradication treatment. This study provides a foundation for future studies to evaluate the validity of eradication therapy in preventing gastric cancer in patients.

Clinical significance of gastrointestinal bleeding history in patients who undergo left atrial appendage closure.

Background and Aim: Anticoagulant users with nonvalvular atrial fibrillation (NVAF) sometimes suffer from gastrointestinal bleeding (GIB) and have difficulty continuing the medication. Left atrial appendage closure (LAAC) has been developed for such situations. We aimed to clarify the clinical significance of a history of GIB in comparison to other factors in patients who had undergone LAAC. Methods: From October 2019 to September 2023, patients with NVAF who underwent LAAC at our hospital were enrolled. We investigated the percentage of patients with a history of GIB who underwent LAAC and compared the incidence of post-LAAC bleeding in these patients compared to those with other factors. Results: A total of 45 patients were included. There were 19 patients (42%) with a history of GIB who underwent LAAC. In a Kaplan-Meier analysis, the cumulative incidence of bleeding complications after LAAC was significantly higher in patients with a history of GIB in comparison to patients with other factors. There were eight cases of post-LAAC bleeding in total, and seven cases had GIB. Conclusions: We need to recognize that GIB is a significant complication in patients who undergo LAAC. The management of GIB by gastroenterologists is essential to the success of LAAC.

Innovative submucosal injection solution for endoscopic resection with phosphorylated pullulan: a preclinical study.

BACKGROUND AND AIMS: A submucosal injection solution is used to assist in endoscopic surgery. The high viscosity of current solutions makes them difficult to inject. In the present study, we developed an extremely low-viscosity, easy-to-use submucosal injection solution using phosphorylated pullulan (PPL). METHODS: The PPL solutions were prepared at different concentrations, and their viscosities were measured. The mucosal elevation capacity was evaluated using excised porcine stomachs. Controls included 0.4% sodium hyaluronate (SH), 0.6% sodium alginate (SA), and saline. To evaluate the practicality, the catheter injectability of 0.7% PPL was measured, and EMR and endoscopic submucosal dissection (ESD) were performed using the stomach and colorectum of live pigs. As controls, 0.4% SH and saline were used. RESULTS: The PPL solutions were of extremely low viscosity compared to the solutions of 0.4% SH and 0.6% SA. Nevertheless, the mucosal elevation capacity of PPL solutions for up to 0.7% concentration was similar to that of 0.4% SH, and 0.7% PPL was less resistant to catheter infusion than 0.4% SH and 0.6% SA. In live pig experiments with endoscopic mucosal resection and ESD, snaring after submucosal injection of 0.7% PPL was easier than with 0.4% SH, ESD with 0.7% PPL produced less bubble formation than with 0.4% SH, and the procedure time tended to be shorter with 0.7% PPL than with 0.4% SH because of the shorter injection time. CONCLUSIONS: The PPL solution is an innovative and easy-to-use submucosal injection solution.

Nationwide multicenter study on adverse events associated with a patency capsule: Additional survey of appropriate use of patency capsule study.

BACKGROUND AND AIM: The PillCam patency capsule (PC) without a radio frequency identification tag was released to preclude retention of the small bowel capsule endoscope (CE) in Japan in 2012. We conducted a multicenter study to determine tag-less PC-related adverse events (AEs). METHODS: We first conducted a retrospective survey using a standardized data collection sheet for the clinical characteristics of PC-related AEs among 1096 patients collected in a prospective survey conducted between January 2013 and May 2014 (Cohort 1). Next, we retrospectively investigated additional AEs that occurred before and after Cohort 1 within the period June 2012 and December 2014 among 1482 patients (Cohort 2). RESULTS: Of the 2578 patients who underwent PC examinations from both cohorts, 74 AEs occurred among 61 patients (2.37%). The main AEs were residual parylene coating in 25 events (0.97%), PC-induced small bowel obstruction, suspicious of impaction, in 23 events (0.89%), and CE retention even after patency confirmation in 10 events (0.39%). Residual parylene coating was significantly associated with Crohn's disease (P < 0.01). Small bowel obstruction was significantly associated with physicians with less than 1 year of experience handling the PC and previous history of postprandial abdominal pain (P < 0.01 and P < 0.03, respectively). CE retention was ascribed to erroneous judgment of PC localization in all cases. CONCLUSIONS: This large-scale multicenter study provides evidence supporting the safety and efficiency of a PC to preclude CE retention. Accurate PC localization in patients without excretion and confirmation of previous history of postprandial abdominal pain before PC examinations is warranted (UMIN000010513).

Successful use of dupilumab for egg-induced eosinophilic gastroenteritis with duodenal ulcer: a pediatric case report and review of literature.

BACKGROUND: Non-esophageal eosinophilic gastrointestinal disorder (non-EoE-EGID) is a rare disease in which eosinophils infiltrate parts of the gastrointestinal tract other than the esophagus; however, the number of patients with non-EoE-EGID has been increasing in recent years. Owing to its chronic course with repeated relapses, it can lead to developmental delays due to malnutrition, especially in pediatric patients. No established treatment exists for non-EoE-EGID, necessitating long-term systemic corticosteroid administration. Although the efficacy of dupilumab, an anti-IL-4/13 receptor monoclonal antibody, for eosinophilic esophagitis, has been reported, only few reports have demonstrated its efficacy in non-EoE EGIDs. CASE PRESENTATION: A 13-year-old boy developed non-EoE-EGID with duodenal ulcers, with chicken eggs as the trigger. He was successfully treated with an egg-free diet, proton pump inhibitors, and leukotriene receptor antagonists. However, at age 15, he developed worsening upper abdominal pain and difficulty eating. Blood analysis revealed eosinophilia; elevated erythrocyte sedimentation rate; and elevated levels of C-reactive protein, total immunoglobulin E, and thymic and activation-regulated chemokines. Upper gastrointestinal endoscopy revealed a duodenal ulcer with marked mucosal eosinophilic infiltration. Gastrointestinal symptoms persisted even after starting systemic steroids, making it difficult to reduce the steroid dose. Subcutaneous injection of dupilumab was initiated because of comorbid atopic dermatitis exacerbation. After 3 months, the gastrointestinal symptoms disappeared, and after 5 months, the duodenal ulcer disappeared and the eosinophil count decreased in the mucosa. Six months later, systemic steroids were discontinued, and the duodenal ulcer remained recurrence-free. The egg challenge test result was negative; therefore, the egg-free diet was discontinued. Blood eosinophil count and serum IL-5, IL-13, and eotaxin-3 levels decreased after dupilumab treatment. The serum levels of IL-5 and eotaxin-3 remained within normal ranges, although the blood eosinophil counts increased again after discontinuation of oral prednisolone. CONCLUSIONS: Suppression of IL-4R/IL-13R-mediated signaling by dupilumab may improve abdominal symptoms and endoscopic and histologic findings in patients with non-EoE-EGID, leading to the discontinuation of systemic steroid administration and tolerance of causative foods.

Idiopathic Gastric Antral Ulcers.

A Japanese woman presented with gastric antral ulcers accompanied by erosion and edema, demonstrating a chronic pattern of improvement and recurrence for more than six years. The patient had no relevant treatment history, and Helicobacter pylori infection was ruled out. Other potential etiologies contributing to gastric ulcers were eliminated on the basis of endoscopic biopsy and blood laboratory findings. Consequently, the patient was diagnosed with idiopathic gastric antral ulcer. This disease is often overlooked, and the chronological endoscopic images provided in this report can be used as a reference.

Optimal Bowel Preparation Method to Visualize the Distal Ileum via Small Bowel Capsule Endoscopy.

Small bowel capsule endoscopy (SBCE) is a convenient and minimally invasive method widely used to evaluate the small intestine. However, especially in the distal ileum, visualization of the intestinal mucosa is frequently hampered by the remaining intestinal contents, making it difficult to detect critical lesions. Although several studies have reported on the efficacy of bowel preparation before SBCE, no standardized protocol has been established. Herein, we determined the optimal preparation method for better visualization of the distal ileum using SBCE. We retrospectively analyzed 259 consecutive patients who had undergone SBCE between July 2009 and December 2019, divided into three groups: Group A (no preparation except overnight fasting), Group B (ingestion of 1-2 L polyethylene glycol 4 h before colonoscopy after overnight fasting and performing SBCE immediately after colonoscopy), and Group C (ingestion of 0.9 L magnesium citrate [MC] before SBCE after overnight fasting). The visibility of the intestinal mucosa in the first 10 min and at the last 10 min during the period of observation of the distal ileum was examined using a scoring system and compared. The visibility of the images captured by SBCE was assessed based on the scoring of the degree of bile/chyme staining, residual fluid and debris, brightness, bubble reduction, and visualized mucosa. The status of intestinal collapse was also assessed. In the first 10 min of observation of the distal ileum, no significant differences were detected among the groups. In the last 10 min, significantly better images were acquired in Group C in terms of bile/chyme staining, brightness, bubble reduction, and visualized mucosa. Bowel preparation using a low-dose MC solution 2 h before SBCE provided significantly higher-quality images of the distal ileum. Further optimization, such as the timing of initiating the preparation, is necessary to determine the optimal regimen for bowel preparation prior to SBCE.

Endoscopic features of gastric neuroendocrine carcinoma.

BACKGROUND AND AIM: The endoscopic features of gastric neuroendocrine carcinoma (G-NEC) have not been clarified; therefore, they were investigated in relation to clinicopathological findings. METHODS: Consecutive patients with G-NECs who had undergone endoscopic or surgical resection at our institution between January 2005 and March 2022 were included in this retrospective study. The endoscopic and clinicopathological findings of the lesions were analyzed to provide information of diagnostic value. In addition, cases of gastric neuroendocrine tumor (G-NET) and common-type gastric adenocarcinoma treated in the same study period were identified to compare the endoscopic findings between each G-NEC versus G-NET, and G-NEC versus common-type gastric adenocarcinoma. Patients with common-type gastric adenocarcinoma were matched for age, sex, tumor size, and depth of tumor invasion in 1:3 ratio. RESULTS: Among 15 patients with 15 G-NECs, submucosal tumor-like marginal elevation (87%), adherent white coat (67%), and ulceration with a distinct border (60%) were characteristic endoscopic findings in white-light images. Magnifying narrow-band imaging endoscopy revealed an absent microsurface (MS) pattern plus disrupted irregular microvessel (MV) in five (71%) of seven cases with evaluable MS and MV patterns. The area with an absent MS pattern plus disrupted irregular MV corresponded to the histological finding of NEC component in all five cases. These endoscopic features were all significantly more frequent in G-NECs than G-NETs (n = 22) or common-type gastric adenocarcinomas (n = 45). CONCLUSIONS: These endoscopic features should be taken into consideration to increase the index of suspicion and to improve the accuracy of target biopsies for G-NEC.

Review of oral and pharyngolaryngeal benign lesions detected during esophagogastroduodenoscopy.

Recent advancements in endoscopy equipment have facilitated endoscopists' detection of neoplasms in the oral cavity and pharyngolaryngeal regions. In particular, image-enhanced endoscopy using narrow band imaging or blue laser imaging play an integral role in the endoscopic diagnosis of oral and pharyngolaryngeal cancers. Despite these advancements, limited studies have focused on benign lesions that can be observed during esophagogastroduodenoscopy in the oral and pharyngolaryngeal regions. Therefore, this mini-review aimed to provide essential information on such benign lesions, along with representative endoscopic images of dental caries, cleft palate, palatal torus, bifid uvula, compression by cervical osteophytes, tonsil hyperplasia, black hairy tongue, oral candidiasis, oral and pharyngolaryngeal ulcers, pharyngeal melanosis, oral tattoos associated with dental alloys, retention cysts, papilloma, radiation-induced changes, skin flaps, vocal cord paresis, and vocal fold leukoplakia. Whilst it is imperative to seek consultation from otolaryngologists or dentists in instances where the diagnosis cannot be definitively ascertained by endoscopists, the merits of attaining foundational expertise pertaining to oral and pharyngolaryngeal lesions are unequivocal. This article will be a valuable resource for endoscopists seeking to enhance their understanding of oral and pharyngolaryngeal lesions.

Exosomes derived from synovial fibroblasts from patients with rheumatoid arthritis promote macrophage migration that can be suppressed by miR-124-3p.

Objectives: Exosomes are potent vehicles for intercellular communication. Rheumatoid arthritis (RA) is a chronic systemic disease of unknown etiology. Local administration of miR-124 precursor to rats with adjuvant-induced arthritis suppresses systemic arthritis and bone destruction. Thus, exosomes may be involved in this disease. We aimed to determine the role of exosomes in the pathology of RA. Methods: Fibroblast-like synoviocytes (FLS) were collected from patients with RA and osteoarthritis (OA). miR-124-3p mimic was transfected into the RA FLS (RA miR-124 FLS). Exosomes were collected from the culture medium by ultracentrifugation. Macrophages were produced from THP-1 cells. MicroRNAs in the exosomes were analyzed using real-time PCR. Proteomics analysis was performed using nanoscale liquid chromatography-tandem mass spectrometry. Macrophage migration was evaluated using a Transwell migration assay. SiRNA was used to knockdown proteins of interest. Results: MicroRNAs in the RA FLS, RA miR-124 FLS, and OA FLS exosomes were similar. Proteomics analysis revealed that pentraxin 3 (PTX3) levels were higher in RA FLS exosomes than in RA miR-124 FLS and OA FLS exosomes, and proteasome 20S subunit beta 5 (PSMB5) levels were lower in RA FLS exosomes than in RA miR-124 FLS and OA FLS exosomes. The RA FLS exosomes promoted and the RA miR-124 FLS exosomes suppressed macrophage migration. PTX3-silenced RA FLS exosomes suppressed and PSMB5-silenced OA FLS exosomes promoted macrophage migration. Conclusions: RA FLS exosomes promote macrophage migration via PTX3 and PSMB5, and miR-124-3p suppresses this migration.

Degree of pharyngeal deformation caused by pharyngeal endoscopic submucosal dissection is associated with the incidence of aspiration pneumonia.

Background and study aims Endoscopic submucosal dissection (ESD) is one of the most minimally invasive treatments for superficial squamous cell cancer of the pharynx. However, aspiration pneumonia (AsP) associated with postoperative deformity of the pharynx may occur. The purpose of this study was to investigate the frequency of AsP and the degree of pharyngeal deformity after pharyngeal ESD. Patients and methods This was a retrospective observational study of patients who underwent pharyngeal ESD at Okayama University Hospital between 2006 and 2017. The degree of pharyngeal deformation was assessed using the pharyngeal deformation grade (PDG). The primary endpoint was the frequency of AsP as a long-term adverse event. Results Among the 52 patients enrolled, nine developed aspiration pneumonia, with a 3-year cumulative incidence of 9.0 % (95 % confidence interval [CI], 3.3 %-22.0 %). There were 16, 18, 16, and two patients that had PDG 0, 1, 2, and 3, respectively. Patients with a history of radiotherapy, as a treatment of head and neck cancer (44.4 % vs. 11.6 %; P  = 0.02) and the high PDG group (PDG 2 and 3) (77.8 % vs. 25.6 %; P  = 0.005) had a significantly higher incidence of AsP. The 3-year cumulative incidence rate of AsP after ESD in the high PDG group was significantly higher than that in the low PDG group (PDG 0 and 1) (23.9 % [95 %CI, 9.2.-49.5%] vs. 0 %; P  = 0.03). Conclusions The incidence of aspiration pneumonia in the long-term course after pharyngeal ESD was revealed. The incidence of aspiration pneumonia may be associated with pharyngeal deformity, but further studies are needed.

Improved Object Detection Artificial Intelligence Using the Revised RetinaNet Model for the Automatic Detection of Ulcerations, Vascular Lesions, and Tumors in Wireless Capsule Endoscopy.

The use of computer-aided detection models to diagnose lesions in images from wireless capsule endoscopy (WCE) is a topical endoscopic diagnostic solution. We revised our artificial intelligence (AI) model, RetinaNet, to better diagnose multiple types of lesions, including erosions and ulcers, vascular lesions, and tumors. RetinaNet was trained using the data of 1234 patients, consisting of images of 6476 erosions and ulcers, 1916 vascular lesions, 7127 tumors, and 14,014,149 normal tissues. The mean area under the receiver operating characteristic curve (AUC), sensitivity, and specificity for each lesion were evaluated using five-fold stratified cross-validation. Each cross-validation set consisted of between 6,647,148 and 7,267,813 images from 217 patients. The mean AUC values were 0.997 for erosions and ulcers, 0.998 for vascular lesions, and 0.998 for tumors. The mean sensitivities were 0.919, 0.878, and 0.876, respectively. The mean specificities were 0.936, 0.969, and 0.937, and the mean accuracies were 0.930, 0.962, and 0.924, respectively. We developed a new version of an AI-based diagnostic model for the multiclass identification of small bowel lesions in WCE images to help endoscopists appropriately diagnose small intestine diseases in daily clinical practice.