Machine learning models to predict submucosal invasion in early gastric cancer based on endoscopy features and standardized color metrics.

Conventional endoscopy is widely used in the diagnosis of early gastric cancers (EGCs), but the graphical features were loosely defined and dependent on endoscopists' experience. We aim to establish a more accurate predictive model for infiltration depth of early gastric cancer including a standardized colorimetric system, which demonstrates promising clinical implication. A retrospective study of 718 EGC cases was performed. Clinical and pathological characteristics were included, and Commission Internationale de l'Eclariage (CIE) standard colorimetric system was used to evaluate the chromaticity of lesions. The predicting models were established in the derivation set using multivariate backward stepwise logistic regression, decision tree model, and random forest model. Logistic regression shows location, macroscopic type, length, marked margin elevation, WLI color difference and histological type are factors significantly independently associated with infiltration depth. In the decision tree model, margin elevation, lesion located in the lower 1/3 part, WLI a*color value, b*color value, and abnormal thickness in enhanced CT were selected, which achieved an AUROC of 0.810. A random forest model was established presenting the importance of each feature with an accuracy of 0.80, and an AUROC of 0.844. Quantified color metrics can improve the diagnostic precision in the invasion depth of EGC. We have developed a nomogram model using logistic regression and machine learning algorithms were also explored, which turned out to be helpful in decision-making progress.

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.

Characteristics of early gastric tumors with different differentiation and predictors of long-term outcomes after endoscopic submucosal dissection.

BACKGROUND: Gastric cancer is a common malignant tumor of the digestive tract, and endoscopic submucosal dissection (ESD) is the preferred treatment for early-stage gastric cancer. The analysis of the epidemiological characteristics of gastric mucosal tumors with different differentiation degrees and the influencing factors of long-term ESD efficacy may have certain significance for revealing the development of gastric cancer and ESD. AIM: To analyze the features of gastric mucosal tumors at different differentiation levels, and to explore the prognostic factors of ESD. METHODS: We retrospectively studied 301 lesions in 285 patients at The Second Affiliated Hospital of Xi'an Jiaotong University from 2014 to 2021, according to the latest Japanese guidelines (sixth edition), and divided them into low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), and differentiated and undifferentiated early carcinoma. They are followed up by endoscopy, chest and abdominal computed tomography at 3, 6 and 12 months after ESD. We compared clinicopathologic characteristics, ESD efficacy, and complications with different degrees of differentiation, and analyzed the related factors associated with ESD. RESULTS: HGIN and differentiated carcinoma patients were significantly older compared with LGIN patients (P < 0.001) and accounted for more 0-IIc (P < 0.001), atrophic gastritis was common (P < 0.001), and irregular microvascular patterns (IMVPs) and demarcation lines (DLs) were more obvious (P < 0.001). There was more infiltration in the undifferentiated carcinoma tissue (P < 0.001), more abnormal folds and poorer mucosal peristalsis (P < 0.001), and more obvious IMVPs, irregular microsurface patterns and DLs (P < 0.05) than in the LGIN and HGIN tissues. The disease-free survival rates at 2, 5, and 8 years after ESD were 95.0%, 90.1%, and 86.9%, respectively. Undifferentiated lesions (HR 5.066), white moss (HR 7.187), incomplete resection (HR 3.658), and multiple primary cancers (HR 2.462) were significantly associated with poor prognosis. CONCLUSION: Differentiations of gastric mucosal tumors have different epidemiological and endoscopic characteristics, which are closely related to the safety and efficacy of ESD.

Clinicopathologic and endoscopic characteristics of ten patients with gastric hamartomatous inverted polyp: a single center case series.

BACKGROUND: Gastric hamartomatous inverted polyps (GHIPs) are not well characterized and remain diagnostically challenging due to rarity. Therefore, this study aims to investigate the clinicopathologic and endoscopic characteristics of patients with GHIP. METHODS: We retrospectively reviewed clinicopathologic and endoscopic features of ten patients with GHIP who were admitted to Beijing Friendship Hospital from March 2013 to July 2022. All patients were treated successfully by endoscopic resection. RESULTS: GHIPs were usually asymptomatic and found incidentally during gastroscopic examination. They may be sessile or pedunculated, with diffuse or local surface redness or erosion. On endoscopic ultrasonography, the sessile submucosal tumor-type GHIP demonstrated a heterogeneous lesion with cystic areas in the third layer of the gastric wall. Histologically, GHIPs were characterized by a submucosal inverted proliferation of cystically dilated hyperplastic gastric glands accompanied by a branching proliferation of smooth muscle bundles. Inflammatory cells infiltration was observed in the stroma, whereas only one patient was complicated with glandular low-grade dysplasia. Assessment of the surrounding mucosa demonstrated that six patients (60%) had atrophic gastritis or Helicobacter pylori-associated gastritis, and four patients (40%) had non-specific gastritis. Endoscopic resection was safe and effective. CONCLUSIONS: GHIPs often arise from the background of abnormal mucosa, such as atrophic or H.pylori-associated gastritis. We make the hypothesis that acquired inflammation might lead to the development of GHIPs. We recommend to make a full assessment of the background mucosa and H. pylori infection status for evaluation of underlying gastric mucosal abnormalities, which may be the preneoplastic condition of the stomach.

Exploring non-curative endoscopic submucosal dissection: Current treatment optimization and future indication expansion.

The increasing popularity of endoscopic submucosal dissection (ESD) as a treatment for early gastric cancer has highlighted the importance of quality assessment in achieving curative resections. This article emphasizes the significance of evaluating ESD quality, not only for curative cases but also for non-curative ones. Postoperative assessment relies on the endoscopic curability (eCura) classification, but management strategies for eCuraC-1 tumour with a positive horizontal margin are unclear. Current research primarily focuses on comparing additional surgical procedures in high-risk patients, while studies specifically targeting eCuraC-1 patients are limited. Exploring management strategies and follow-up outcomes for such cases could provide valuable insights. Furthermore, the application of molecular imaging using near-infrared fluorescent tracers holds promise for precise tumour diagnosis and navigation, potentially impacting the management of early-stage gastric cancer patients. Advancing research in these areas is essential for improving the overall efficacy of endoscopic techniques and refining treatment indications.

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.

Computer-aided diagnosis in real-time endoscopy for all stages of gastric carcinogenesis: Development and validation study.

OBJECTIVE: Using endoscopic images, we have previously developed computer-aided diagnosis models to predict the histopathology of gastric neoplasms. However, no model that categorizes every stage of gastric carcinogenesis has been published. In this study, a deep-learning-based diagnosis model was developed and validated to automatically classify all stages of gastric carcinogenesis, including atrophy and intestinal metaplasia, in endoscopy images. DESIGN: A total of 18,701 endoscopic images were collected retrospectively and randomly divided into train, validation, and internal-test datasets in an 8:1:1 ratio. The primary outcome was lesion-classification accuracy in six categories: normal/atrophy/intestinal metaplasia/dysplasia/early /advanced gastric cancer. External-validation of performance in the established model used 1427 novel images from other institutions that were not used in training, validation, or internal-tests. RESULTS: The internal-test lesion-classification accuracy was 91.2% (95% confidence interval: 89.9%-92.5%). For performance validation, the established model achieved an accuracy of 82.3% (80.3%-84.3%). The external-test per-class receiver operating characteristic in the diagnosis of atrophy and intestinal metaplasia was 93.4 ± 0% and 91.3 ± 0%, respectively. CONCLUSIONS: The established model demonstrated high performance in the diagnosis of preneoplastic lesions (atrophy and intestinal metaplasia) as well as gastric neoplasms.

Endoscopic Kyoto and Kimura-Takemoto Classifications Are Comparable in Predicting High-Risk Gastric Precancerous Lesions.

INTRODUCTION: Severe and extensive gastric atrophy, extensive or incomplete gastric intestinal metaplasia, and gastric dysplasia are considered high-risk gastric precancerous lesions (HGPLs). Endoscopic findings based on the endoscopic Kyoto classification (EKC) and the Kimura-Takemoto classification (KTC) have been reported to be significantly associated with HGPLs. This study aimed to compare these two classifications in predicting active Helicobacter pylori (H. pylori) infection and HGPLs. METHODS: This is a cross-sectional study conducted on naïve dyspeptic patients who underwent upper gastrointestinal endoscopy at a tertiary hospital. Endoscopic findings were scored according to the EKC and KTC. Mapping biopsies were taken, and H. pylori infection was determined using a locally validated rapid urease test and histology. The performance of EKC was compared with that of KTC using the area under the receiver operating characteristic curve (AUC) in predicting active H. pylori infection and HGPLs. RESULTS: There were 292 patients with a median age of 46 and a male-to-female ratio of 1:1. The rates of active H. pylori infection and HGPLs were 61.3% and 14.0%, respectively. The EKC was better than the KTC in predicting active H. pylori infection (AUC: 0.771 vs. 0.658, respectively; p < 0.001). However, these two classifications had comparable performance in predicting HGPLs (AUC: 0.792 vs. 0.791, respectively; p = 0.956). CONCLUSION: Compared to EKC, KTC is inferior in predicting active H. pylori infection but has comparable performance in predicting HGPLs.

L-Menthol for Color Difference Change Between Early Gastric Cancer and Surrounding Mucosa: A Prospective Study.

BACKGROUND: L-Menthol sprayed on early gastric cancer (EGC) has been reported to improve the visibility of the lesion. However, its impact when used in combination with novel image-enhanced endoscopy has not been investigated. AIM: This study aimed to evaluate the visual effect of spraying L-menthol on EGC under linked color imaging (LCI). METHODS: This open-label, single-arm, prospective study investigated the color difference between EGC and the surrounding mucosa (ΔEG) before and after spraying L-menthol. The primary endpoint was the percentage of lesions with ΔEG ≥ 5 on LCI. The percentage of lesions with ΔEG ≥ 5 on white light imaging (WLI) and blue laser imaging (BLI), ΔEG before and after spraying L-menthol, and percentage of lesions with increased ΔEG after spraying L-menthol constituted the secondary endpoints. RESULTS: Sixty patients were included in the final analysis. 100% lesions had ΔEG ≥ 5, both before and after spraying L-menthol on LCI, with similar results observed in WLI as well as BLI. The median ΔEG on LCI, WLI, and BLI increased after spraying L-menthol (LCI: 16.9 vs. 21.5, p < 0.01; WLI: 10.4 vs. 13.4, p < 0.01; BLI; 12.1 vs. 15.7, before and after, respectively, p < 0.01); and LCI demonstrated the highest percentage of lesions with increased ΔEG (LCI, WLI, and BLI: 98.3%, 81.7%, and 76.7%, respectively, p < 0.01). CONCLUSION: Although spraying L-menthol did not improve the visibility of EGC under LCI observation, a significant increase in ΔEG was observed in LCI (jRCTs 021200027).

Effect of Helicobacter pylori eradication evaluated using magnifying endoscopy with narrow-band imaging in mixed-type early gastric Cancer.

BACKGROUND: The effect of Helicobacter pylori (H.pylori) eradication therapy on mixed-histological-type gastric cancer remains unclear. This study aimed to clarify the effect of H. pylori eradication therapy on mixed-histological-type early gastric cancer using endoscopic and histological findings. METHODS: This single-center, retrospective study included patients with mixed-histological-type gastric cancer who underwent endoscopic submucosal dissection at the Cancer Institute Hospital. We compared detailed magnifying endoscopy with narrow-band imaging findings between eradicated and non-eradicated groups of patients with differentiated-type- and undifferentiated-type-predominant cancers. Subsequently, we performed histological evaluations of the non-cancerous epithelium covering differentiated-type components. RESULTS: A total of 124 patients with mixed-type early gastric cancer were enrolled (eradicated group: 62 differentiated-type-predominant cancer patients and 8 undifferentiated-type-predominant cancer patients; non-eradication group: 40 differentiated-type-predominant cancer patients and 14 undifferentiated-type-predominant cancer patients). Regarding differentiated-type-predominant cancer, differentiated-type findings were detected in all patients in eradicated and non-eradicated groups. The difference in the detection rate of undifferentiated-type findings between both groups was not significant in differentiated-type-predominant cancer patients. In differentiated-type-predominant cancers, the percentage of non-cancerous epithelium covering differentiated-type components was higher in the eradicated group than in the non-eradicated group (median: 60% vs. 40%, p < 0.001). CONCLUSIONS: Although the pathological findings of differentiated-type-predominant cancer were affected by H. pylori eradication, eradication did not affect the diagnosis of differentiated-type-predominant early gastric cancer using magnifying endoscopy with narrow-band imaging. ME-NBI is useful for the early detection of D-MIX EGCs and diagnosis of histological types during endoscopy, regardless of whether H. pylori eradication therapy has been administered.

Coexistence of early gastric cancer and benign submucosal lesions mimic invasive cancer: a retrospective multicenter experience.

OBJECTIVE: To present a study to identify the characteristics of coexisting early gastric cancer (EGC) and benign submucosal lesions, with the aim of reducing the adverse consequences of overdiagnosis and overtreatment. METHODS: In this retrospective study, we searched the endoscopic databases of three tertiary centers. We screened of patients suspected of early gastric cancer submucosal infiltration by conventional endoscopy and ultimately selected for endoscopic submucosal dissection treatment after endoscopic ultrasonography and magnifying endoscopy with narrow-band imaging examination. Patients with coexisting EGC and benign submucosal lesions in histological sections were included. Clinical data and endoscopic images were reviewed. To evaluate the precision of endoscopists' diagnoses for this type of lesion, eight endoscopists with different experiences were recruited to judge the infiltration depth of these lesions and analyze the accuracy rate. RESULTS: We screened 520 patients and retrospectively identified 18 EGC patients with an invasive cancer-like morphology. The most common lesion site was the cardia (12/18, 66.67%). The coexisting submucosal lesions could be divided into solid (5/18, 27.78%) and cystic (13/18, 72.22%). The most common type of submucosal lesion was gastritis cystica profunda (12/18, 66.67%), whereas leiomyoma was the predominant submucosal solid lesion (3/18, 16.67%). Ten (55.56%) patients < underwent endoscopic ultrasonography; submucosal lesions were definitively diagnosed in 6 patients (60.00%). The accuracy of judgement of the infiltration depth was significantly lower in cases of coexistence of EGC with benign submucosal lesions (EGC-SML) than in EGC (38.50% versus 65.60%, P = 0.0167). The rate of over-diagnosis was significantly higher within the EGC-SML group compared to the EGC group (59.17% versus 10.83%, P < 0.0001). CONCLUSIONS: We should be aware of the coexistence of EGC and benign submucosal lesions, the most common of which is early cardiac-differentiated cancer with gastritis cystica profunda.

99mTc-pertechnetate thyroid static scintigraphy unexpectedly revealed ectopic gastric mucosa of upper esophagus.

Technetium-99m (99mTc)-pertechnetate can be taken up by both gastric mucosa and thyroid tissue. Ectopic gastric mucosa of upper esophagus found in thyroid scintigraphy is rare. We reported a 31-year-old woman who underwent 99mTc-pertechnetate thyroid static scintigraphy for abnormal ultrasound findings. A focal uptake lesion was found in her upper chest. Single photon emission computed tomography/computed tomography (SPECT/CT) imaging showed increased uptake in multiple sites of the upper esophagus without significant thickening. Eventually, gastroscopic findings revealed multiple ectopic gastric mucosa of upper esophagus.

[Features of the upper gastrointestinal tract mucous membrane state in patients with atherosclerosis of the mesenteric arteries].

AIM: To evaluate the clinical and endoscopic features of diseases of the upper gastrointestinal tract (GIT) in patients with atherosclerosis of the mesenteric arteries (MA). MATERIALS AND METHODS: The study included 48 patients with atherosclerosis of MA and 43 patients without atherosclerosis of MA, who were hospitalized in the department of vascular surgery of the Chelyabinsk Regional Clinical Hospital in the period from 2019 to 2021. All patients underwent multispiral computed tomoangiography of the visceral and lower limb arteries, esophagogastroduodenoscopy. RESULTS: Assessment of lesions of the upper gastrointestinal tract revealed a higher incidence of erosive and ulcerative gastroduodenopathies among patients with atherosclerosis of MA (60.4%), compared with patients without atherosclerosis MA (39.5%); p=0.047. Signs of severe atrophy according to the data of histological examination were statistically significantly more frequent among patients with atherosclerosis of MA (29.2 and 11.6%; p=0.031). According to the results of logistic regression, the following predictors of erosions and ulcers of the upper gastrointestinal tract were revealed: the severity of stenosis of the superior mesenteric artery (SMA) is more than 35%, the body mass index (BMI) is less than 25.9 and the total score on the HADS scale is more than 6.5 points for depression (p=0.008). CONCLUSION: Erosive-ulcerative gastroduodenopathies and atrophy of the gastric mucosa are significantly more common in the group of patients with MA atherosclerosis. The main risk factors for erosions and ulcers of the upper gastrointestinal tract in patients with MA atherosclerosis are: the severity of SMA stenosis is more than 35%, a decrease in BMI is less than 25.9 and an increase in the HADS score is more than 6.5 points.

Red dichromatic imaging improves visibility of bleeding during gastric endoscopic submucosal dissection.

Bleeding frequently occurs during gastric endoscopic submucosal dissection (ESD) and bleeding points are sometimes difficult to detect. Red dichromatic imaging (RDI) was recently developed to improve the visibility of bleeding. Our study aimed at examining the efficacy of RDI in improving the visibility of bleeding during gastric ESD. We retrospectively evaluated the visibility score and color difference of bleeding spot during gastric ESD during September 2020-January 2021. The visibility score was evaluated as four numeric values by operators, and the color difference between the bleeding spot and surroundings was evaluated using RDI and white light imaging (WLI). A further analysis to evaluate bleeding characteristics was performed to evaluate the possible beneficial effects of RDI. Twenty patients with a total of 85 bleedings were analyzed. The mean visibility score in RDI was significantly higher than that in WLI (3.69 ± 0.60 vs 3.20 ± 0.84, p < 0.01). The color difference with RDI was also significantly higher than that with WLI (19.51 ± 15.18 vs 14.80 ± 7.41, p < 0.01). Furthermore, in the bleedings with a higher visibility score in RDI, the color difference in RDI was significantly higher than that in WLI (23.99 ± 19.29 vs 14.33 ± 7.08, p < 0.01). The multivariate analysis of visibility scores revealed that submergence of bleeding points was independently associated with the superiority of RDI (odds ratio 10.35, 95% confidence interval: 2.76-38.81, p < 0.01). Our study demonstrates that RDI can improve the visibility of bleeding during gastric ESD.

Mucosal patterns change after Helicobacter pylori eradication: Evaluation using blue laser imaging in patients with atrophic gastritis.

BACKGROUND: Mucosal patterns (MPs) observed on blue laser imaging in patients with atrophic gastritis can be classified as spotty, cracked, and mottled. Furthermore, we hypothesized that the spotty pattern may change to the cracked pattern after Helicobacter pylori (H. pylori) eradication. AIM: To further substantiate and comprehensively investigate MP changes after H. pylori eradication in a larger number of patients. METHODS: We included 768 patients who were diagnosed with atrophic gastritis with evaluable MP using upper gastrointestinal endoscopy at the Nishikawa Gas-trointestinal Clinic, Japan. Among them, 325 patients were H. pylori-positive, and of them, 101 patients who underwent upper gastrointestinal endoscopy before and after H. pylori eradication were evaluated for post-eradication MP changes. The patients' MPs were interpreted by three experienced endoscopists who were blinded to their clinical features. RESULTS: Among 76 patients with the spotty pattern before or after H. pylori eradication, the pattern disappeared or decreased in 67 patients [88.2%, 95% confidence interval (CI): 79.0%-93.6%), appeared or increased in 8 patients (10.5%, 95%CI: 5.4%-19.4%), and showed no change in 1 patient (1.3%, 95%CI: 0.2%-7.1%). In 90 patients with the cracked pattern before or after H. pylori eradication, the pattern disappeared or decreased in 7 patients (7.8%, 95%CI: 3.8%-15.2%), appeared or increased in 79 patients (87.8%, 95%CI: 79.4%-93.0%), and showed no change in 4 patients (4.4%, 95%CI: 1.7%-10.9%). In 70 patients with the mottled pattern before or after H. pylori eradication, the pattern disappeared or decreased in 28 patients (40.0%, 95%CI: 29.3%-51.7%), appeared or increased in 35 patients (50.0%, 95%CI: 38.6%-61.4%), and showed no change in 7 patients (10.0%, 95%CI: 4.9%-19.2%). CONCLUSION: After H. pylori eradication, MPs changed from spotty to cracked in most patients, which may help endoscopists easily and precisely evaluate H. pylori-related gastritis status.

Clinical Usefulness of Linked Color Imaging for Detection and Characterization of UndifferentiatedType Early Gastric Cancer.

BACKGROUND: Linked color imaging is based on the bioluminescent imaging technique, which enhances differences in mucosal color allowing for contrast-based detection of lesions. There have been reports which have investigated the usefulness of linked color imaging for assessing color values in endoscopy for early gastric cancer cases. However, these primarily focused on differentiated early gastric cancer. This study aimed to assess the efficacy of linked color imaging in analyzing the color differences between cancerous and noncancerous areas in undifferentiated-type early gastric cancer patients compared with conventional white light imaging. METHODS: Forty-six patients were prospectively enrolled with undifferentiated-type early gastric cancer from 3 academic hospitals. All lesions were observed first by white light imaging followed by linked color imaging. An additional biopsy was taken from the surrounding mucosa to check for intestinal metaplasia, and test for Helicobacter pylori was performed. Color difference was measured in accordance with the International Commission on Illumination details. RESULTS: The color difference value with linked color imaging was significantly higher, being more than twice that of white light imaging (26.82 ± 14.18 and 12.60 ± 6.42, P < .001), and this difference appeared to be similar in cases of accompanying Helicobacter pylori infection or intestinal metaplasia. In the subgroup analysis, color difference of poorly differentiated adenocarcinoma was notable in linked color imaging compared to white light imaging. Conversely, no statistically significant finding was present in signet ring cell carcinoma or mixed-type histology. CONCLUSION: Linked color imaging provides a significantly greater color difference between cancerous lesions and background noncancerous mucosa in undifferentiated-type early gastric cancer. Moreover, linked color imaging may differentiate between pathologic subgroups of undifferentiated-type early gastric cancer possibly due to characteristic cellular growth pattern.

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.

Gastric Mucosal Viability Assessment Using 99mTcO4 in a Case of Pure Esophageal Atresia After Isoperistaltic Gastric Tube Replacement.

ABSTRACT: Gastric surface mucosal cells are responsible for the uptake and secretion of 99mTcO4, a feature that has been used in imaging heterotopic gastric mucosa. We used the same principle to look for gastric mucosal viability in this case of pure esophageal atresia admitted for cervical stomal closure after a previous isoperistaltic gastric tube (IGT) replacement procedure. 99mTcO4 scintigraphy was done after encountering a failure to maneuver the esophagoscope through the IGT. The study was helpful in assessing the loss of gastric mucosal viability in an intervening segment of the IGT.