All-in-one sphincterotome with high rotation performance and freely bendable blade for endoscopic sphincterotomy in patients with surgically altered anatomy (a case series with video).

A new type of sphincterotome released to the market recently has high rotation performance and a freely bendable blade. It is devised to be singly capable of accommodating not only normal anatomy but also cases with surgically altered anatomy. This study was undertaken for clinical evaluation of the usefulness of this new sphincterotome. Eight cases in a reconstructed intestine for which cannulation or endoscopic sphincterotomy (EST) had been performed were extracted from 32 cases for which endoscopic retrograde cholangiopancreatography-related procedures were performed using the sphincterotome developed during November 2023 through February 2024. The cases were investigated retrospectively. Among these, EST was applied to six cases. Cannulation was performed using the developed sphincterotome in the native papilla in four cases. The primary endpoints were the success rate of cannulation in surgically altered anatomy and the success rate of EST. Secondary endpoints were complications and usability for operators. Usability for operators was evaluated by questionnaire for several items on a 5-point scale. EST was conducted successfully in all six cases subjected to EST. Mild hemorrhage was observed in one case (17%) as an adverse event after EST. Deep cannulation to the native papilla with the developed sphincterotome was conducted successfully in three cases (75.0%). Evaluation results by operators were 4.4 ± 0.55 for rotation performance, 4.00 ± 0.63 for incision performance, 4.29 ± 0.49 for deep cannulation performance, and 4.07 ± 0.19 for overall evaluation. In conclusion, this developed sphincterotome might be very useful for EST and cannulation in cases with surgically altered anatomy.

Endoscopic ultrasound-guided vascular interventions.

With the recent development of interventional endoscopic ultrasound (EUS), EUS-guided vascular interventions have seen increased clinical and research focus. This modality can be used to diagnose portal hypertension and treat portal hypertension-related gastrointestinal varices and refractory gastrointestinal hemorrhage, including pseudoaneurysm. The vascular embolic materials used for treatment include tissue adhesives (cyanoacrylates), sclerosants, thrombin, and vascular embolic coils, all of which are associated with favorable results. The feasibility of EUS-guided procedures, including portal vein stenting and portosystemic shunt formation conventionally performed percutaneously and transvenously, has also been demonstrated, albeit in animal studies. As EUS-guided vascular intervention is a technique that may receive significant attention in the future, we provide a thorough review of the current evidence for its use.

Association Between Early Mobilization and Functional Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage: A Multicenter Retrospective Propensity Score-Matched Study.

BACKGROUND: Early mobilization has been shown to promote functional recovery and prevent complications in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, the efficacy of early mobilization in patients with aSAH remains unclear. This study aimed to investigate the association between early mobilization and functional outcomes in patients with aSAH. METHODS: This multicenter retrospective study was conducted in Japan and included patients with aSAH who received physical therapy with or without occupational therapy from April 2014 to March 2019. The primary outcome was the modified Rankin Scale (mRS) score, with a favorable functional outcome defined as an mRS score of 0-2 and an unfavorable outcome with an mRS score of 3-5. Patients initiating walking training within 14 days of aSAH onset were classified into the early mobilization group, whereas those initiating training after 14 days were classified into the delayed mobilization group. Propensity score matching analysis was performed to assess the association between early mobilization and favorable outcomes. RESULTS: A total of 718 patients were screened, and 450 eligible patients were identified. Before matching, 229 patients (50.9%) were in the early mobilization group and 221 (49.1%) were in the delayed mobilization group. After matching, each group consisted of 122 patients, and the early mobilization group exhibited a higher proportion of favorable outcomes than did the delayed mobilization group (81.1% vs. 52.5%, risk difference 28.7%, 95% confidence interval 17.4-39.9, p < 0.001). CONCLUSIONS: This multicenter retrospective study suggests that initiating walking training within 14 days of aSAH onset is associated with favorable outcomes.

Investigating COVID-19 Pandemic Effects on Acute Pancreatitis Development-From the Perspective of Alcohol Sales (Consumption) in a Japanese Regional Hospital.

[Aim and Background] People's lifestyles changed considerably due to the coronavirus disease 2019 (COVID-19) pandemic. The number of patients with acute pancreatitis (AP) can be expected to decrease as alcohol consumption decreases. This study was conducted to assess COVID-19 pandemic effects on AP patients in a Japanese regional hospital. [Methods] Based on the first and second states of emergency declarations in Tochigi Prefecture, the survey periods were set as follows: period A, 16 April-14 May; period B, 15 May-13 January; period C, 14 January-7 February; and period D, 8 February-15 April. Using data acquired in 2017, 2018, 2019, and 2020, we retrospectively reviewed the number of patients admitted to our hospital with a diagnosis of AP, and their clinical characteristics. [Results] According to a National Tax Agency survey, the average alcohol sales per adult in Tochigi Prefecture were 71.3 L in 2017 before the pandemic, and 64.0 L in 2021 under the pandemic. The number of AP patients in 2020 was 38% lower than in 2017. Comparing 2017 with 2020, the number of alcoholic AP patients was lower in 2020 (p = 0.007). [Conclusions] The findings suggest that COVID-19-pandemic-related lifestyle changes contributed to the decrease in AP patients.

Proposal and Validation of New Diagnostic Criteria for Diagnostic Weights of Endoultrasonographic Findings for Early Chronic Pancreatitis.

[Background and study aim] A commonly applied method for diagnosing chronic pancreatitis (CP) uses endoscopic ultrasonography (EUS), assigning weights to each EUS diagnostic finding. It is the Rosemont classification (RC). In 2019, to improve EUS diagnostic specificity, Japanese diagnostic criteria for early chronic pancreatitis (ECP) were revised. Nevertheless, the criteria use no weighting of EUS diagnostic findings, as the RC does. This study was undertaken to propose diagnostic criteria that would weight each EUS finding of ECP and that would be more specific than the RC. [Methods] By EUS of the pancreas, 773 patients underwent detailed observation from January 2018 to March 2019 at our institution. An expert finalized all cases when patients were diagnosed. Using data from the medical records, 97 consecutive patients with EUS diagnostic findings of ECP based on the Japanese diagnostic criteria of ECP2009 (JDCECP2009) were selected. The definition under the RC of "Indeterminate for CP" was equivalent to ECP. Each case was diagnosed using (1) JDCECP2009 and (2) the Japanese diagnostic criteria of ECP2019 (JDCECP2019). Moreover, the four diagnostic EUS findings in JDCECP2019 were applied to the RC, weighted (modified-JDCECP2019), and subsequently compared with the earlier diagnostic criteria. As Modified-JDCECP2019, we suggested (3) RC-A-the current four items scored related to the RC, and (4) RC-B-the five items scored by dividing lobularity with and without honeycombing. [Results] Diagnoses produced based on each criterion were normal: ECP = (1) 20:77, (2) 46:51, (3) 52:42, and (4) 60:35. [Conclusions] Modified-JDCECP2019 may provide EUS diagnoses for ECP with higher specificity.

Menstrual Abnormalities in Female International Students in Japan: Changes during Pre-Arrival, Difficult, and Current Periods.

The number of Japan's international students has rapidly increased in the last decade. This study examines the relationship between menstrual abnormalities in cycle and symptoms, stress level, and lifestyle of female international students in Japan across three time periods, namely pre-arrival, difficult, and current time periods. A cross-sectional design was employed, and data were collected through a self-administered questionnaire, including the menstrual distress questionnaire (MDQ), between December 2022 and February 2023. The questionnaire was distributed to 56 female international students from two universities in Japan, and a total of 29 valid responses were collected. We found varying menstrual cycle abnormalities and severity of menstrual symptoms across three time periods, with the difficult period after arrival in Japan displaying the highest symptom severity. Higher stress levels were significantly associated with more severe menstrual symptoms. Lifestyle habits such as alcohol consumption were also linked to menstrual symptoms. The current study emphasizes the importance of providing menstrual education, support, and resources to address international students' unique challenges in managing their menstrual health while studying abroad. By promoting awareness, education, and access to healthcare services, universities may contribute to international students' well-being and academic success.

Guide Wire Selection (Straight vs. Angled) in Endoscopic Retrograde Cholangiopancreatography Using a Normal Contrast Catheter Performed by a Trainee: A Single-Center Prospective Randomized Controlled Cross-Over Study.

INTRODUCTION: Wire-guided cannulation (WGC) during endoscopic retrograde cholangiopancreatography (ERCP) is a selective biliary cannulation technique aimed at improving the successful selective biliary cannulation rate and reducing the rate of post-ERCP pancreatitis (PEP) incidence. This study aimed to evaluate the effectiveness of angled-tip guidewires (AGW) vs. straight-tip guidewires (SGW) for biliary cannulation via WGC by a trainee. METHODS: We conducted a prospective, single-center, open-labeled, randomized, and controlled trial. Fifty-seven patients were enrolled in this study and assigned randomly to two groups (Group A to S and Group S to A). In this study, we started selective biliary cannulation via WGC with an AGW or an SGW for 7 min. If cannulation was unsuccessful, the other guidewire was used, and cannulation was continued for another 7 min (cross-over method). RESULTS: The selective biliary cannulation success rate over 14 min was significantly higher with an AGW compared with an SGW over 14 min (57.8% vs. 34.3%, p = 0.04) and for the second 7-min segment (36.4% vs. 0%, p = 0.04). No significant difference was found for adverse events such as pancreatitis between the two guidewires. CONCLUSIONS: Our results suggest that an AGW is recommended for WGC performed by a trainee.

A case in which the tip of a plastic stent placed to prevent recurrence of walled-off necrosis penetrated the bile duct and formed a stent-stone complex.

A woman in her 60s underwent endoscopic sphincterotomy for choledocholithiasis. Unfortunately, post-endoscopic retrograde cholangiopancreatography pancreatitis occurred. In addition, huge walled-off necrosis (WON) appeared as a late complication. For the infected WON, endoscopic ultrasound-guided fistuloplasty and endoscopic necrosectomy were performed, and a double pigtail plastic stent (PS) (7Fr, 7 cm) was placed to prevent a recurrence. Plain computed tomography conducted two years later showed that the stent implanted for WON had deviated. The distal end of the stent was found to have migrated into the bile duct. In addition, common bile duct stones with stents as nuclei were observed. Upon performing endoscopic retrograde cholangiography, it was revealed that the stent tip perforated the distal bile duct just above the papilla. After removal of the stent using grasping forceps, we made an incision between the duodenal - bile duct fistula and bile duct orifice using a sphincterotome. Then, the stone was removed by a balloon catheter. Although such late adverse events are rare occurrences, placement of long-term PS after treatment of WON should be followed up regularly with imaging examination, and if there is no recurrence for several months, removal of the PS at that point may be considered.

Diagnosing chronic pancreatitis by endoscopic ultrasound assessing the association between ultrasound and pathological findings: A narrative review.

Endoscopic ultrasound (EUS) is widely recognized for its non-invasiveness and for its usefulness in chronic pancreatitis (CP) diagnosis, including early CP. Although it is desirable to obtain a definitive diagnosis of CP by tissue sampling with EUS-guided fine needle aspiration, histopathological changes in CP are heterogeneous in terms of the extent and the distribution of lesions. Therefore, histopathological diagnosis of appropriate tissue sampling by EUS-fine needle aspiration is expected to be difficult. Furthermore, it is virtually impossible to match EUS images with pathological sections, making direct contrast between EUS findings and pathology difficult. This narrative review presents a discussion of the diagnosis of CP/early CP by EUS, particularly assessing the association between ultrasound and pathological findings. Recently, the histological corroboration and correlation of EUS findings related to CP have been clarified by surgical specimens, including those obtained from animal studies. Furthermore, remarkable advances have occurred in the objective and quantitative diagnosis of pancreatic fibrosis by EUS-elastography. Future technological advances in EUS are expected to improve the accuracy of diagnosis of pancreatic fibrosis at earlier stages.

Size reduction of gastric fundic gland polyposis by de-escalation of acid-suppressive therapy.

The patient, a 73-year-old woman, had been taking acid-suppressive therapy for refractory reflux esophagitis for 10 years. A potassium-competitive acid blocker was administered to strengthen acid-suppressive therapy for worsening symptoms of gastroesophageal reflux disease. Esophagogastroduodenoscopy showed an increase in the number and size of fundic gland polyposis (FGPs). When acid-suppressive therapy was changed from potassium-competitive acid blocker to proton pump inhibitor, the FGPs showed reduced size 1 year later. Furthermore, when acid-suppressive therapy was changed from proton pump inhibitor to histamine-2 receptor antagonist, FGPs were even smaller after 1 and 2 years. The patient, who had no flare-up of gastroesophageal reflux disease symptoms, continues to be treated medically with histamine-2 receptor antagonist. This case report describes changes in endoscopic findings of a patient with FGPs caused by acid-suppressive therapy for refractory gastroesophageal reflux disease.

Usefulness of Adding Maspin Staining to p53 Staining for EUS-FNA Specimens of Pancreatic Ductal Adenocarcinoma.

Background: Endoscopic ultrasound-guided puncture aspiration biopsy (EUS-FNA) of pancreatic ductal adenocarcinoma (PDAC) is highly diagnostic, but it is difficult to distinguish from benign disease. Our objective was to determine the usefulness of maspin staining, in addition to conventional p53 staining, in the diagnosis of PDAC by EUS-FNA. Methods: Of the patients who underwent EUS-FNA and were diagnosed with PDAC, we retrospectively identified 90 cases in which both maspin and p53 staining were performed. In addition, we identified 28 cases of benign pancreatic disease diagnosed using EUS-FNA and these were selected as a control group. For analysis of EUS-FNA specimens, Cohen's Kappa (κ) coefficient and the prevalence and bias adjusted Kappa statistic (PABAK) were applied to assess the significance of sensitivity and specificity, comparing p53, maspin, p53+maspin. Results: The sensitivity and specificity of p53 staining were 48.9% and 100%. The κ coefficient was 0.31 (95%CI 0.18−0.44) (p < 0.01) and the PABAK coefficient was 0.22 (95%CI 0.03−0.40). The results for maspin staining were 88.9% and 92.9%. The κ coefficient was 0.72 (95%CI 0.54−0.90) (p < 0.01) and the PABAK coefficient was 0.78 (95%CI 0.64−0.88). The results for the combination of maspin and p53 staining were 94.4% and 92.2%. The κ coefficient was 0.82 (95%CI 0.64−1.00) (p < 0.01) and the PABAK coefficient was 0.86 (95%CI 0.74−0.94). Conclusion: Adding maspin staining to p53 staining showed high sensitivity and specificity. Our results demonstrated the usefulness of their combined use that might contribute to the improvement of tissue diagnostic performance of PDAC by EUS-FNA.

Initiating Mobilization Is Not Associated with Symptomatic Cerebral Vasospasm in Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Multicenter Case-control Study.

OBJECTIVE: The study aim was to investigate the association between initiating mobilization within 7 days after onset and symptomatic cerebral vasospasm (SCV) in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: This was a retrospective multicenter case-control study in Japan. Patients with a diagnosis of aSAH who underwent physical therapy with/without occupational therapy were included and categorized into 2 groups according to the presence or absence of SCV. Initiating mobilization was defined as sitting on the bed edge (at least once, with/without assist, regardless of duration) within 7 days after aSAH onset. Cox proportional hazards regression analysis was performed to evaluate the association between initiating mobilization within 7 days after onset and SCV. RESULTS: The analysis included 510 patients. Among all included patients, 57 (11.2%) patients had SCV. In the univariate Cox proportional hazards regression analysis, initiating of mobilization was not associated with SCV (hazard ratio [HR] = 0.78; 95% confidence interval [CI] = 0.45-1.32). In the multivariate analysis, only the modified Fisher scale was significantly associated with SCV (HR = 26.23; 95% CI = 1.21-571.0). CONCLUSION: Initiating mobilization within 7 days after aSAH onset was not associated with SCV in patients with aSAH.

Antibacterial and Antifungal Activities of PMMAs Implanted Fluorine and/or Silver Ions by Plasma-Based Ion Implantation with Argon.

The purpose of this study was to examine the anti-oral microorganism effects of fluorine and/or silver ions implanted into acrylic resin (PMMA) using plasma-based ion implantation (PBII) with argon gas. The experimental PMMA specimens were implanted with F and Ag ions alone or simultaneously by the PBII method using Ar or Ar/F2 gases and Ag mesh. The surface characteristics were evaluated by X-ray photoelectron spectroscopy (XPS), contact angle measurements, and atomic force microscopy (AFM). Moreover, the antibacterial activity against Streptococcus mutans (S. mutans) and the antifungal activity against Candida albicans (C. albicans) were examined by the adenosine-5'-triphosphate (ATP) emission luminescence method. XPS spectra of the modified specimens revealed peaks due to F in the Ar/F and the Ar/F+Ag groups, and due to Ag in the Ar+Ag and the Ar/F+Ag groups. The water contact angle increased significantly due to the implantation of Ar, F, and Ag. In the AFM observations, the surface roughness of the Ar/F and the Ar/F+Ag groups increased significantly by less than 5 nanometers. The presence of F and Ag was found to inhibit S. mutans growth in the Ar+Ag and the Ar/F+Ag groups. However, this method provided no significant antifungal activity against C. albicans.

The risks and characteristics of the delayed bleeding after endoscopic submucosal dissection for early gastric carcinoma in cases with anticoagulants.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early gastric carcinoma. Vitamin K antagonists and direct oral anticoagulants (DOAC) were reported to increase the risk of delayed bleeding after ESD. However, the evaluation of ESD cases taking anticoagulants is scarce. We analyzed the risk and characteristics of delayed bleeding after gastric ESD in patients on anticoagulants. METHODS: We performed a retrospective observational study at a single center. Consecutive patients who underwent ESD for early gastric carcinoma and took anticoagulants, including warfarin, rivaroxaban, dabigatran, apixaban, and edoxaban, between January 2012 and December 2018, were analyzed. We also calculated delayed bleeding rates for those without anticoagulants. RESULTS: Of 1855 eligible patients who underwent gastric ESDs, 143 took anticoagulants. Delayed bleeding occurred in 30 (21.0%) cases taking anticoagulants, with 15 (19.5%) cases in the DOAC group [rivaroxaban, seven cases (21.2%); dabigatran, four cases (20.0%); apixaban, four cases (23.5%); and edoxaban, zero cases (0%)] and 15 cases (22.7%) in the warfarin group. Furthermore, 43/344 (12.5%) patients taking antiplatelets and 76/1368 (5.6%) patients without antithrombic drugs experienced delayed bleeding. Multivariable logistic analysis revealed post-heart valve replacement (OR, 6.56; 95% CI, 1.75-24.7; p < .05) as a risk for delayed bleeding in warfarin-taking patients, while no statistically significant factor was found in DOAC-taking patients. CONCLUSIONS: Anticoagulants were associated with a high incidence of severe delayed bleeding. Careful attention should be paid to patients on anticoagulants after gastric ESD, especially those on warfarin after heart valve replacement.

Mechanical and Functional Properties of a Novel Apatite-Ionomer Cement for Prevention and Remineralization of Dental Caries.

Especially in pediatric dentistry, prevention by the control of initial lesions prior to cavitation is very important, and application of a pit and fissure sealant is essential to achieve this. Numerous reports have suggested that resin-based sealants are inferior to sealants based on glass-ionomer cement (GIC), because of GIC's many advantages, such as fluoride ion release properties and its good adhesion to tooth structures. However, the use of GIC is impeded due to its low flexural strength and fracture toughness. In this paper, we developed and characterized an apatite-ionomer cement (AIC) that incorporates hydroxyapatite (HAp) into the GIC; this development was aimed at not only reinforcing the flexural and compressive strength but also improving some functional properties for the creation of the material suitable for sealant. We examined the influence of differences in the compounding conditions of GIC powder, liquid, and HAp on flexural and compressive strengths, fracture toughness, fluoride ion release property, shear bond strength to bovine enamel, surface pH of setting cements, and acid buffer capability. These methods were aimed at elucidating the reaction mechanism of porous spherical-shaped HAp (HApS) in AIC. The following observations were deduced. (1) HAp can improve the mechanical strengths of AIC by strengthening the cement matrix. (2) The functional properties of AIC, such as acid buffer capability, improved by increasing the releasing amounts of various ions including fluoride ions. The novel AIC developed in this study is a clinically effective dental material for prevention and remineralization of tooth and initial carious lesion.

Increase in bone metabolic markers and circulating osteoblast-lineage cells after orthognathic surgery.

Increased mineralisation rate and bone formation after surgery or fracture is the regional acceleratory phenomenon (RAP), and its systemic impact is the systemic acceleratory phenomenon (SAP). The proportion of circulating osteoblast lineage cells, including osteocalcin-positive (OCN+) cells, in the peripheral blood is markedly higher during pubertal growth and in patients with bone fractures. This study aimed to elucidate the dynamic changes in bone metabolic activity after orthognathic surgery by longitudinal prospective observation. Peripheral venous blood samples were collected from patients who had undergone orthognathic surgery, and serum bone metabolic markers and the proportion of OCN+ cells were measured. Orthognathic surgery induces systemic dynamic changes in bone metabolic activity by targeting steps in the bone healing process and related proteins, such as surgical stress/inflammation (C-reactive protein), bone resorption (type I collagen C-telopeptide), and bone formation (alkaline phosphatase and bone-specific alkaline phosphatase). During the early post-operative period, the population of OCN+ cells significantly increased. Confocal microscopy revealed that OCN proteins were localised in the cytoplasm in Triton X-100-treated OCN+ cells. Furthermore, OCN, ALP, and COL1A1 gene expression was detected in OCN+ cells, suggesting the contribution of the local maturation of bone marrow-derived OCN+ cells at the site of bone healing.

Effects of Powdery Cellulose Nanofiber Addition on the Properties of Glass Ionomer Cement.

In this study, we aimed to evaluate the effect of the addition of powdery cellulose nanofibers (CNFs) on the mechanical properties of glass ionomer cement (GIC) without negatively affecting its chemical properties. Commercial GIC was reinforced with powdery CNFs (2-8 wt.%) and characterized in terms of flexural strength, compressive strength, diametral tensile strength, and fluoride-ion release properties. Powdery CNFs and samples subjected to flexural strength testing were observed via scanning electron microscopy. CNF incorporation was found to significantly improve the flexural, compressive, and diametral tensile strengths of GIC, and the corresponding composite was shown to contain fibrillar aggregates of nanofibers interspersed in the GIC matrix. No significant differences in fluoride-ion release properties were observed between the control GIC and the CNF-GIC composite. Thus, powdery CNFs were concluded to be a promising GIC reinforcement agent.

New endoscopic ultrasonography criteria for malignant lymphadenopathy based on inter-rater agreement.

BACKGROUND AND AIMS: Various studies have been previously conducted on the diagnosis of lymphadenopathy as benign or malignant, but the results vary. These studies did not describe the inter-rater agreement on the EUS features of lymphadenopathy. In this study, we evaluate the inter-rater agreement on EUS features and propose EUS diagnostic norms for lymphadenopathy based on inter-rater agreement. METHOD: A total of 68 lymph nodes subjected to EUS-fine needle aspiration (FNA) were reviewed by five endoscopic experts. The EUS features evaluated lymph node size, shape, border, margin, echogenicity, homogeneity, and the hilum of the lymph node. Inter-rater agreement (multi-rater kappa statics) was performed. We established new criteria using results with a high degree of inter-rater agreement from EUS features and compared them with the former criteria. RESULT: There was a moderate agreement on shape, kappa (K) = 0.44 (95% confidence interval [CI]: 0.34-0.54), and fair agreement on echogenicity, homogeneity, border, and hilum of the lymph node, K (95% CI) = 0.33 (0.17-0.38), 0.34 (0.26-0.35), 0.22 (0.21-0.31), and 0.22 (0.11-0.26), respectively. This resulted in the establishment of new EUS diagnostic criteria using shape, long axis > 20 mm and short axis > 10 mm. New criteria were superior to old criteria (area under the curve 0.82 vs 0.52, P < 0.001). CONCLUSION: EUS diagnostic criteria for lymphadenopathy based on inter-rater agreement were more accurate than old criteria. This result will be useful for the diagnosis of lymphadenopathy.

Endoscopic Mucosal Resection Performed Underwater for Nonampullary Duodenal Epithelial Tumor: Evaluation of Feasibility and Safety.

OBJECTIVES: Recently, opportunities to encounter superficial nonampullary duodenal epithelial tumor (SNADET) have increased. EMR and ESD are performed to treat SNADET. However, the rate of perforation is higher than that of other gastrointestinal lesions, regardless of which method is used. Underwater EMR (UW-EMR) is immersion treatment of SNADET, which has low risk of perforation and can remove lesions safely and completely. In the present study, we retrospectively investigated patients in whom UW-EMR was performed to evaluate the feasibility and safety of UW-EMR for the treatment of SNADET. METHODS: The primary endpoint was to evaluate the feasibility of UW-EMR for the treatment of SNADET, and secondary objective was to determine the operation's safety. RESULTS: There were 14 participants, with a total of 16 lesions, who underwent UW-EMR between August 2015 and December 2017. Histological heteromorphism revealed that seven patients had low-grade adenoma, seven had high-grade adenoma, and two had adenocarcinoma. En bloc resection was performed in 14 lesions. In two patients, nodular lesions were observed in the scar and biopsy confirmed recurrences. There were no serious adverse events including bleeding or perforation. CONCLUSIONS: UW-EMR may be a safe and effective treatment method for SNADET, if its therapeutic indication is adequately considered.