Resectability of Small Duodenal Tumors: A Randomized Controlled Trial Comparing Underwater Endoscopic Mucosal Resection and Cold Snare Polypectomy.

INTRODUCTION: Underwater endoscopic mucosal resection (UEMR) and cold snare polypectomy (CSP) are novel endoscopic procedures for superficial nonampullary duodenal epithelial tumors (SNADET). However, consensus on how to use both procedures appropriately has not been established. In this study, we evaluated treatment outcomes of both procedures, including resectability. METHODS: In this single-center randomized controlled study conducted between January 2020 and June 2022, patients with SNADET ≤12 mm were randomly allocated to UEMR and CSP groups. The primary end point was sufficient vertical R0 resection (SVR0), which was defined as R0 resection including a sufficient submucosal layer. We compared treatment outcomes including SVR0 rate between groups. RESULTS: The SVR0 rate was significantly higher in the UEMR group than in the CSP group (65.6% vs 41.5%, P = 0.01). By contrast, the R0 resection rate was not significantly different between study groups (70.3% vs 61.5%, P = 0.29). The submucosal layer thickness was significantly greater in the UEMR group than in the CSP group (median 546 [range, 309-833] µm vs 69 [0-295] µm, P < 0.01). CSP had a shorter total procedure time (median 12 [range, 8-16] min vs 1 [1-3] min, P < 0.01) and fewer total bleeding events (9.4% vs 1.5%, P = 0.06). DISCUSSION: UEMR has superior vertical resectability compared with CSP, but CSP has a shorter procedure time and fewer bleeding events. Although CSP is preferable for most small SNADET, UEMR should be selected for lesions that cannot be definitively diagnosed as mucosal low-grade neoplasias.

Novel quantitative assessment indicators for efficiency and precision of endoscopic submucosal dissection in animal training models by analyzing an electrical surgical unit.

OBJECTIVES: Although endoscopic submucosal dissection (ESD) training is important, quantitative assessments have not been established. This study aimed to explore a novel quantitative assessment system by analyzing an electrical surgical unit (ESU). METHODS: This was an ex vivo study. Step one: to identify the novel efficiency indicators, 20 endoscopists performed one ESD each, and we analyzed correlations between their resection speed and electrical status. Step two: to identify the novel precision indicators, three experts and three novices performed one ESD each, and we compared the stability of the electrical status. Step three: three novices in step two performed 19 additional ESDs, and we analyzed the learning curve using novel indicators. RESULTS: Step one: the percentage of total activation time (AT) of ESU in the procedure time (ß coefficient, 0.80; P < 0.01) and AT required for submucosal dissection (ß coefficient, -0.57; P < 0.01) were significantly correlated with the resection speed. Step two: coefficient of variation of the AT per one pulse (0.16 [range, 0.13-0.17] vs. 0.26 [range, 0.20-0.41], P = 0.049) and coefficient of variation of the peak electric power per pulse during mucosal incision (0.14 [range, 0.080-0.15] vs. 0.25 [range, 0.24-0.28], P = 0.049) were significantly lower in the experts than in the novices. Regarding the learning curve, the percentage of total AT of ESU in the procedure time and AT required for submucosal dissection had a trend of improvement. CONCLUSION: Novel indicators identified by analyzing ESU enable quantitative assessment for endoscopist's skill.

Novel perfusion system using continuous liquid-suction catheter attachment in colorectal endoscopic submucosal dissection with water pressure method (with video).

Water pressure method (WPM) is useful for colorectal endoscopic submucosal dissection (ESD), characterized not only by underwater conditions but also by active water pressure via the waterjet function. However, the extension of the colorectum by injecting excess water and contaminating the operative field by stool and bleeding have been issues. This study aimed to evaluate the feasibility of a novel perfusion system using a continuous liquid-suction catheter attachment (CLCA) in colorectal ESD with WPM. We retrospectively reviewed cases in which the perfusion system was used in colorectal ESD with WPM between August 2022 and September 2023. We evaluated clinical characteristics, treatment outcomes, volume of injection by the waterjet function, volume of suction by the endoscope and CLCA, and concentration of floating matter in the operative field over time. Thirty-one cases were enrolled. The median lesion size was 30 (range, 15-100) mm. In all cases, en bloc resection was achieved without perforation. The median injection volume was 2312 (range, 1234-13,866) g. The median suction volumes by the endoscope and CLCA were 918 (range, 141-3162) and 1147 (range, 254-11,222) g, respectively. The median concentration of floating matter in the operative field (measured in 15 cases) was 15.3 (range, 7.3-112) mg/mL when the endoscope arrived at the lesion and 8.0 (range, 3.2-16) mg/mL after endoscopically washing at the beginning of the ESD. It ranged from 7.6 to 13.4 mg/dL every 20 min during ESD. This perfusion system could prevent the extension of the lumen and maintain a good field of view in colorectal ESD with WPM.

Diagnostic Value of Adding Magnifying Chromoendoscopy to Magnifying Narrow-Band Imaging Endoscopy for Colorectal Polyps.

BACKGROUND & AIMS: This study examined the additional value of magnifying chromoendoscopy (MCE) on magnifying narrow-band imaging endoscopy (M-NBI) in the optical diagnosis of colorectal polyps. METHODS: A multicenter prospective study was conducted at 9 facilities in Japan and Germany. Patients with colorectal polyps scheduled for resection were included. Optical diagnosis was performed by M-NBI first, followed by MCE. Both diagnoses were made in real time. MCE was performed on all type 2B lesions classified according to the Japan NBI Expert Team classification and other lesions at the discretion of endoscopists. The diagnostic accuracy and confidence of M-NBI and MCE for colorectal cancer (CRC) with deep invasion (≥T1b) were compared on the basis of histologic findings after resection. RESULTS: In total, 1173 lesions were included between February 2018 and December 2020, with 654 (5 hyperplastic polyp/sessile serrated lesion, 162 low-grade dysplasia, 403 high-grade dysplasia, 97 T1 CRCs, and 32 ≥T2 CRCs) examined using MCE after M-NBI. In the diagnostic accuracy for predicting CRC with deep invasion, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for M-NBI were 63.1%, 94.2%, 61.6%, 94.5%, and 90.2%, respectively, and for MCE they were 77.4%, 93.2%, 62.5%, 96.5%, and 91.1%, respectively. The sensitivity was significantly higher in MCE (P < .001). However, these additional values were limited to lesions with low confidence in M-NBI or the ones diagnosed as ≥T1b CRC by M-NBI. CONCLUSIONS: In this multicenter prospective study, we demonstrated the additional value of MCE on M-NBI. We suggest that additional MCE be recommended for lesions with low confidence or the ones diagnosed as ≥T1b CRC. Trials registry number: UMIN000031129.

Modified double-layered suturing for a mucosal defect after colorectal endoscopic submucosal dissection (Origami method) (with video).

BACKGROUND AND AIMS: Through-the-scope clips (TTSCs) are among the most common devices used to close colorectal post-endoscopic submucosal dissection (ESD) defects. Although TTSCs are easy to deliver, even to the proximal colon, simple clipping of large defects results in mucosa-mucosa closure, which could be unreliable. We developed a novel endoscopic closure technique using a modified double-layered suturing called the origami method (OGM). This method closes not only the mucosal layer but also the muscle layer with only TTSCs, which can obtain robust closure even for large defects. This study aimed to evaluate the feasibility of this new closure method for colorectal post-ESD defects. METHODS: This retrospective observational study was conducted at a tertiary care hospital. We reviewed the cases of the OGM attempted after colorectal ESD at our institute between October 2021 and October 2022 and measured the clinical characteristics and outcomes of enrolled cases. RESULTS: The OGM was attempted in 47 cases after colorectal ESD. Thirty-one cases (66%) were in the proximal colon, 5 (11%) in the distal colon, 6 (13%) in the upper rectum, and 5 (10%) in the lower rectum. The median defect size was 38 mm, with the largest being 85 mm. Complete closure was achieved in 44 cases (94%), including all lower rectum cases. No perforations were caused by clips during closure, and delayed perforation and bleeding were not observed. CONCLUSIONS: This new closure method is feasible and recommended. The OGM could achieve reliable closure of large defects in any location, including the proximal colon and thick-walled lower rectum, using only TTSCs.

Closure of large mucosal defects for prevention of strictures after duodenal endoscopic submucosal dissection (with video).

BACKGROUND AND AIMS: Although lesions occupying a large circumference are associated with the risk of post-endoscopic submucosal dissection (ESD) strictures, the corresponding data for duodenal lesions are unknown. We aimed to analyze the incidence of post-ESD strictures after wide-field duodenal ESD. METHODS: In this retrospective study of duodenal lesions treated with ESD between July 2010 and August 2021, we included lesions that resulted in mucosal defects occupying more than half of the circumference and excluded lesions located in bulbs and involving Vater's papilla. We analyzed the incidence rates of stricture and luminal narrowing, in addition to bleeding and perforation as the outcomes in this study. Stricture was defined as the inability of the endoscope to pass through the lumen. A single endoscopist reviewed all endoscopic images and judged the degree of luminal narrowing. RESULTS: Eighty lesions were included, of which 2 involved mucosal defects occupying more than 90% of the circumference. The wound was closed, at least partially, in 90% in all lesions and in 86% of lesions with a mucosal defect occupying more than 75% of the circumference. None of the lesions caused delayed perforation and stricture, whereas 2 lesions caused delayed bleeding. Only 6 lesions caused luminal narrowing. When examined by the degree of closure, the rate of luminal narrowing increased with complete closure, incomplete closure, and nonclosure (4.9%, 9.1%, and 25.0%, respectively). CONCLUSIONS: Suturing may prevent post-ESD bleeding and perforation as well as stricture formation in cases of duodenal tumors, with mucosal defects occupying a large circumference.

Intensive endoscopic resection strategy for multiple duodenal polyposis associated with familial adenomatous polyposis.

BACKGROUND AND AIM: Multiple duodenal polyposis associated with familial adenomatous polyposis (FAP) is a high risk of duodenal cancer development. We evaluated the feasibility of intensive endoscopic resection that is a comprehensive treatment strategy combining multiple kinds of endoscopic treatments. METHODS: This is a retrospective observational study. From January 2012 to July 2022, a total of 28 consecutive patients in FAP who underwent endoscopic resection for multiple duodenal polyposis more than twice were included. Various endoscopic treatments, such as cold polypectomy (CP), endoscopic mucosal resection (EMR), underwater EMR (UEMR), endoscopic submucosal dissection (ESD), and endoscopic papillectomy (EP), were applied depending on lesions size and location. We evaluated individual information from patients' medical records, including patient characteristics, lesion characteristics, details of endoscopic treatment, pathologic findings, and Spigelman index (SI). We compared the differences in the number of treatments and observation periods with and without SI decrease. RESULTS: A total of 1040 lesions were removed by 138 sessions of endoscopic resections. The median follow-up period was 3.2 years. At the beginning of the endoscopic intervention, median SI was 9 (6-11) and the proportion of Spigelman stage (SS) IV was 61%. Repeated endoscopic treatments finally reduced SI in 26 patients (93%), and the proportion of SS IV significantly decreased to 13% with every endoscopic treatment. The mean SI change was -4.2 points per year (95% confidence interval: -0.6 to -5.9). There were no patients required surgical duodenectomy during the follow-up period. CONCLUSION: Intensive resection has a potential of downstaging duodenal lesions associated with FAP.

Potential of temperature-response collagen-genipin sol as a novel submucosal injection agent for endoscopic resection: Acute and chronic phase study using living animals.

OBJECTIVES: We proposed a novel temperature-response collagen sol as a submucosal injection agent for endoscopic resection (ER) using pepsin-solubilized collagen (PSC) and genipin (Ge) in a prior study. This study aimed to evaluate the usefulness and safety of the sol (PSC/Ge) in acute and chronic phase experiments using living animals. METHODS: In experiment 1, we performed endoscopic submucosal dissection (ESD) for six pigs using normal saline (NS), sodium hyaluronate (SH), and PSC/Ge. We compared the required amount of each agent per unit area and procedure time. In experiment 2, we created artificial ulcers with endoscopic mucosal resection (EMR) for five pigs using NS and PSC sol. We compared the artificial ulcer residual rate at 7 and 14 days after EMR, and the scarring rate at 14 days after EMR. RESULTS: The required amount of agents per unit area for PSC/Ge (0.8 ± 0.8 mL/cm2 ) and SH (1.1 ± 0.8 mL/cm2 ) were significantly smaller than that for NS (1.8 ± 0.7 mL/cm2 ). The total procedure time did not have a statistical difference. The artificial ulcer residual rates were 47.3 ± 0.7% for NS and 40.3 ± 0.7% for PSC/Ge on day 7 (P = 0.51), and 15.0 ± 0.1% for NS and 10.2 ± 0.1% for PSC/Ge sol on day 14 (P = 0.35). The scarring rate on day 14 was 10% for NS and 20% for PSC/Ge. CONCLUSION: We demonstrated the feasibility of a novel temperature-response collagen gel as a submucosal injection agent for ER in the acute and chronic phase animal experiment.

Novel closure method for a large mucosal defect after endoscopic resection: String clip suturing method with an anchor.

Duodenal endoscopic submucosal dissection (ESD) is a high-risk technique; however, prophylactic closure of mucosal defects reduces the risk. Unfortunately, we have encountered cases where closure is difficult, especially in large lesions. Therefore, we developed a novel closure technique, a string clip suturing method with an anchor (SCSM-A). This study aimed to elucidate the feasibility of this method. Five patients underwent this method for the closure of mucosal defects after duodenal ESD. The initial string clip was deployed at the anal end of the mucosal defects and the second clip was deployed at the other end of the mucosal defect. A third clip was deployed on the muscular layer in the middle of the mucosal defect. The free end of the string was pulled, and additional clips were deployed around the first to the third clips for complete closure. Because of grasping the muscle layer, SCSM-A can be employed for secure closure without creating a pocket. We reviewed the background and clinical course of hospitalization of patients who underwent this method. The resected specimens ranged from 52 to 103 mm in diameter. Complete closure of the mucosal defects was possible in all the cases. There were no adverse events, and no cases required additional treatment. All the patients were discharged within 7 days. The new method achieved secure closure even for large mucosal defects after duodenal ESD. This is a technique that can be applied to other organs, e.g., the colon.

Prospective cross-organ analysis for the causes of fever and increased inflammatory response after endoscopic resection.

OBJECTIVES: Fever and increased inflammatory responses sometimes occur following endoscopic resection (ER). However, the differences in causes according to the organ are scarcely understood, and several modified ER techniques have been proposed. Therefore, we conducted a comprehensive prospective study to investigate the cause of fever and increased inflammatory response across multiple organs after ER. METHODS: We included patients who underwent gastrointestinal endoscopic submucosal dissection (ESD) and duodenal endoscopic mucosal resection at our hospital between January 2020 and April 2022. Primary endpoints were fever and increased C-reactive protein (CRP) levels following ER. The secondary endpoints were risk factors for aspiration pneumonia. Blood tests and radiography were performed on the day after ER, and computed tomography was performed if the cause was unknown. RESULTS: Among the 822 patients included, aspiration pneumonia was the most common cause of fever and increased CRP levels after ER of the upper gastrointestinal tract (esophagus, 53%; stomach, 48%; and duodenum, 71%). Post-ER coagulation syndrome was most common after colorectal ESD (38%). On multivariate logistic regression analysis, lesions located in the esophagus (odds ratio [OR] 3.57; P < 0.001) and an amount of irrigation liquid of ≥1 L (OR 3.71; P = 0.003) were independent risk factors for aspiration pneumonia. CONCLUSIONS: Aspiration pneumonia was the most common cause of fever after upper gastrointestinal ER and post-ER coagulation syndrome following colorectal ESD. Lesions in the esophagus and an amount of irrigation liquid of ≥1 L were independent risk factors for aspiration pneumonia.

Feasibility Study of Partial Submucosal Injection Technique Combining Underwater EMR for Superficial Duodenal Epithelial Tumors.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) and Underwater EMR have been reported as effective endoscopic treatment for superficial duodenal tumor (SDET). However, a notable problem of EMR for SDET is technical difficulty for the lesion with non-lifting sign, and it of UEMR is that en bloc resection rate is relatively low. Therefore, we performed partial submucosal injection combining UEMR (PI-UEMR). The aim of this study is to evaluate feasibility and safety of this technique for duodenal tumor. METHODS: This is a prospective observational study from tertiary care hospital. We performed PI-UEMR in patients with SDET that is 13-20 mm in diameter, or less than 13 mm with technical difficulty for EMR and UEMR from January 2019 to March 2020. Primary outcome was en bloc resection rate. Secondary outcomes were R0 resection rate, mean total procedure time, intra- and post-procedure complication. RESULTS: Thirty patients were included in this study. Mean age was 62 ± 12 years old. Three fourths lesions were located at anal side from major papilla. Median lesion size was 12 mm [IQR 10-16 mm]. Twenty-four cases were taken endoscopic biopsy in prior hospital and observed biopsy scar. En bloc resection rate was 97%. Ro resection rate was 83%. Mean total procedure time was 17 ± 12 min. And there was an only one case of complication, intra-procedure bleeding that was controllable endoscopically. CONCLUSIONS: PI-UEMR might be very useful and safe technique of endoscopic resection for SDET including relatively large lesions.

Feasibility of endoscopic resection for large pedunculated duodenal lesions (with video).

BACKGROUND: A standard treatment method for pedunculated duodenal lesions has not yet been established. This study aimed to evaluate the feasibility of endoscopic resection (ER) for pedunculated duodenal lesions, especially for large lesions. METHODS: This study retrospectively reviewed cases of pedunculated duodenal lesions treated with ER at our institute between July 2010 and January 2021. We collected data on the clinical characteristics and treatment outcomes. In addition, the cases were divided based on the treatment provided for the lesion, i.e., the ESD and snare resection groups, and we compared the data between the two groups. RESULTS: Thirty-eight cases were included in this study. The overall en bloc resection rate was 95%. No perforation occurred in any of the cases. There were 10 cases treated with ESD, which were considered difficult to achieve en bloc resection using snare forceps, and 28 cases treated with snare resection. Although the median lesion size was significantly larger in the ESD group than in the snare resection group (27 [range 23-66] vs. 19 [range 6-55] mm, P = 0.0052), treatment outcomes were not significantly different between the two groups. Among the 10 cases treated using ESD, en bloc resection was achieved in all cases, along with specimen retrieval without any perforations, despite the large size of the lesions. CONCLUSION: ER could be performed to achieve a high en bloc resection rate without any perforations in pedunculated duodenal lesions, even in extremely large (e.g., ≧ 60 mm) lesions, suggesting that ER is feasible and may be an alternative to surgical resection for large pedunculated duodenal lesions.

Red dichromatic imaging reduces bleeding and hematoma during submucosal injection in esophageal endoscopic submucosal dissection.

BACKGROUND: Bleeding and hematoma formation during submucosal injection in esophageal endoscopic submucosal dissection (ESD) reduce the visibility of the submucosa. Red dichromatic imaging (RDI) is an endoscopic technique that provides better visualization of the deep submucosal blood vessels. We speculated that blood vessel injury could be avoided with RDI. This pilot study evaluated the role of RDI in preventing bleeding and hematoma formation during esophageal ESD. METHODS: This was a single-center retrospective observational study. We examined 60 patients who underwent ESD with white light imaging (WLI) and RDI. A single endoscopist reviewed all of the surgical videos to document the incidence and severity of bleeding episodes. Eighteen videos provided adequate quality and detail, and the number of blood vessels traversing the mucosal incision lines of the lesions in these videos was evaluated under WLI and RDI. RESULTS: The WLI group had a significantly higher incidence of hematomas per unit area compared to the RDI group (0.18/cm2 [range 0-0.38] vs. 0 [0-0.18]/cm2, p = 0.024). The WLI group also had a significantly higher incidence of total bleeding episodes compared to the RDI group (42.9% [range 21.7-60.4] vs 16.7% [range 13.8-22.9], p < 0.001). Significantly more blood vessels were visible under RDI compared to WLI (5 [range 4-8] vs. 2 [range 1-5], p = 0.0020). CONCLUSION: RDI reduced the incidence of bleeding and hematoma formation during submucosal injection in esophageal ESD. It was assumed that the improvement of blood vessel visibility by RDI might have contributed to the result.

Closure of gastric perforations during endoluminal resection using a novel biodegradable collagen sol: A feasibility survival study on porcine model (with video).

OBJECTIVE: A prior study using porcine colon demonstrated the feasibility of a novel injectable, temperature?responsive, and biodegradable collagen sol (ICS) that transforms from a liquid to a gel state in response to body temperature for endoscopic closure of perforation during endoscopic resection (ER). This study aims to report the acute and survival outcomes of ICS for gastric perforations during ER. METHODS: In two experiments using nine live pigs under general anesthesia, four and six perforations (3-5\xA0mm) were created using an electrosurgical knife in acute and survival experiments, respectively. ICS was delivered to the perforations using an endoscopic catheter. In Experiment 1, a leak test and histopathology were performed on all explanted stomachs after euthanization. In Experiment 2, perforation sites were assessed by gastroscopy and histopathology 7, 14 and 28\xA0days post? RESULTS: In Experiment 1, gastroscopy confirmed complete closure of the perforations with ICS and no evidence of leak. Subsequent histopathology revealed a fixation of collagen gel (CG) as a sealant agent at the perforation sites. There were no adverse effects related with ESD or the use of ICS. In Experiment 2, histopathology revealed a fixation of CG as a sealant agent, replacement with granulation tissue and no CG; and fibrotic tissue at 7, 14 and 28\xA0days, respectively. CONCLUSIONS: This study presents a novel method using ICS, demonstrating promising efficacy and safety profile for endoscopic closure of perforations during ER. Further studies are necessary before translating to clinical use.

Efficacy of partial injection underwater endoscopic mucosal resection for superficial duodenal epithelial tumor: Propensity score-matched study (with video).

BACKGROUND AND AIM: Underwater endoscopic mucosal resection (UEMR) has been reported as effective endoscopic treatment for superficial duodenal epithelial tumors (SDETs). However, it has been reported that a notable problem of UEMR for SDETs is that en bloc resection rate is relatively low. Therefore, we proposed a novel technique to improve en bloc resection rate: UEMR combining partial submucosal injection (PI-UEMR). The aim of this study is to evaluate efficacy and safety of PI-UEMR for SDETs by comparing to UEMR. METHODS: This is a retrospective observational study in a single center. The patients who underwent UEMR or PI-UEMR from June 2010 to August 2020 were included in this study. Eligible patients were selected from included patients in a 1:1 ratio using propensity score matching. The clinical outcomes of endoscopic resection (procedure time, en bloc resection rate, complication rate [immediate perforation, delayed bleeding, delayed perforation]), and histopathological diagnosis (adenoma/cancer) were compared between each group. RESULTS: Two hundred and twenty-eight patients were included in this study. Of included patients, 47 patients were selected in each group by propensity score matching. There were no statistical differences in procedure time (11 ± 1.2 min vs. 9 ± 1.2 min, P = 0.30), complication rate (immediate perforation [0% vs. 2%, P = 0.12], delayed bleeding [0% vs. 2%, P = 0.12], and no delayed perforation) and histopathological diagnosis (adenoma; 100% vs. 96%, P = 0.14) in each group. However, en bloc resection rate of PI-UEMR was significantly higher than UEMR (96% vs. 83%, P < 0.05). CONCLUSION: Partial submucosal injection UEMR might be superior procedure for en bloc resection in SDETs compare to UEMR.

Endoscopic hand suturing for mucosal defect closure after gastric endoscopic submucosal dissection may reduce the risk of postoperative bleeding in patients receiving antithrombotic therapy.

OBJECTIVES: Endoscopic hand suturing (EHS) is expected to decrease the risk of post-endoscopic submucosal dissection (ESD) bleeding by closing mucosal defects. We investigated the efficacy of EHS after gastric ESD in patients with antithrombotic agents. METHODS: In this prospective single-arm trial, patients taking antithrombotic agents for cardiovascular disease, arrhythmia, cerebrovascular disease and/or peripheral arterial disease and having <3-cm gastric neoplasms were recruited. The mucosal defects after ESD were closed by EHS in which the needle was delivered through an overtube, and the mucosal rim of the defect was continuously sutured in a linear fashion by manipulating the needle grasped with the needle holder, followed by cutting the remnant suture and retrieval of the needle. The primary endpoint was the incidence of postoperative bleeding within 4 weeks after ESD. RESULTS: Twenty-two lesions in 20 patients (continuing antiplatelet agents in 11, anticoagulant agents in eight, both in one) underwent ESD followed by EHS. All defects (median size, 30 mm; range, 12-51 mm) were completely closed by EHS and remained closed on postoperative day 3. The median number of stitches was six (range, 4-8) and median suturing time was 36 (range, 24-60) min. There were no adverse events during/after EHS or postoperative bleeding. CONCLUSIONS: Postoperative bleeding was not observed in patients taking antithrombotic agents without perioperative cessation. EHS appears to be useful for prevention of post-gastric ESD bleeding in high-risk patients. (Clinical registration number: UMIN000024184).

Predictors of technical difficulty for complete closure of mucosal defects after duodenal endoscopic resection.

BACKGROUND AND AIMS: It has been reported that the prophylactic closure of mucosal defects after duodenal endoscopic resection (ER) can reduce delayed adverse events; however, under certain circumstances, this can be technically challenging. Therefore, the aim of this study was to determine the predictors of difficulty during the complete closure of mucosal defects after duodenal ER. METHODS: This was a retrospective study of duodenal lesions that underwent ER between July 2010 and May 2020. We reviewed the endoscopic images and analyzed the relationships between the degree of closure or closure time and clinical features of the lesions using univariate and multivariate analyses. RESULTS: We analyzed 698 lesions. The multivariate analysis revealed that lesion location in the medial or anterior wall (odds ratio, 2.8; 95% confidence interval, 1.36-5.85; P < .01) and a large lesion size (odds ratio, 1.4; 95% confidence interval, 1.07-1.89; P = .03) were independent predictors of an increased risk of incomplete closure. Moreover, a large lesion size (ß coefficient, .304; P < .01), an occupied circumference over 50% (ß coefficient, .178; P < .01), intraoperative perforation (ß coefficient, .175; P < .01), treatment period (ß coefficient, .143; P < .01), and treatment with endoscopic submucosal dissection (ß coefficient, .125; P < .01) were independently and positively correlated with a prolonged closure time in the multiple regression analysis. CONCLUSIONS: This study revealed that lesion location in the medial or anterior wall and lesion size affected the incomplete closure of mucosal defects after duodenal ER, and lesion size, occupied circumference, intraoperative perforation, treatment period, and treatment method affected closure time.

Water pressure method for duodenal endoscopic submucosal dissection (with video).

BACKGROUND AND AIMS: Duodenal endoscopic submucosal dissection (ESD) is considered technically challenging and has a high risk of adverse events. However, we recently made some progress with the ESD technique and device by introducing 2 features: a water pressure (WP) method and a second-generation ESD knife (DualKnife) with a water jet function (DualKnife J). The present study aimed to assess whether these changes improved the clinical outcomes of duodenal ESD. METHODS: This was a retrospective observational study. Among all patients who underwent ESD for superficial duodenal epithelial tumors from June 2010 to December 2018, patients in whom a single expert performed the procedure were included in this study. Various factors, including the use of the WP method and ESD devices (DualKnife or DualKnife J) and the treatment phase (early, mid, and late), were analyzed to determine whether they were associated with intraprocedural perforation and procedure time. Treatment phase was assigned by dividing the study population equally into 3 subgroups according to the treatment phase. RESULTS: The procedure time was significantly shorter, and the proportion of patients with intraprocedural perforations was the lowest in the late phase. Multivariate analysis of the use of the WP method revealed that it significantly decreased the intraprocedural perforation rate (odds ratio, 0.39; 95% confidence interval, 0.16-0.96), and analysis of the use of both the WP method (ß coefficient, -0.40; P < .01) and the DualKnife J (ß coefficient, -0.10; P = .032) revealed they were independently and negatively correlated with procedure time. CONCLUSION: The present study reveals that the WP method significantly reduced the intraprocedural perforation rate and that both the WP method and the DualKnife J significantly shortened procedure times for duodenal ESD.

A Case of Duodenal Tumor Adjacent to the Diverticulum That Was Resected by the Technique of Partial Submucosal Injection Combined with Underwater Endoscopic Mucosal Resection.

A 66-year-old male was referred to our hospital for treatment of duodenal tumor. The most difficult part was that the lesion was adjacent to duodenal diverticulum. Endoscopic mucosal resection (EMR) was difficult because submucosal injection spread broadly and quickly and makes it difficult to visualize the diverticulum edge of the lesion. Simple underwater EMR (UEMR) had risk for perforation at the diverticulum part because duodenal diverticulum is spurious diverticulum that defects the proper muscle layer. Therefore, to make sufficient distance between diverticulum and the lesion, we performed partial submucosal injection into only the diverticulum side of the lesion combined with simple UEMR. The lesion was resected en bloc without any adverse events. Histopathological diagnosis was tubular adenoma with moderate atypia and surgical margin negative. Partial submucosal injection combined with simple UEMR might be useful for duodenal tumor that has any technical difficulties as in this case.

Novel temperature-responsive, biodegradable and injectable collagen sol for the endoscopic closure of colonic perforation holes: Animal study (with videos).

OBJECTIVES: Endoscopic submucosal dissection (ESD) poses a risk of intraprocedural perforation. We have developed a biodegradable injectable collagen sol that undergoes a liquid-to-gel formation in response to body temperature. Here, we investigated the feasibility of this novel collagen sol for the endoscopic closure of iatrogenic perforation holes. METHODS: In two experiments, 12 and 5 colonic perforation holes (3-5 mm) were made using an ESD knife in four and three live pigs under general anesthesia, respectively. In Experiment 1, collagen sol was delivered to the perforation holes using an endoscopic catheter. When the colon was expanded by CO2 insufflation, endo-clips were applied to the perforation holes. For Experiment 2, Collagen sol adjusted based on the Experiment 1 results was delivered to the perforation holes in the same manner. A leak test was performed for every colon after the pigs were killed, and the histology of the perforation sites was evaluated. RESULTS: In both experiments, collagen sol was smoothly delivered to the target area and fixed as a gel on the perforation holes. Experiment 1, 83% (10/12) of the perforation holes were completely closed, and all endo-clips were placed with composure. Experiment 2, all perforation holes were completely closed with collagen gel. There was no leak from the perforation holes. Histology revealed a fixation of the collagen gel as an embolus agent in the perforation holes. CONCLUSIONS: This novel collagen sol may be used for the endoscopic closure of intraprocedural perforation. Further studies will determine this collagen sol's clinical feasibility and safety.