Efficacy and safety of the water pressure method for endoscopic submucosal dissection in superficial pharyngeal cancer.

Background and study aims Superficial pharyngeal cancers can be cured with transoral surgery (TOS), which preserves organ function and quality of life. Pharyngeal endoscopic submucosal dissection (ESD) is challenging to perform because of limited maneuverability and complex anatomical features. The water pressure method (WPM) is useful for natural traction techniques during ESD and is potentially useful for pharyngeal ESD. This study aimed to investigate the short-term outcomes of WPM-ESD for pharyngeal lesions. Patients and methods Therapeutic outcomes of patients who underwent WPM-ESD for pharyngeal lesions at Keio University between May 2019 and February 2022 were retrospectively analyzed. Results Twenty-one pharyngeal lesions treated with WPM-ESD were analyzed. Three lesions were located in the oropharynx and 18 in the hypopharynx. All ESD procedures were performed under general anesthesia. The endoscopic en bloc resection rate was 100%. The median procedure time was 15 minutes (range 4-45 minutes). All patients were successfully extubated on the day of ESD. No serious adverse events (AEs) related to WPM-ESDs were observed. None of the patients required nasogastric intubation, percutaneous endoscopic gastrostomy, or tracheotomy. The median fasting time and hospital stay were 2 days (range 2-5 days) and 6 days (range 6-10 days), respectively. All the histological results indicated squamous cell carcinoma. The complete histologic resection rate was 76.2%. Conclusions WPM-ESD achieved a high en bloc resection rate and short procedure time without serious AEs. Thus, it may be a useful treatment for pharyngeal lesions.

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.

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.

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.

Effectiveness of water pressure method in colorectal endoscopic submucosal dissection by novice endoscopists.

Background and study aims Colorectal endoscopic submucosal dissection (ESD) remains challenging for novice endoscopists. Not only the underwater conditions but also active use of water pressure with the water pressure method (WPM) can help widen the submucosal layer. This study aimed to clarify the usefulness of WPM in colorectal ESD, especially for novice endoscopists. Methods This study was ex vivo and enrolled three novices. Each endoscopist performed conventional ESD (C-ESD) and ESD with WPM (WPM-ESD) 10 times on an excised bovine rectum. The treatment outcomes were compared between the two groups. Results Median procedure time was significantly shorter in the WPM-ESD group than in the C-ESD group (54 minutes, interquartile range [IQR] 42-67 vs. 45 minutes, IQR 34-55, P = 0.035). Although no significant difference in the activation time of electrical surgical unit (ESU) during the procedure was noted, the interval time during the procedure at which the ESU was not activated was significantly shorter in the WPM-ESD group (52 minutes, IQR 40-65 vs. 42 minutes, IQR 32-52, P = 0.030) than in the C-ESD group. Moreover, the time required for the endoscope to enter the submucosa was significantly shorter in the WPM-ESD group than in the C-ESD group (8.0 minutes, IQR 6.0-10 vs. 5.0 minutes, IQR 3.0-6.0, P < 0.001). Conclusions The present study reveals that the WPM method significantly shortens the procedure times for novices in colorectal ESD, especially the interval time, which refers to the time spent creating the field of view, and the time required for the endoscope to enter the submucosa.

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.

First clinical experience with esophageal ESD using a novel adjustable traction device.

Background and study aims In esophageal endoscopic submucosal dissection (ESD), the effectiveness of traction including clip-thread method has been reported, but it is difficult to adjust the direction of traction. Therefore, we developed a dedicated over-tube type traction device (ENDOTORNADO) that has a working channel and allows traction from any directions by rotating itself. We investigated the clinical feasibility and potential usefulness of this new device in esophageal ESD. Patients and methods This was a single-center, retrospective study. Six cases of esophageal ESD with ENDOTORNADO from January to March 2022 (tESD group) were compared with 23 cases of conventional esophageal ESD performed by the same operator from January 2019 to December 2021 (cESD group) in terms of clinical treatment outcomes. Results In all cases, en bloc resection was achieved without intraoperative perforation. The total procedure speed was significantly increased in tESD group (23 vs. 30 mm 2 /min, P  = 0.046). In particular, the submucosal dissection time was significantly reduced to about one-quarter in tESD group (11 vs. 42 min, P  = 0.004). Conclusions ENDOTORNADO creates the adjustable traction from any directions and may have the clinical feasibility. It would be an option for human esophageal ESD.

Colorectal endoscopic submucosal dissection using the water pressure method for diverticulum-associated lesions: A case series study (with video).

Background and study aims Colorectal endoscopic submucosal dissection (ESD) of diverticulum-associated lesions is challenging because these lesions require precise excision in narrow spaces. The water pressure method (WPM) uses active water pressure by the waterjet function under saline solution-filled conditions. This study aimed to determine the feasibility of WPM for resection of diverticulum-associated lesions. Patients and methods This was a retrospective, observational case series study. We reviewed diverticulum-associated lesions treated by ESD with WPM at our institution between June 2017 and July 2021. Diverticulum-associated lesions were classified as follows: type 1, lesions in contact with or within 3 mm of the edge of a diverticulum; type 2, lesions that partially infiltrated the interior of a diverticulum; and type 3, lesions that infiltrated the interior of and completely covered the diverticulum. We collected data on the clinical characteristics and outcomes of the lesions. Results Seven diverticulum-associated lesions were treated with ESD using WPM. The median lesion size was 37 mm (interquartile range: 25-54 mm). There were three cases of type 1, three cases of type 2, and one case of type 3. Three lesions were resected circumventing the diverticulum, and four lesions involved resection of the diverticulum. The en bloc resection and R0 resection rates were 86 %. One patient had severe fibrosis, which caused perforation, and in another patient, the diverticulum was too deep and narrow to be completely isolated. Conclusions WPM allowed for precise procedures in the diverticulum. The feasibility of WPM has been suggested for diverticulum-associated lesions, although cases have been complex.

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.

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.

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.

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.

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.

Differential diagnosis of superficial duodenal epithelial tumor and non-neoplastic lesion in duodenum by magnified endoscopic examination with image-enhanced endoscopy.

BACKGROUND: Differential diagnosis of superficial duodenal epithelial tumors (SDETs) and non-neoplastic lesions (NNLs) in duodenum by endoscopy is difficult. Here, we attempted to distinguish them by magnified endoscopic examination with image-enhanced endoscopy (IEE-ME). METHODS: Various IEE-ME findings of 95 SDETs who underwent endoscopic resection and 58 NNLs who underwent biopsy were retrospectively reviewed. RESULTS: When we compared the IEE-ME findings of SDETs and NNLs, the presence of demarcation line (DL) (97.9% vs. 79.3%, P = 0.0002), white opaque substance (WOS) (84.2% vs. 1.7%, P < 0.0001) and light blue crest (LBC) (93.7% vs. 32.8%, P < 0.0001) and the absence of enlarged marginal epithelium (EME) (98.9% vs. 62.1%, P < 0.0001) were significantly more frequent in SDETs than NNLs. When divided into each superficial structure, it was the most effective to evaluate the combination of WOS and LBC as SDET with open-loop structure (OLS), and the combination of DL and EME as SDET with closed-loop structure (CLS). However, LBC was excluded because of low inter- and intra-observer agreements. Finally, the sensitivity, specificity and accuracy for the diagnosis of SDETs were 88.4%, 98.3% and 92.2%, respectively, and we developed an algorithm for the differential diagnosis of duodenal lesions. CONCLUSION: We could distinguish SDET from NNL, diagnosed SDET as presence of WOS indicated OLS of superficial structure, and presence of DL and absence of EME indicated CLS of superficial structure.

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).

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.

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.

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.