Background Duodenal endoscopic submucosal dissection (ESD) remains technically challenging, with a high risk of severe adverse events. Because exposure of the duodenal post-ESD mucosal defect to pancreatic juice and bile acid reportedly induces delayed perforation and bleeding, we examined whether defect closure using an over-the-scope clip (OTSC) system was useful for preventing postoperative adverse events. Methods From April 2016 to February 2017, a total of 50 consecutive patients with superficial non-ampullary duodenal epithelial tumors (SNADETs) larger than 10 mm, with no more than semi-circumferential spread, were prospectively enrolled in this study. All of the lesions were treated by experienced ESD operators and the post-ESD mucosal defect was closed using OTSCs. Results All of the SNADETs were completely removed by ESD, with an R0 resection rate of 88.0 %. The mean procedure and closure times were 67.3 ± 58.8 minutes and 9.8 ± 7.2 minutes, respectively. Although complete defect closure was achieved in 94.0 % of the patients (47/50), two patients required surgical conversion. Delayed perforation occurred in only one patient (2.1 %), who did not have successful closure of the defect, as misplacement of the OTSC exposed the muscle layer. Meanwhile, delayed bleeding occurred in three patients (6.3 %); however, the bleeding was easily controlled using endoscopic coagulation. The mean duration of postoperative hospitalization was 5.5 ± 7.2 days. Conclusions Prophylactic defect closure using OTSCs may be effective in reducing severe adverse events after duodenal ESD.

Background and study aim: There is no enough data for endoscopic resection (ER) of superficial duodenal epithelial tumors (SDETs) due to its rarity. There are two main kinds of ER techniques for SDETs: EMR and ESD. In addition, modified EMR techniques, underwater EMR (UEMR) and cold polypectomy (CP), are getting popular. We conducted a large-scale retrospective multicenter study to clarify detailed outcomes of duodenal ER. Patients and methods : Patients with SDETs who underwent ER at 18 institutions from January 2008 to December 2018 were included. The rates of en bloc resection and delayed adverse events (AEs) (defined as delayed bleeding or perforation) were analyzed. Local recurrence was analyzed using Kaplan-Meier method. Results: In total, 3107 patients (including 1017 receiving ESD) were included. En bloc resection rates were 79.1%, 78.6%, 86.8%, and 94.8%, and delayed AE rates were 0.5%, 2.2%, 2.8%, and 7.3% for CP, UEMR, EMR and ESD, respectively. The delayed AE rate was significantly higher for ESD group than non-ESD group among lesions less than 19 mm (7.4% vs 1.9%, p<0.0001), but not among lesions larger than 20 mm (6.1% vs 7.1%, p=0.6432). The local recurrence rate was significantly lower in ESD group than non-ESD group (p<0.001). Furthermore, for lesions larger than 30 mm, the cumulative local recurrence rate at 2 years was 22.6% in non-ESD group compared to only 1.6% in ESD group (p<0.0001). Conclusions: ER outcomes for SDETs were generally acceptable. ESD by highly experienced endoscopists might be an option for very large SDETs.

Aim To analyze factors involved in procedural failure and to discuss responses to procedural failure by using the outcomes of endoscopic retrograde cholangiopancreatography (ERCP) carried out using a short‐type single‐balloon enteroscope (short SBE) in patients with surgically altered gastrointestinal anatomy. Methods The study sample included patients who underwent ERCP‐related procedures using a short SBE between September 2011 and September 2018 at our hospital. Outcomes, including procedural success rate, were studied retrospectively to analyze the factors involved in procedural failure. Results Analysis included 191 procedures carried out in 121 patients. Procedural success rate was 85.9% with an adverse event rate of 8.4%. Causes of procedural failure included malignant biliary obstruction (odds ratio [OR] 2.89, 95% confidence interval [CI] 1.19–7.25, P = 0.02), first ERCP attempt (OR: 5.32, 95% CI: 1.30–36.30, P = 0.02), and Roux‐en‐Y reconstruction (OR: 0.08, 95% CI: 0.004–0.39, P < 0.001). With regard to the response to failure, in cases of malignant biliary obstruction, reattempted short SBE‐assisted ERCP was difficult because of invasion of the small intestine or papilla. A large number of these cases required alternative treatment (10 of 15 cases, 66.7%) using percutaneous transhepatic biliary drainage (PTBD) or endoscopic ultrasound‐guided biliary drainage (EUS‐BD). Conclusion Endoscopic retrograde cholangiopancreatography using a short SBE is safe and effective, with malignant biliary obstruction being a specific cause of failure. Technical proficiency with different modalities, such as PTBD and EUS‐BD, is necessary to respond to failure in these cases.

Background and Aims: Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy is still challenging. Usefulness of single-balloon enteroscopy (SBE)-assisted ERCP has been increasingly reported. Short SBE is considered beneficial with a 152-cm working length and a 3.2-mm working channel. This has increased the variety of devices that can be used during ERCP procedures. The aim of this pooled analysis was to evaluate the efficacy of SBE-assisted ERCP in patients with surgically altered anatomy and elucidate the current status.Methods: This systematic review only involved biliary interventions which excluded pancreatic cases. Studies involving SBE-assisted ERCP in patients with Roux-en-Y gastrectomy, hepaticojejunostomy with Roux-en-Y, pancreaticoduodenectomy (Whipple or Child procedure), or Billroth II gastrectomy were analyzed. Enteroscopy, biliary cannulation, and procedural success were assessed by pooling data in a random-effect model, according to the degree of heterogeneity, to obtain a proportion with 95% confidence interval (CI). The outcomes observed for conventional and short SBE cases were also reported.Results: Overall, 1227 SBE-assisted ERCP procedures from 21 studies were included. The pooled enteroscopy, biliary cannulation, and procedural success rates were 86.6% (95% CI, 82.4-90.3%), 90% (95% CI, 87.1-92.5%), and 75.8% (95% CI, 71.0-80.3%), respectively. Adverse events occurred in 6.6% (95% CI, 5.3-8.2%) of the procedures. Although good outcomes were reported for short SBE-assisted ERCP, these should not be directly compared to the outcomes observed for conventional SBE, as they assume different backgrounds and include confounding variables.Conclusions: Single-balloon enteroscopy-assisted ERCP in patients with surgically altered anatomy on biliary interventions is effective.

Background and study aims: Despite the clinical advantages of colorectal endoscopic submucosal dissection (ESD), an effective training system, especially for Western endoscopists, has been challenging to establish. Herein, we propose a novel training program using ex vivo animal models and evaluate the learning curve of colorectal ESD trainees without gastric ESD experience. Patients and methods: A total of 80 colorectal lesions were prospectively collected and removed by two novice operators. Before human ESD procedures, they received ESD training using an ex vivo porcine “proximal colon” model, which simulates a lumen with many folds and flexions. To assess the validity of our training system, the self-completion and en bloc R0 resection rates, the operation time, and prevalence of complications were compared between the first and latter period. Moreover the factors associated with prolonged operation time were evaluated. Results: The overall rates of self-completion and en bloc R0 resection were 98 % (78/80) and 100 % (80/80), respectively. The operation time during the first period was significantly longer than that during the latter period (86 ± 50 minutes vs. 60 ± 36 minutes, P = 0.01). Regarding complications, only two cases of perforations and delayed hemorrhage were observed during the first period; however, all of the complications were successfully managed endoscopically. The presence of fibrosis was identified as a significant independent predictor of a prolonged operation time during the first period (coefficient, 5.90; 95 %CI, 2.36 – 9.44, P = 0.002). Conclusions: Our trainees achieved high rates of self-completion and R0 resection without severe complications even during the first 20 cases, suggesting that our training programs using ex vivo animal models are useful for trainees without gastric ESD experience.Study registration: UMIN000013566

Background. Superficial duodenal neoplasms (SDNs) are a challenging target in the digestive tract. Surgical resection is invasive, and it is difficult to determine the site and extent of the lesion from outside the intestine and resect it locally. Endoscopic submucosal dissection (ESD) has scarcely been utilized in the treatment of duodenal tumors because of technical difficulties and possible delayed perforation due to the action of digestive juices. Thus, no standard treatments for SDNs have been established. To challenge this issue, we elaborated endoscopy-assisted laparoscopic full-thickness resection (EALFTR) and analyzed its feasibility and safety. Methods. Twenty-four SDNs in 22 consecutive patients treated by EALFTR between January 2011 and July 2012 were analyzed retrospectively. Results. All lesions were removed en bloc. The lateral and vertical margins of the specimens were negative for tumor cells in all cases. The mean sizes of the resected specimens and lesions were 28.9 mm (SD ± 10.5) and 13.3 mm (SD ± 11.6), respectively. The mean operation time and intraoperative estimated blood loss were 133 min (SD ± 45.2) and 16 ml (SD ± 21.1), respectively. Anastomotic leakage occurred in three patients (13.6%) postoperatively, but all were minor leakage and recovered conservatively. Anastomotic stenosis or bleeding did not occur. Conclusions. EALFTR can be a safe and minimally invasive treatment option for SDNs. However, the number of cases in this study was small, and further accumulations of cases and investigation are necessary.

Background and study aims This study aimed to investigate the diagnostic accuracy and utility of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) performed using a Franseen needle on solid pancreatic lesions. Patients and methods This study included 132 consecutive lesions sampled by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) using a 22-G conventional needle and 95 consecutive lesions evaluated by EUS-FNB using a 22-G Franseen needle to evaluate solid pancreatic lesions at our medical center between July 2013 and November 2018. We used propensity-matched analysis with adjustment for confounders. Patient data were analyzed retrospectively. Results Diagnostic accuracy was higher in the Franseen needle group (Group F; 91.6 %, 87 /95) than in the conventional needle group (Group C; 86.3 %, 82 /95), showing no significant difference (P = 0.36). In Group F, diagnostic accuracies for pancreatic head lesions and lesions sampled by transduodenal puncture were 98.0 % (48/49) and 97.9 % (46/47), respectively. These values were significantly higher than values in Group C (P = 0.013, 0.01). Group F displayed a significantly lower number of punctures. In terms of differentiating benign from malignant lesions, Group C showed 85.1 % sensitivity (74/87), 100 % specificity (8/8), 100 % positive predictive value (74/74), and 38.1 % negative predictive value (8/21), compared to values of 90.1 % (73/81), 100 % (14/14), 100 % (73/73), and 63.6 % (14/22), respectively, in Group F. Sensitivity and negative predictive value were better in Group F. Conclusions Franseen needles for EUS-FNB of solid pancreatic lesions offer similar puncture performance at different lesion sites while requiring fewer punctures than conventional needles.

The diagnostic process for biliary strictures remains challenging in some cases. A broad differential diagnosis exists for indeterminate biliary strictures, including benign or malignant lesions. The diagnosis of indeterminate biliary strictures requires a combination of physical examination, laboratory testing, imaging modalities, and endoscopic procedures. Despite the progress of less invasive imaging modalities such as transabdominal ultrasonography, computed tomography, and magnetic resonance imaging, endoscopy plays an essential role in the accurate diagnosis, including the histological diagnosis. Imaging findings and brush cytology and/or forceps biopsy under fluoroscopic guidance with endoscopic retrograde cholangiopancreatography (ERCP) are widely used as the gold standard for the diagnosis of biliary strictures. However, ERCP cannot provide an intraluminal view of the biliary lesion, and its outcomes are not satisfactory. Recently, peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound (EUS), and EUS-guided fine-needle aspiration have been reported as useful for indeterminate biliary strictures. Appropriate endoscopic modalities need to be selected according to the patient’s condition, the lesion, and the expertise of the endoscopist. The aim of this review article is to discuss the diagnostic process for indeterminate biliary strictures using endoscopy.