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Direct peroral cholangioscopy (POC) can be useful when combined with narrow-band imaging (NBI) to explore the etiologies of indeterminate biliary strictures. We evaluated the efficacy of NBI compared with that of conventional white-light imaging (WLI) during POC diagnosis of indeterminate biliary strictures.Consecutive patients with indeterminate biliary strictures were enrolled from 2016 to 2019. The primary outcome was diagnostic accuracy, and secondary outcomes were technical success, adverse events, and visualization quality when predicting malignancy.Seventy-one patients underwent direct POC under NBI during targeted biopsy sampling. The strictures were successfully explored and adequate biopsy samples obtained in 67 of 71 patients (94.4%). In terms of visual impression, WLI and NBI afforded 75.0% and 87.5% sensitivity, 82.9 and 91.4% specificity, and 82.8 and 91.3% accuracy, respectively. The areas under the WLI and NBI receiver-operating characteristic curves were .80 and .96 (P = .01). Under NBI, the visualization quality of surface structures, microvessels, and lesional margins was higher than that under conventional WLI (P .05).Direct POC under NBI effectively and accurately predicts malignancies of indeterminate biliary strictures. NBI effectively illuminated surface structures, microvessels, and lesional margins.

An electrocautery-enhanced delivery system with a lumen-apposing metal stent (LAMS) is available for one-step endoscopic ultrasound-guided transmural drainage (EUS-TD). Bipolar electrosurgery has several potential clinical advantages, including reduced collateral thermal damage, enhanced hemostasis, and no requirement for a return electrode plate. In this study, we compared the technical feasibility and safety of a newly developed bipolar electrocautery-enhanced delivery system with a conventional delivery system for EUS-TD using a LAMS in a porcine model.Ten days before the study, 12 mini pigs underwent common bile duct ligation for EUS-guided gallbladder drainage. Transenteric puncture was performed, followed by placement of a guidewire. In six pigs, a bipolar electrocautery-enhanced delivery system with LAMS (Hot SPAXUS) was inserted over the guidewire and advanced into the gallbladder, without prior dilation of the tract, by applying a bipolar cut current. In the remaining six pigs, a conventional delivery system with LAMS (Cold SPAXUS) was inserted after tract dilatation using a cystotome. The stent was removed after 4 weeks.In all pigs, the stent was successfully inserted and deployed in the gallbladder without adverse events. The mean procedure time of EUS-TD was significantly lower in the Hot SPAXUS group than that of the Cold SPAXUS group (mean ± standard deviation: 188.7 ± 5.2 vs 449.5 ± 97.5 s, P = .0019). Stent migration was not observed, and all stents were removed successfully.Endoscopic ultrasound-guided transmural drainage using a bipolar electrocautery-enhanced LAMS is feasible for reducing the procedure time while maintaining the high success rate and safety of conventional LAMS.

BACKGROUND AND AIM Durable biliary drainage is essential in patients with pancreatic cancer in the era of effective neoadjuvant chemotherapy (NACT). Plastic stent (PS) tends to occlude easily, and current metal stents are designed for nonresectable cancer. We evaluated the efficacy of a modified non-flared fully covered self-expandable metal stent (M-FCSEMS) during the perioperative period in patients with resectable or borderline resectable pancreatic cancer. METHODS Consecutive patients with resectable or borderline resectable pancreatic ductal adenocarcinoma had a 12-mm M-FCSEMS (M-FCSEMS group) or 7-Fr PS (PS group) placed for biliary decompression before NACT or curative-intent surgery. The primary outcome was the re-intervention rate, and secondary outcomes were technical success, stent patency, and adverse events (AEs). RESULTS Endoscopic stent placement was technically successful in all 60 patients. Twenty-three patients underwent surgery and 37 NACT before surgery. Re-intervention was performed in 10.0% (3/30) of patients in the M-FCSEMS group and 36.7% (11/30) of patients in the PS group (P = 0.030). The stent patency at 180 days was 89.8% (95% confidence interval, 77.3-100.0%) in the M-FCSEMS group and 30.2% (95% confidence interval, 11.4-80.0%) in the PS group (P

Background and Aims Although cholangiocarcinomas (CCAs) can be diagnosed using several modalities, the detection of early-stage cancers remains unsatisfactory. We explored whether peroral cholangioscopy (POC) could be used to screen for neoplastic bile duct lesions including CCAs in patients with bile duct stones. Methods Two hundred seven patients who underwent endoscopic removal of bile duct stones were enrolled between August 2010 and July 2018. The primary outcome was the detection rate of intraductal neoplastic biliary lesions by direct POC. Secondary outcomes were the technical success rates of direct POC and POC-guided forceps biopsy sampling (POC-FB), the diagnostic accuracy of the direct POC findings, adverse events, and the number needed to screen to detect a neoplastic bile duct lesion. Results Direct POC was successful in 199 of 207 patients (96.1%). Mild cholangitis developed in 2 patients (1.0%) and was treated conservatively. Of the 199 successfully performed POCs, 31 patients (15.6%) exhibited abnormal intraductal mucosal lesions. The technical success rate of POC-FB was 90.3% (28/31 patients). The pathologic diagnoses after POC-FB were CCAs (n = 4), intraductal papillary neoplasms of the bile duct (IPN-B) (n = 2), an adenoma with dysplasia (n = 1), and benign lesions (n = 21). Direct POC correctly distinguished non-neoplastic from neoplastic bile duct lesions in 91.6% of patients. Curative surgical resection was performed for the 5 patients with CCAs or IPN-B. The number needed to screen to detect a neoplastic bile duct lesion was 29.6. Conclusions Direct POC using a dedicated, ultraslim upper endoscope usefully screens for neoplastic bile duct lesions including CCAs in selected patients with bile duct stones.

Background/Aims: There are no definite guidelines for the management of gastric lesions diagnosed as indefinite for dysplasia (IND) by endoscopic forceps biopsy (EFB). Therefore, this study aimed to evaluate the clinical outcomes of gastric IND and predictive factors for gastric neoplasm.Methods: This study included 457 patients with a first diagnosis of gastric IND by EFB between January 2005 and December 2013. Patient characteristics and endoscopic and pathological data were reviewed and compared.Results: Of the 457 gastric IND patients, 128 (28%) were diagnosed with invasive carcinoma, 21 (4.6%) with high-grade dysplasia, 31 (6.8%) with low-grade dysplasia, and 277 (60.6%) as negative for dysplasia. Of lesions observed, 180 (39.4%) showed upgraded histology. Multivariate analysis revealed that surface erythema (odds ratio [OR], 2.804; 95% confidence interval [CI], 1.741 to 4.516), spontaneous bleeding (OR, 2.618; 95% CI, 1.298 to 5.279), lesion size ≥ 1 cm (OR, 5.762; 95% CI, 3.459 to 9.597), and depressed morphology (OR, 2.183; 95% CI, 1.155 to 4.124) were significant risk factors for high-grade dysplasia or adenocarcinoma. The ORs associated with 2 and ≥ 3 risk factors were 7.131 and 34.86, respectively.Conclusions: Precautions should be taken in the management of gastric IND patients, especially when risk factors, including surface erythema, spontaneous bleeding, lesion size ≥ 1 cm, and depressed morphology are present. Considering the combined effect of the presence of multiple risk factors on the incidence of high-grade dysplasia or adenocarcinoma, endoscopic resection should be recommended if a gastric IND patient has at two or more of these factors.

Endoscopic post-papillectomy bleeding is a serious adverse event with a prevalence ranging from 2% to 45.3%. Conventional hemostatic methods, including diluted epinephrine injection before papillectomy or argon plasma coagulation after papillectomy, did not show a preventive role in reducing immediate or delayed post-papillectomy bleeding. Therefore, we aimed to assess the efficacy and safety of a hemostatic powder spray for post-papillectomy bleeding and compare with those of conventional modalities.Patients who underwent endoscopic papillectomy were enrolled in five tertiary hospitals. The group was divided into hemostatic spray and conventional control groups according to the bleeding control methods. The main outcome measurements were delayed bleeding rate and any adverse events related to the procedures.A total of 40 patients who received a hemostatic spray (n = 18) or conventional hemostatic methods (n = 22) after endoscopic papillectomy were included. The prevalence of delayed bleeding was not different in the two groups: 27.8% and 36.4% in hemostatic spray and conventional control groups (P = 0.564), respectively. The adverse events such as post-papillectomy pancreatitis and cholangitis were not different in the two groups. There were no procedure-related mortalities.Hemostatic spray is technically feasible and safe for the prevention or management of post-papillectomy bleeding. Hemostatic spray can be one of the options for post-papillectomy bleeding control methods owing to its convenient use.

A clinical efficacy study of 0.025-inch guidewires (GWs) according to mechanical property analysis has not been reported yet. This study was designed to evaluate the clinical efficacy of a newly developed 0.025-inch GW for biliary access according to the basic mechanical property. Commercially available 0.025-inch GWs were in vitro tested based on parameters of mechanical property. Patients with naïve papilla requiring diagnostic or therapeutic ERCP were randomly assigned to an experimental 0.025-inch newly developed GW or a control 0.025-inch GW group. Technical success rate of wire-guided cannulation (WGC), difficult biliary cannulation (DBC), and adverse event rates were measured in this multicenter randomized trial. The technical success rate of primary WGC was 79.1% (151 of 191) in the experimental group and 70.8% (131 of 185) in the control group (95% two-sided confidence interval: 8.25%; pvs. 68.1%; p=0.002). Median biliary cannulation time was shorter in the experimental group (53 seconds vs. 77 seconds; p=0.047). The rate of DBC was more frequent in the control group (34.6 % vs. 50.3% p=0.002). Multivariate analysis revealed that control group was one of contributing factors for DBC. Overall rate of post-ERCP pancreatitis was not different (4.7% vs. 8.6%; p=0.125). WGC using a newly developed GW with superior physical performance GW in a bench test showed similar clinical efficacy and the rate of DBC was significantly lower in experimental GW.

Background Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumen-apposing metal stent (LAMS) has rendered endoscopic gallbladder assessment through a stent possible, but an appropriate endoscope is required. We assessed the feasibility of peroral cholecystoscopy (POCC) using a multibending ultraslim endoscope passed through a LAMS after EUS-GBD. Methods 14 patients with a LAMS for EUS-GBD who consecutively underwent POCC were included. POCC was performed using a multibending endoscope inserted through the LAMS. The primary outcome was the technical success rate, defined as complete endoscopic examination of the gallbladder from the orifice of the cystic duct to the fundus. The types of intervention and adverse events were recorded. Results 17 POCCs were performed in 14 patients. Of the 17 POCCs, 15 (88.2 %) were technically successful. Narrow-band imaging endoscopy was performed in 12 procedures (70.6 %), and cholecystoscopy-guided target biopsies were obtained in six. Gallstone extraction was performed in two patients. After POCC, all LAMSs remained stable and no adverse events were observed. Conclusions POCC using a multibending ultraslim endoscope can be effectively and safely performed through a LAMS after EUS-GBD.

The detection of residual or fragmented common bile duct (CBD) stones after lithotripsy can be improved by the high-resolution imaging quality of digital, single-operator cholangioscopy (SOC). However, therapeutic interventions for the removal of residual CBD stones are limited by the lack of appropriate tools. We retrospectively evaluated the role of SOC and the newly developed Dormia basket for the evaluation and removal of stones remaining after lithotripsy. Thirty-four patients who had undergone lithotripsy for retained CBD stones with no evidence of filling defects in occluded balloon cholangiography from March 2017 to October 2018 were included in the study. After balloon cholangiography, the bile duct was evaluated by SOC for complete evacuation of the stones. The detected residual CBD stones were directly retrieved by inserting the newly developed Dormia basket into the working channel of the SOC. The incidence of residual stones detected by SOC and the success rate of residual stone retrieval by SOC were investigated. Digital SOC was successfully performed in all patients. Of these, 11 patients (32.4%) had residual CBD stones. The residual stones were successfully removed in 10 patients (90.9%) by SOC using the Dormia basket, except in one case of residual stones left in the hepatic duct. There were no adverse events associated with the SOC procedures or direct stone removal. Digital SOC combined with the newly developed Dormia basket was useful for the detection and extraction of residual CBD stones under direct visualization after lithotripsy.

Compared with currently available duodenoscopy-assisted systems, direct peroral cholangioscopy (DPOC) using an ultra-slim endoscope is limited by technical difficulties. The multibending (MB) ultra-slim endoscope was introduced as a dedicated cholangioscope for DPOC to challenge the technical problem. We retrospectively analyzed the clinical utility of DPOC using an MB endoscope with free-hand insertion into the bile duct in patients with biliary diseases.A total of 145 patients who underwent DPOC using an MB endoscope were analyzed. The primary outcome was the technical success rate of DPOC using the free-hand insertion of the MB endoscope. The secondary outcomes were the technical success rates of DPOC-guided diagnostic and therapeutic interventions, the diagnostic accuracy of DPOC-guided target biopsy, and adverse events related to DPOC.Free-hand biliary insertion of a MB endoscope for DPOC was technically successful in 133 patients (91.7%). DPOC-guided target biopsy was successful in 36 of 38 patients (94.7%) and had a diagnostic accuracy of 91.7% (95% confidence interval, 82.6-100). Sixty-nine therapeutic interventions were performed; technical success was achieved in 65 (94.2%). No severe adverse events were observed.The MB ultra-slim endoscope was technically effective to perform a DPOC including various diagnosis and therapeutic interventions without device assistance. MB endoscope is considered to contribute to expanding a role of DPOC in diagnosis and treatment of diverse biliary tract diseases.

Backgrounds and aim Multiple insertions of self-expandable metal stents (SEMS) for advanced malignant hilar obstruction (MHO) are now considered to be an effective palliative method for adequate drainage of liver volume. However, the efficacy of endoscopic reintervention in technically and clinically successful bilateral SEMS is limited. This study investigated the endoscopic revision efficacy in patients who underwent bilateral SEMS in MHO. Methods Primary endoscopic revision using plastic or metal stents or an alternative percutaneous approach followed by secondary endoscopic revision was performed in patients who underwent clinically successful deployment of bilateral SEMS. The primary outcome was a technical success. Secondary outcomes were clinical success, adverse events, and patency duration after reintervention. Results A total of 55 patients (83.3%) out of 66 enrolled patients underwent reintervention: primary endoscopic reintervention (n = 47) and secondary endoscopic revision following percutaneous drainage (n = 8). Intended technical success rates of primary and secondary endoscopic reintervention were 93.6% (44/47) and 87.5% (7/8), respectively (P = 0.47). Clinical success rates were 72.3% and 50%, respectively (P = 0.23). Stent malfunction rate after reintervention was 48.9% (23/47) and 37.5% (3/8) (P = 0.70) during follow up, and median cumulative stent patency duration was 119 and 55 days, respectively (log-rank P = 0.68). Stent patent rate after reintervention was not different according to the time interval. In univariate and multivariate analysis for stent patency duration-related factors after reintervention, there were no meaningful factors. Conclusion Primary endoscopic reintervention for bilateral SEMS in MHO was feasible technically and clinically. However, there were no statistically meaningful factors for stent patency duration after reintervention.

Endoscopic ultrasound (EUS) guided choledochoduodenostomy using a lumen-apposing metal stent (LAMS) allows access to the biliary system with a sufficiently large diameter stent. However, an appropriate endoscope for this purpose is required. We evaluated the feasibility of per-oral cholangioscopy (POC) using a multibending ultra-slim endoscope through a LAMS for EUS-guided choledochoduodenostomy.Twelve patients who underwent EUS-guided choledochoduodenostomy, followed by POC via a LAMS, were enrolled. POC was performed with an multibending ultra-slim endoscope. The primary outcome was technical success, defined as examination of both hepatic ducts and either the distal common bile duct or stricture site within 10 min. The types of intervention and adverse events were also assessed.Technical success was achieved in all cases with the multibending ultra-slim endoscope. Narrow-band imaging endoscopy was performed in five cases (41.7%) and POC-guided targeted biopsy was performed in three cases (25.0%). Stone extraction during POC was performed in two patients (16.7%) and foreign body removal from the intrahepatic duct was performed in one patient. One patient underwent additional metal stent insertion under direct visualization. After POC, no stent migration or severe adverse events were seen in any case.POC using a multibending ultra-slim endoscope for diagnostic or therapeutic purposes can be performed effectively and safely through a LAMS after EUS-guided choledochoduodenostomy.

The therapeutic utility of peroral cholangioscopy (POC) is limited. Direct POC using an ultra‑slim upper endoscope expands the therapeutic indications because of its larger working channel, of up to 2.2 mm. We evaluated the feasibility of selective biliary drainage using a plastic stent under direct POC. From April 2015 to March 2019, biliary drainage under endoscopic visualization was performed in the same endoscopic session as direct POC without exchanging the duodenoscope. After guidewire insertion through the stricture or stone, a 5 Fr plastic stent and/or nasobiliary drainage catheter was used for biliary drainage. Selective biliary drainage under direct POC was performed in 32 patients, including 17 with difficult bile duct stones. Biliary drainage was performed with a plastic stent in 29 patients, nasobiliary drainage in one, and combined drainage in two patients. The technical success rate for biliary drainage placement under direct POC was 100 % (32/32). No significant procedure-related complications occurred. In conclusion, biliary drainage with a plastic stent or catheter under direct POC using an ultra-slim upper endoscope is feasible and may be useful for lesions obstructing the bile duct.

BACKGROUND AND AIM Fully covered self-expandable metal stents (FCSEMS) may be better than plastic stents (PS) for preoperative biliary drainage (PBD) to relieve cholangitis or jaundice for resectable malignant biliary obstruction (MBO). However, modification of current FCSEMS designed originally for nonresectable MBO is needed to be a proper stent for PBD. The aim of this study was to evaluate the possible superiority of non-flared modified FCSEMS (M-FCSEMS) with 12-mm diameter and waist of central portion over PS in patients with resectable MBO. METHODS Eighty-five consecutive patients underwent PBD followed by operation from August 2015 to December 2017. In each M-FCSEMS and PS group, 29 patients were matched for age, sex, body mass index, and preoperative albumin and bilirubin levels. RESULTS The overall technical success rates of PBD using M-FCSEMS and PS were 100%. The time to operation was similar between groups (18.6 ± 10.8 vs 19.3 ± 11.6 days, respectively; P = 0.843). The prevalence of PBD-related adverse events (AEs) was 6.9% (2/29) in the M-FCSEMS group versus 27.6% (8/29) in the PS group (P = 0.037). Re-intervention before operation was required in 20.7% (6/29) of patients in the PS group but no patients in the M-FCSEMS group (P = 0.023). No differences were found between perioperative AEs in the M-FCSEMS and PS groups (27.5% vs 31.0%, respectively; P = 0.773). CONCLUSION Modified FCSEMS led to lower PBD-related AEs, re-intervention rate, and comparable perioperative AEs compared with PS. M-FCSEMS may be a potential novel stent for PBD in patients with resectable MBO.

Backgrounds Fully covered self-expandable metal stent (FCSEMS) are preferred for distal malignant biliary stricture (MBS). However, stent migration is a major adverse event of FCSEMS, especially for far distal MBS. We evaluated the usefulness of newly modified FCSEMS (M-FCSEMS) having 12 mm in diameter and anti-migration feature to minimize stent migration compared with the conventional FCSEMS (C-FCSEMS). Methods Total 102 patients were enrolled between January 2015 and September 2017 in this prospective comparative study; 50 were allocated to the M-FCSEMS group and 52 to the C-FCSEMS group. The primary outcome was stent migration, and the secondary outcomes were other adverse events, stent occlusion rate, and stent patency during the follow-up period. Results The baseline characteristics of the two groups did not significantly differ. Endoscopic stent placement was technically successful in all patients. Stent migration occurred in 8.0% (4/50) of the patients in the M-FCSEMS group and 23.1% (12/52) of those in the C-FCSEMS group (P = 0.036). The other adverse events, including stent-related pancreatitis and cholecystitis did not significantly differ between the two groups (P = 0.415). Stent occlusion occurred in 23.9% (11/46) of the patients in the M-FCSEMS group and 37.5% (15/40) in the C-FCSEMS group (P = 0.171). Stent patency was significantly longer in the M-FCSEMS group than in the C-FCSEMS group (228 vs 157 days, P = 0.048). Conclusions Modified FCSEMS with 12-mm diameter and anti-migration feature significantly decreased the risk of stent migration and had longer patency compared with C-FCSEMS in patients with periampullary MBS.

The factors associated with recurrence of colonic neoplasm after endoscopic resection with a positive lateral margin are not well known. Thus, we evaluate the relationship between recurrence and positive lateral margin after endoscopic en bloc resection of colorectal neoplasm.A retrospective review of 9302 patients who underwent colonic endoscopic resection from January 2008 to January 2015. Of these, a total of 76 patients with positive lateral margins with clear evidence of the its location on endoscopic picture after endoscopic en bloc resection of colorectal neoplasm (10 mm) were included.Ten of 76 (13.2%) patients experienced recurrence during the follow-up period (mean f/u month, 21.7 ± 15.6). In cases with positive lateral margins, the 3- and 5-year local recurrence rate of colorectal neoplasm was 28.1% and 40.1%, respectively. The histological features of the recurrence group were as follows: one case of adenocarcinoma [from low-grade adenoma (LGA)]; two cases of high-grade adenoma (HGA) (one from HGA and one from LGA); and seven cases of LGA (four from adenocarcinoma, two from LGA, and one from HGA). The mean age of patients, locations of the lesions, and histologic type were not significantly associated with local recurrence. In multivariate Poisson regression analyses, total length of lateral margin involvement ≥8 mm (relative risk 12.51; 95% CI 1.11-140.34, p = .040) was a significant predictor of local recurrence.Positive lateral margins ≥8 mm may be a reliable predictor of local recurrence after endoscopic en bloc resection of colorectal neoplasm.

Background The use of a lumen-apposing metal stent (LAMS) capable of one-step endoscopic ultrasound-guided transmural drainage (EUS-TD) can increase the effectiveness of the procedure. We evaluated the newly developed electrocautery-enhanced (EC) delivery system with a LAMS for one-step EUS-guided gallbladder drainage (EUS-GBD) or choledochoduodenostomy (EUS-CDS). Methods In the animal experiment, an EC-LAMS was advanced into the gallbladder without prior tract dilation in four pigs. A conventional LAMS was inserted in another four pigs as a control group. After the animal experiment, 17 patients underwent EUS-TD using the EC-LAMS (EUS-GBD in 10 patients, EUS-CDS in 7). The primary outcome was the technical success rate. Results In the animal study, the mean procedure time was significantly shorter in the EC-LAMS group than in the conventional LAMS group. In the human study, the overall technical success rate was 94.1 %, with one EUS-GBD failure. The clinical success rate was 100 %. The overall adverse event rate was 17.6 %. Conclusions One-step EUS-GBD or EUS-CDS using the novel EC-LAMS is a feasible approach that achieves a high success rate and maintains safety.

There is no clear data to compare the effectiveness and safety of bilateral stent-in-stent (SIS) or stent-by-stent (SBS) deployment for advanced malignant hilar obstruction (MHO). This meta-analysis was done to investigate clinical outcomes of these deployment methods.We did a literature search to identify studies that reported the clinical outcomes of bilateral metal stents in patients with advanced MHO. Weighed pooled rates (WPR) along with 95% confidence interval (95% CI) were calculated in order to compare outcomes including technical and clinical success, adverse events, and stent occlusion between the two groups. We conducted a meta-analysis using a random-effects model.Five comparative studies with 250 patients, and 20 single-arm studies for the SIS or SBS method were eligible for the meta-analysis and systematic review. The bilateral SIS deployment had a significantly higher technical success rate than did SBS deployment (OR 6.43; 95% CI 1.08-38.09). There was no difference in the clinical success (OR 1.23; 95% CI 0.45-3.38), overall adverse events rates (OR 0.42; 95% CI 0.15-1.18), or overall occlusion rate (OR 1.55; 95% CI 0.89-2.70). As a single-armed group, WPR of technical success of the SIS and SBS groups was 96.4% and 89.6%, respectively. Clinical success was 97.5% and 98.3%. Overall, adverse events were 35.9% and 22.6%. Occlusion rates were 27.7% and 37.7%.Although there was a lack of quality data and heterogeneity, bilateral SIS deployment had a higher technical feasibility than did the SBS method in patients with advanced MHO, without differences in terms of clinical success, adverse events, or occlusion rates.

Background and aim Endoscopic management of a benign biliary stricture (BBS) on the hilum is complicated and challenging. Although the placement of a fully covered self-expandable metal stent (FCSEMS) is possible to increase effectiveness, stent migration and stent-induced adverse events are problematic. We aimed to evaluate the usefulness of a modified short FCSEMS with a long lasso in patients with a difficult perihilar BBS. Methods Patients with perihilar BBS within 2 cm from the hilar confluence that failed initially with plastic stents were enrolled. A modified short FCSEMS was deployed and then removed 5-6 months later. The primary outcome was clinical success. Other technical success, adverse events, endoscopic success of stent removal, and recurrence of stricture during the follow-up period were measured. Results Endoscopic intraductal placement was technically successful in all patients (n = 19). Combined contralateral plastic stent placement was performed in 13 patients (68.4%). The median duration of stent placement was 163 days (range, 138-196 days). Endoscopic stent removal was successful in all patients except one spontaneous distal migration. Stricture resolution without de novo focal stricture occurrence was 100%. Endoscopic stone removal after stricture improvement was successful in all 13 patients with bile duct stones above the stricture. During a follow-up period (median 635 days) after stent removal, only one recurrence developed. Conclusions Temporary placement of a modified intraductal short FCSEMS with or without a contralateral plastic stent improved perihilar BBS in patients that primarily failed by plastic stents. Combined biliary stones were also successfully removed after stricture resolution.

Background and aim Endoscopic post-papillectomy bleeding occurs in 3% to 20% of the cases, and delayed bleeding is also problematic. However, there is no consensus on how to reduce delayed post-papillectomy bleeding. The aim of this study was to evaluate the efficacy of prophylactic argon plasma coagulation (APC) to minimize delayed bleeding and reduce the persistence of residual tumors after endoscopic papillectomy. Methods In a prospective pilot study of patients with benign ampullary tumors, the prophylactic APC group underwent APC at the resection margin following a conventional snaring papillectomy. Then, 24 h later after the papillectomy, all patients underwent a follow-up duodenoscopy to identify post-papillectomy bleeding and were followed up until 12 months. The main outcomes were the delayed (≥24 h) post-papillectomy bleeding rate and the tumor persistence rate. Results The delayed post-papillectomy bleeding rate was 30.8% (8/26) in the prophylactic APC group and 21.4% (6/28) in the non-APC group (P = 0.434). The post-procedure pancreatitis rates were 23.1% (6/26) and 35.7% (10/28), respectively (P = 0.310). The rate of tumor persistence did not differ between the two groups at 1 month (12.5% vs 7.4%, P = 0.656), 3 months (4.2% vs 3.7%, P = 1.00), 6 months (8.3% vs 3.7%, P = 0.595), and 12 months (0% vs 3.7%, P = 1.00). There were no procedure-related mortalities or serious complications. Conclusion Prophylactic APC may not be effective in reducing delayed post-papillectomy bleeding or remnant tumor ablation immediately after conventional papillectomy (Clinical trial registration-cris.nih.go.kr; KCT0001955).

Background Although endoscopic retrograde cholangiopancreatography (ERCP) is a first-line diagnostic modality for suspected malignant biliary stricture (MBS), the diagnostic yield of ERCP-based tissue sampling is insufficient. Peroral cholangioscopy-guided forceps biopsy (POC-FB) and endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) are evolving as reliable diagnostic procedures for inconclusive MBS. This study aimed to evaluate the usefulness of a diagnostic approach using POC-FB or EUS-FNAB according to the stricture location in patients with suspected MBS. Methods Consecutive patients diagnosed with suspected MBS with obstructive jaundice and/or cholangitis were enrolled prospectively. ERCP with transpapillary forceps biopsy (TPB) was performed initially. When malignancy was not confirmed by TPB, POC-FB using a SpyGlass direct visualization system or direct POC using an ultraslim endoscope was performed for proximal strictures, and EUS-FNAB was performed for distal strictures as a follow-up biopsy. Results Among a total of 181 patients, initial TPB showed malignancy in 122 patients, and the diagnostic accuracy of initial TPB was 71.8 % (95 % confidence interval [CI] 65.3 % – 78.4 %]. Of the 59 patients in whom TPB was negative for malignancy, 32 had proximal biliary strictures and underwent successful POC. The remaining 27 patients had distal strictures and underwent successful EUS-FNAB. The accuracy of malignancy detection using POC-FB for proximal biliary strictures and EUS-FNAB for distal biliary strictures was 93.6 % (95 %CI 84.9 %−100 %) and 96.3 % (95 %CI 89.2 %−100 %), respectively. The overall diagnostic accuracy for the combination of TPB with either POC-FB for proximal strictures and EUS-FNAB for distal strictures was 98.3 % (95 %CI 95.9 %−100 %) and 98.4 % (95 %CI 95.3 %−100 %), respectively. Conclusions An approach using POC-FB or EUS-FNAB according to the stricture location may be useful in the diagnosis of suspected MBS.

Background/Aims In suspected malignant biliary strictures (MBSs), the diagnostic yield of endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling is limited. Transpapillary forceps biopsy (TPB) under intraductal ultrasonography (IDUS) guidance is expected to improve the diagnostic accuracy in patients with indeterminate biliary strictures. We evaluated the usefulness of IDUS-guided TPB in patients with suspected MBS. Methods Consecutive patients with suspected MBS were prospectively enrolled in the study. ERCP with IDUS was performed in all patients. Both conventional TPB and IDUS-guided TPB on fluoroscopy were performed in each patient. The primary outcome was the diagnostic accuracy of conventional TPB and IDUS-guided TPB. Results The technical success rate of IDUS-guided TPB was 97.0% (65/67 patients). Of these 65 patients, the final diagnosis was malignancy in 61 patients (93.8%). On IDUS, the most common finding of IDUS was an intraductal infiltrating lesion in 29 patients (47.5%). The overall diagnostic accuracy was significantly higher using IDUS-guided TPB than that using conventional TPB (90.8% vs 76.9%, p=0.027). According to the subgroup analysis based on the tumor morphology, IDUS-guided TPB had a significantly higher cancer detection rate than conventional TPB for intraductal infiltrating lesions (89.6% vs 65.5%, p=0.028). Conclusions IDUS-guided TPB appears to improve the accuracy of histological diagnosis in patients with MBS.

Background and Aims The efficacy of palliative biliary drainage by using bilateral or unilateral self-expandable metal stents (SEMSs) for a malignant hilar biliary stricture (MHS) remains controversial. This prospective, randomized, multicenter study investigated whether bilateral drainage by using SEMSs is superior to unilateral drainage in patients with inoperable MHSs. Methods Patients with inoperable high-grade MHSs who underwent palliative endoscopic insertion of bilateral or unilateral SEMSs were enrolled. The main outcome measurements were the rate of primary reintervention for malfunction after successful placement of SEMSs, stent patency, technical and clinical success rates, adverse events, and survival duration. Results A total of 133 pathology-diagnosed patients were randomized to the bilateral group (n = 67) or the unilateral group (n = 66). The primary technical success rates were 95.5% (64/67) and 100% (66/66) in the bilateral and unilateral groups, respectively ( P = .244). The clinical success rates were 95.3% (61/64) and 84.9% (56/66), respectively ( P = .047). The primary reintervention rates based on the per-protocol analysis were 42.6% (26/61) in the bilateral group and 60.3% (38/63) in the unilateral group ( P = .049). The median cumulative stent patency duration was 252 days in the bilateral group and 139 days in the unilateral group. The risk of stent patency failure was significantly higher in the unilateral group (log-rank test; P P Conclusions Unilateral and bilateral drainage strategies by using SEMSs had similar technical success rates, but bilateral drainage resulted in fewer reinterventions and more durable stent patency in patients with inoperable high-grade MHSs. (Clinical trial registration number: NCT02166970.)

Background/Aims Treatment for cholangitis without common bile duct (CBD) stones has not been established in patients with gallstones. We investigated the usefulness of endoscopic biliary drainage (EBD) without endoscopic sphincterotomy (EST) in patients diagnosed with gallstones and cholangitis without CBD stones by endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS). Methods EBD using 5F plastic stents without EST was performed prospectively in patients with gallstones and cholangitis if CBD stones were not diagnosed by ERCP and IDUS. After ERCP, all patients underwent laparoscopic cholecystectomy. The primary outcomes were clinical and technical success. The secondary outcomes were recurrence rate of biliary events and procedure-related adverse events. Results Among 187 patients with gallstones and cholangitis, 27 patients without CBD stones according to ERCP and IDUS received EBD using 5F plastic stents without EST. The stents were maintained in all patients until laparoscopic cholecystectomy, and recurrence of cholangitis was not observed. After cholecystectomy, the stents were removed spontaneously in 12 patients and endoscopically in 15 patients. Recurrence of CBD stones was not detected during the follow-up period (median, 421 days). Conclusions EBD using 5F plastic stents without EST may be safe and effective for the management of cholangitis accompanied by gallstones in patients without CBD stones according to ERCP and IDUS.

Background and Aims Whether or not submucosal injection of a diluted epinephrine solution should be used to lift ampullary tumors during endoscopic snare papillectomy is unclear. This study aimed to investigate the clinical efficacy of a simple snaring method versus submucosal injection for papillectomy. Methods A prospective multicenter study was performed at 4 tertiary referral centers. Patients with papillary lesions were randomized to undergo either simple snare papillectomy (SSP) or submucosal injection papillectomy (SIP) using 1:10,000 diluted epinephrine. The main outcome measures were complete resection rate and post-papillectomy adverse events. Results A total of 50 patients with biopsy-proven papillary adenomas were enrolled. Complete resection rates in the SSP and SIP groups were 80.8% (21/26) and 50.0% (12/24), respectively ( P = .02). However, tumor persistence at 1 month (15.4% vs 8.3%, P = .62) and recurrence at 12 months (12.0% vs 9.5%, P = .58) did not differ despite initial differences in the prevalence of a positive resection margin. The mean tumor size was 12 mm in the SSP group and 9.29 mm in the SIP group. Post-papillectomy bleeding developed in 42.3% (11/26) and 45.8% (11/24) of patients, respectively ( P = .80). Delayed bleeding (>12 h) occurred in 27.3% (3/11) and 36.4% (4/11) of patients, respectively ( P = .50). Post-procedure pancreatitis occurred in 15.4% (4/26) and 25% (6/24) of patients, respectively ( P = .49). Pancreatitis severity did not differ between the groups, and there were no procedure-related mortalities. Conclusions Although the recurrence rate was similar between the SSP and SIP groups, SIP showed no advantage over SSP in terms of achieving complete resection or decreasing the frequency of post-papillectomy adverse events, such as bleeding. SSP may thus be a simpler and primarily recommendable technique. (Clinical trial registration number: NCT02165852.)

Background and Aim As society ages, the need for endoscopic retrograde cholangiopancreatography (ERCP) is increasing. This prospective comparative study evaluated the safety and efficacy of midazolam- versus propofol-based sedations by non-anesthesiologists during therapeutic ERCP in patients over 80 years of age. Methods A total of 100 patients over 80 years of age who required therapeutic ERCP were enrolled and randomly received midazolam + fentanyl (MF group) or propofol + fentanyl (PF group) sedation. Endoscopic sedation was titrated to a moderate level and carried out by trained registered nurses. Main outcome measurements were sedation safety in terms of cardiopulmonary components and efficacy measured on a 10-point visual analogue scale (VAS). Results Regarding safety, hypoxia occurred in seven (14%) in the MF group and in eight patients (16%) in the PF group (P = 0.779). Increased O2 supply was more frequent in the PF group (32% vs 42%), albeit not significantly so. There were no differences in the frequency of hypotension, bradycardia or tachycardia between the two groups. Mean VAS score for overall satisfaction with sedation by patients, endoscopists, and nurses and the scores for pain during the procedures were not different between the two groups. There was no significant difference in the procedure outcomes or rate of ERCP-related complications. Conclusions There were no significant differences of safety and efficacy between midazolam- and propofol-based sedation in patients over 80 years of age. Increased O2 supply was more frequent in the propofol group, but the prevalence of hypoxia did not differ significantly.

In malignant biliary stricture (MBS), the diagnostic accuracy of ERCP‐based tissue sampling is insufficient. EUS‐guided fine needle aspiration biopsy (EUS‐FNAB) is emerging as a reliable diagnostic procedure. This study aimed to evaluate the usefulness of a diagnostic approach using ERCP‐guided transpapillary forceps biopsy (TPB) or EUS‐FNAB according to the characteristics of suspected MBS. Consecutive patients diagnosed with suspected MBS with obstructive jaundice and/or cholangitis were enrolled prospectively. ERCP with intraductal ultrasonography (IDUS) and TPB were performed as initial diagnostic procedures. Based on the results of imaging studies and IDUS, all MBS were classified as extrinsic or intrinsic type. If the malignancy was not confirmed by TPB, EUS‐FNAB for extrinsic type or second TPB for intrinsic type was performed. Among a total of 178 patients, intrinsic and extrinsic types were detected in 88 and 90 patients, respectively. The diagnostic accuracy of first TPB was significantly higher in the intrinsic than in the extrinsic type (81.8% vs. 67.8, P = 0.023). In 33 patients with extrinsic type and negative for malignancy on first TPB, the diagnostic accuracy of EUS‐FNAB was 90.9%. In 19 patients with intrinsic type and negative for malignancy on first TPB, the diagnostic accuracy of second TPB was 84.2%. The diagnostic accuracies of the combination of initial TPB with EUS‐FNAB and second TPB were 96.7% and 96.6%, respectively. A diagnostic approach using EUS‐FNAB or TPB according to the origin of MBS is considered effective to improve the diagnostic accuracy of MBS with negative for malignancy on first TPB. (Clinical trial registration number: UMIN000016886).

Background/Aims Controversy still exists regarding the benefits of covered self-expandable metal stents (SEMSs) compared to uncovered SEMSs. We aimed to compare the patency and stent-related adverse events of partially covered SEMSs (PC-SEMSs) and uncovered SEMSs in unresectable malignant distal biliary obstruction. Methods A total of 134 patients who received a PC-SEMS or uncovered SEMS for palliation of unresectable malignant distal biliary obstruction were reviewed retrospectively. The main outcome measures were stent patency, stent-related adverse events, and overall survival. Results The median stent patency was 118 days (range, 3 to 802 days) with PC-SEMSs and 105 days (range, 2 to 485 days) with uncovered SEMSs (p=0.718). The overall endoscopic revision rate due to stent dysfunction was 36.6% (26/71) with PC-SEMSs and 36.5% (23/63) with uncovered SEMSs (p=0.589). Tumor ingrowth was more frequent with uncovered SEMSs (4.2% vs 19.1%, p=0.013), but migration was more frequent with PC-SEMSs (11.2% vs 1.5%, p=0.04). The incidence of stent-related adverse events was 2.8% (2/71) with PC-SEMSs and 9.5% (6/63) with uncovered SEMSs (p=0.224). The median overall survival was 166 days with PC-SEMSs and 168 days with uncovered SEMSs (p=0.189). Conclusions Compared to uncovered SEMSs, PC-SEMSs did not prolong stent patency in unresectable malignant distal biliary obstruction. Stent migration was more frequent with PC-SEMSs. However, tumor ingrowth was less frequent with PC-SEMSs compared to uncovered SEMSs.

Background and Aim KRAS mutation analysis may provide ancillary diagnostic yield in an endoscopic ultrasound (EUS)-guided histopathological evaluation. We evaluated the clinical impact of KRAS mutation analysis with cytological and histological evaluations in EUS-guided tissue sampling, using a core biopsy needle for solid liver masses. Methods EUS-guided fine needle biopsy (EUS-FNB) using a core biopsy needle was performed in patients with primary or metastatic liver masses that were suspected malignancies. KRAS mutations were analyzed in all specimens obtained. The peptide nucleic acid (PNA)-mediated polymerase chain reaction (PCR) clamping method was compared with a next-generation sequencing (NGS) method for detecting KRAS mutations. Results EUS-FNB with a core biopsy needle was performed in 28 patients with solid liver masses located in the liver's left lobe. The diagnostic accuracies for malignancy of on-site cytology, cytology using Papanicolaou staining, and histology including immunohistochemical stains were 82.1%, 85.7%, and 89.3%, respectively. KRAS gene mutations were observed in 14.3% of patients by the PNA-PCR clamping method. The NGS method detected more KRAS mutations than the PNA-PCR clamping method: in 25% of patients. Adding the results of KRAS mutation analysis to the cytohistopathological evaluation, the overall diagnostic accuracy of EUS-guided tissue sampling was 96.4%. Conclusions EUS-guided tissue sampling for solid liver masses in the left lobe provided high diagnostic accuracy from cytological and histological evaluations. KRAS mutation analysis provided additional diagnostic yield in patients with inconclusive cytohistopathological results from EUS-guided tissue sampling. The NGS method detected additional KRAS mutations in patients with negative PNA-mediated PCR clamping test results.