Prospective randomized trial of a new multibending versus conventional ultra-slim endoscope for peroral cholangioscopy without device or endoscope assistance (with video).

BACKGROUND AND AIMS: Currently available peroral cholangioscopy (POC) is a duodenoscopy-assisted procedure that does not involve directly inserting an endoscope into the biliary tree. A prototype multibending (MB) ultra-slim endoscope has been developed as a dedicated cholangioscope to overcome the technical difficulties of direct POC. In this study, we evaluated the efficacy of the new MB ultra-slim endoscope compared with a conventional ultra-slim endoscope for free-hand insertion of an endoscope into the bile duct for direct POC without the assistance of accessories. METHODS: Ninety-two patients with biliary disease requiring diagnostic and/or therapeutic direct POC were assigned randomly to groups examined using an MB ultra-slim endoscope (MB group, n=46) versus a conventional ultra-slim endoscope (conventional group, n=46). The primary outcome was the technical success of free-hand insertion of the endoscope during direct POC, defined as successful insertion of the endoscope through the ampulla of Vater and advancement of the endoscope up to the bifurcation or to the obstructed segment of the biliary tree without any accessories within 15 minutes. RESULTS: Free-hand biliary insertion of the endoscope for direct POC was technically successful in 41 patients (89.1%) in the MB group, which was significantly higher than the rate (14 patients, 30.4%) in the conventional group (P < .001). The procedure time (mean ± standard deviation) of direct POC using free-hand biliary insertion of the endoscope was significantly shorter in the MB group than in the conventional group (3.2 ± 1.8 vs 6.0 ± 3.0 minutes, P = .004). Adverse events were observed in 3 patients (6.5%) in the MB group and 2 patients (4.3%) in the conventional group (P = .500), all of whom were treated conservatively. The technical success rates of the diagnostic or therapeutic intervention were not significantly different between the 2 groups in patients undergoing successful direct POC. CONCLUSIONS: Free-hand biliary insertion of the MB ultra-slim endoscope showed a high technical success rate without severe adverse events and effectively decreased procedure time compared with a conventional ultra-slim endoscope. Direct POC using the MB ultra-slim endoscope can be used for novel diagnostic and therapeutic procedures of the biliary tree without the assistance of another endoscope or accessory. (Clinical trial registration number: NCT02189421.).

Prospective multicenter international study on the outcomes of a newly developed self-approximating lumen-apposing metallic stent for drainage of pancreatic fluid collections and endoscopic necrosectomy.

BACKGROUND: A novel self-approximating lumen-apposing metallic stent (LAMS; Niti-S Spaxus, Taewoong Medical, Gyeonggi-do, Korea) has recently become available. The aim of the present study was to evaluate the outcomes for drainage of pancreatic fluid collections (PFC). METHODS: This was a prospective international multicentered study conducted in six high-volume institutions across Asia. Consecutive patients suffering from pancreatic pseudocyst or walled-off pancreatic necrosis (WOPN) requiring endoscopic ultrasonography-guided drainage were recruited. Outcomes included technical and clinical success, adverse events, procedural events, interventions through the stent and recurrence rates. RESULTS: Between August 2016 and November 2017, 59 patients were recruited to this study. Thirty-nine patients (66.1%) had WOPN and mean (SD) size of PFC was 11.5 (5.1) cm. Technical and clinical success rates were 100%. Mean (SD) procedural time was 35.0 (17.2) minutes. Sixteen-millimeter stents were used in 66.1% of the patients. Fifty-four sessions of necrosectomy were carried out with the stent in situ in 17 patients. Stent-related adverse event (AE) rate was 6.8%. Three patients (5.1%) suffered from bleeding after stenting and one required angiographic embolization. Two patients (3.4%) suffered from recurrence during a mean (SD) follow-up time of 325.6 (355.5) days. There were no differences in outcomes between those with pseudocysts or WOPN except for the duration of hospital stay (P = 0.012). CONCLUSION: Use of a self-approximating LAMS for drainage of PFC was safe and effective. Endoscopic necrosectomy could be carried out through the stent with ease. The device was associated with a low rate of stent-related AE.

Efficacy of a novel lumen-apposing metal stent for the treatment of symptomatic pancreatic pseudocysts (with video).

BACKGROUND AND AIMS: Recently, a newly designed lumen-apposing metal stent (LAMS) with a conventional delivery system was developed. The purpose of this study was to evaluate the effectiveness and safety of a newly designed LAMS for EUS-guided drainage to treat symptomatic pancreatic pseudocysts. METHODS: This prospective multicenter cohort study included 34 patients with symptomatic pancreatic pseudocysts from 2016 to 2017. The patients underwent EUS-guided drainage with the newly designed LAMS (Niti-S SPAXUS; Taewoong Medical Co, Ltd, Ilsan, South Korea). Effectiveness outcome measurements included technical success rate, clinical success rate, successful stent removal rate, and procedural time. Safety outcome measurements included procedure and/or stent-related adverse events (AEs) and overall AEs. Patients were prospectively followed, and consecutive data were collected at discharge, at stent removal, and 20 days after stent removal. RESULTS: Thirty-four patients (mean age 51.7 ± 13.3 years, 26 men) were enrolled. The mean pseudocyst size was 9.23 ± 3.54 cm. The technical success rate was 97.1% (33/34). The clinical success rate was 94.1% (32/34). All stents were successfully removed. The mean procedural time from needle puncture to stent deployment was 10.3 ± 5.7 minutes. Four patients (11.8%) experienced procedure and/or stent-related AEs, including stent maldeployment (n = 1) and pseudocyst infection (n = 3). All patients completely recovered from the AEs. Bleeding caused by the stent or buried LAMS syndrome was not observed. No unplanned endoscopic procedures were required. CONCLUSIONS: This study showed that EUS-guided drainage using the newly designed LAMS is technically feasible and effective for the treatment of symptomatic pancreatic pseudocysts. (Clinical trial registration number: NCT02730663.).

The safety of newly developed automatic temperature-controlled endobiliary radiofrequency ablation system for malignant biliary strictures: A prospective multicenter study.

BACKGROUND AND AIMS: Catheter-based endobiliary radiofrequency ablation (RFA) is an endoscopic local treatment for patients with malignant biliary stricture (MBS). However, excessive heating of the bile duct by the current RFA system can induce serious complications. Recently, a new RFA system with automatic temperature control was developed. In the present study, we examined the safety of the new RFA system in patients undergoing endobiliary RFA for extrahepatic MBS. METHODS: This prospective, multicenter study enrolled patients with unresectable or inoperable extrahepatic (> 2 cm from the hilum) MBS. Endobiliary RFA was performed using a newly developed RFA catheter (ELRA™, STARmed, Goyang, Korea) at a setting of 7 or 10 W for 120 s and with a target temperature of 80°C. A self-expandable metallic stent was inserted after endobiliary RFA. The rate of procedure-related adverse events was assessed. RESULTS: The 30 patients were enrolled in this study. Cholangiocarcinoma was diagnosed in 19 patients, pancreatic cancer was found in 9, and gallbladder cancers were recorded in 2. The mean stricture length was 22.1 ± 6.6 mm. Post-procedural adverse events occurred in three patients (10.0%; 2 mild pancreatitis and 1 cholangitis) without hemobilia and bile duct perforation. The pancreatitis and cholangitis resolved with conservative treatment. The cumulative duration of stent patency and survival were 236 and 383 days, respectively. CONCLUSIONS: Automatic temperature-controlled endobiliary RFA using a newly developed catheter was safely applied in patents with extrahepatic MBS. Further prospective studies are needed to confirm the efficacy of endobiliary RFA for MBS.

Tissue acquisition for diagnosis of biliary strictures using peroral cholangioscopy or endoscopic ultrasound-guided fine-needle aspiration.

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.

Efficacy of 3 fine-needle biopsy techniques for suspected pancreatic malignancies in the absence of an on-site cytopathologist.

BACKGROUND AND AIMS: EUS-guided fine-needle aspiration/biopsy (EUS-FNA/B) has a high diagnostic accuracy for pancreatic tumors. Most reports have focused on the diagnostic yield of cytology or histology; the ability of various FNA/B techniques to obtain an adequate mass of cells or tissue has rarely been investigated. METHODS: Patients with suspected pancreatic malignancy underwent EUS-FNB using a 22-gauge ProCore needle by either the stylet slow-pull-back technique (group A), conventional negative suction after stylet removal (group B), or non-suction after stylet removal (group C) in the absence of an on-site cytopathologist. The adequacy of the 3 techniques based on the diagnostic yield, cellularity, blood contamination, and core-tissue acquisition was evaluated. RESULTS: A total of 50 patients (27 males) were analyzed. The mean tumor size was 21 to 40 mm in 54%. The rate of a good or excellent proportion of cellularity was highest in group A compared with groups B and C (72% vs 60% vs 50%, P = .049). A >25% rate of blood contamination was more prevalent in group B (30% vs 42% vs 10%, P = .009). The rate of adequate core-tissue acquisition was not different (52% vs 34% vs 50%, P = .140). Based on the multivariate generalized estimation equation, the stylet slow-pull-back technique and a tumor size >40 mm were favorable factors for diagnostic adequacy. CONCLUSIONS: The stylet slow-pull-back technique might enable acquisition of tissue and assessment of cellularity for the diagnosis of pancreatic tumors suspected to be malignant. (Clinical trial registration number: KCT0002190.).

Prospective Comparison of Intraductal Ultrasonography-Guided Transpapillary Biopsy and Conventional Biopsy on Fluoroscopy in Suspected Malignant Biliary Strictures.

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.

Risk factors associated with adverse events during endoscopic ultrasound-guided tissue sampling.

BACKGROUND AND AIM: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is commonly used to obtain tissue external to the gastrointestinal tract. EUS-FNA is relatively safe, but occasionally adverse events have been reported. There is scarcity of data on risk factors of adverse events. The aim of this study is to identify risk factors associated with EUS-FNA. METHODS: In this multicenter case-control study, we retrospectively reviewed 4,097 cases between 2009 and 2012 at 15 hospitals in Korea. Among the patients there were 104 cases (2.5%) who had adverse events of which 12 (0.29%) were severe. We matched 520 controls (1:5 ratios) stratified by hospital to analyze the potential risk factors. RESULTS: The most common adverse events were pancreatitis (45/104, 43.3%) and infection (46/104, 44.2%). Endoscopic retrograde cholangiopancreatography (ERCP) on the same day was a risk factor of all adverse events [OR = 2.41, 95% CI (1.41, 4.12)], pancreatitis [OR = 2.31, 95% CI (1.02, 5.25)], and infection [OR = 2.75, 95% CI (1.31, 5.78)]. More than 15 to-and-fro movements during puncture increased the risk of pancreatitis [OR = 2.30, 95% CI (1.11, 4.77)] and infection [OR = 3.65, 95% CI (1.55, 8.59)]. A higher number of punctures was positively correlated with pancreatitis [OR = 1.34, 95% CI (1.08, 1.67)] but negatively correlated with infection [OR = 0.66, 95% CI (0.48, 0.89)]. CONCLUSIONS: EUS-FNA is a safe procedure in which serious adverse events are rare. We define some risk factors of adverse events during EUS-FNA, including ERCP on the same day, a higher number of punctures, and more than 15 to-and-fro movements.

Direct peroral cholangioscopy for diagnosis of bile duct lesions using an I-SCAN ultraslim endoscope: a pilot study.

Background and study aims I-SCAN is a computed virtual chromoendoscopy (CVC) system designed to enhance surface and vascular patterns. In this study, we evaluated the usefulness of direct peroral cholangioscopy (POC) using I-SCAN compared with a conventional white-light image (WLI) to diagnose bile duct lesions. Patients and methods Patients with mucosal lesions in the bile duct detected during direct POC were enrolled prospectively. The quality of endoscopic visualization and the visual diagnosis were assessed using I-SCAN and WLI modes, respectively, during direct POC. Results A total of 20 patients (9 malignant and 11 benign lesions) underwent I-SCAN to evaluate lesions in the bile duct using direct POC. The quality of endoscopic visualization using direct POC with I-SCAN was significantly higher than that of WLI for surface structure (P = 0.04), surface microvascular architecture (P = 0.01), and margins (P = 0.02). Overall diagnostic accuracy of the visual diagnosis was not different between I-SCAN and WLI (90.0 % vs. 75.0 %; P = 0.20). Conclusion Direct POC using CVC by I-SCAN seems to be helpful for evaluating mucosal lesions of the bile duct, without the interference from bile. CLINICAL TRIAL REGISTRATION: UMIN000021009.

Bilateral versus unilateral placement of metal stents for inoperable high-grade malignant hilar biliary strictures: a multicenter, prospective, randomized study (with video).

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 < .01). In a multivariate Cox proportional hazard model to assess stent patency, bilateral SEMS placement was a favorable factor (adjusted hazard ratio 0.30, 95% confidence interval, 0.172-0.521; P < .001). Survival probability and late adverse events were not different between the 2 groups. 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.).

Diagnostic approach using ERCP-guided transpapillary forceps biopsy or EUS-guided fine-needle aspiration biopsy according to the nature of stricture segment for patients with suspected malignant biliary stricture.

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).

Partially Covered Metal Stents May Not Prolong Stent Patency Compared to Uncovered Stents in Unresectable Malignant Distal Biliary Obstruction.

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.

The Role of Endoscopic Biliary Drainage without Sphincterotomy in Gallstone Patients with Cholangitis and Suspected Common Bile Duct Stones Not Detected by Cholangiogram or Intraductal Ultrasonography.

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.

Wire-guided intraduodenal ultrasonography using a catheter probe in the differential diagnosis of enlarged ampullary lesions.

BACKGROUND AND AIM: It can be difficult to identify the cause of an enlarged ampulla of Vater (AOV). This study evaluated the accuracy of wire-guided intraduodenal ultrasonography (US) for the differential diagnosis of an enlarged AOV during endoscopic retrograde cholangiopancreatography (ERCP). PATIENTS AND METHODS: Thirty-four patients with enlarged AOVs of unknown cause identified on imaging studies or endoscopic observations underwent wire-guided intraduodenal US using a catheter probe. RESULTS: The final diagnoses were malignant or premalignant tumors in 10 patients (29.4%), stones in nine patients (26.5%), inflammation in 14 patients (41.2%), and cyst in one patient (2.9%). The overall diagnostic accuracy of intraduodenal US for enlarged AOVs was 91.2%. The diagnostic accuracies of stones, inflammation, and AOV tumors were 100.0%, 94.1%, and 91.1%, respectively. CONCLUSIONS: Wire-guided intraduodenal US using a catheter probe is readily applicable during ERCP and may be useful in the differential diagnosis of enlarged ampullary lesions.

KRAS mutation analysis by next-generation sequencing in endoscopic ultrasound-guided sampling for solid liver masses.

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.

Vascular enhancement pattern of mass in computed tomography may predict chemo-responsiveness in advanced pancreatic cancer.

INTRODUCTION: Chemo-responsiveness in pancreatic cancer is known to be dependent on fibrosis and vascularity. The purpose of this study was to assess vascular enhancement in advanced pancreatic adenocarcinoma with or without liver metastasis in computed tomography (CT) and to analyze the correlation between enhancement patterns and chemo-responsiveness. METHODS: Patients were assigned to either a responder group (partial response or stable disease) or a non-responder group (progressive disease) according to chemo-responsiveness assessed by CT before and after gemcitabine-based chemotherapy. Hounsefield unit (HU) was measured in pancreatic mass and the largest metastatic liver mass using region of interest (ROI). HU differences (ΔHU) between arterial and pre-contrast phase were calculated. RESULTS: Of the 101 study subjects, 78(77.2%) were assigned to the pancreas responder group {mean ΔHU (±SD), 36.7(±21.6)} and 23(22.8%) to the pancreas non-responder group {mean ΔHU (±SD), 20.6(±9.9)} (p = 0.001 for ΔHUs). Of the 46 study subjects with liver metastasis, 25(54.3%) were assigned to the liver metastasis responder group {mean ΔHU (±SD), 36.9(±21.0} and 21(45.7%) to the liver metastasis non-responder group {mean ΔHU (±SD), 17.1 (±24.0)}, (p = 0.005 for ΔHUs). CONCLUSION: CT determined mass vascular enhancement patterns may predict chemoresponse in advanced pancreatic cancer.

Third metal stent for revision of malignant hilar biliary strictures.

Background and study aim: Endoscopic stent-in-stent (SIS) placement of multiple metal stents is technically demanding. In the present study, we explored the technical feasibility and efficacy of endoscopic deployment of a third metal stent to create a triple SIS placement in patients with a bilateral SIS configuration for inoperable high grade malignant hilar biliary stricture (HBS) that had failed clinically. Methods: Eighteen patients with histologically proven inoperable HBS underwent deployment of an additional third metal stent as a revisionary method after early clinical failure following technically successful bilateral SIS placement using cross-wired metal stents. The main outcome measures were the technical and clinical success rates, and adverse events. Results: The overall technical and clinical success rates were 88.9 % (16/18) and 87.5 % (14/16), respectively. The early and late complications were cholangitis (n = 2) and cholecystitis (n = 1). Stent occlusion developed in 35.7 % (5/14) of patients in whom a third metal stent for revision of a bilateral SIS configuration was clinically successful. The median (range) times for stent patency and patient survival were 176 days (49 - 372) and 216 days (52 - 384), respectively. Conclusions: Endoscopic deployment of an additional third metal stent into a bilateral SIS configuration was technically feasible and effective in patients with inoperable high grade malignant HBS in whom bilateral SIS placement had failed clinically.

EUS-guided FNA and FNB after on-site cytological evaluation in gastric subepithelial tumors.

OBJECTIVE: Acquiring adequate tissue for immunohistochemical (IHC) analysis is important in the differential diagnosis of subepithelial tumors (SETs). In this study, we aimed to compare the diagnostic yield based on IHC analysis between endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and EUS-guided fine needle biopsy (EUS-FNB) after on-site cytological evaluation for cellularity in gastric SETs. METHODS: In 22 patients with gastric SETs, EUS-guided tissue sampling was performed on the same SET in a randomized sequence, with EUS-FNA followed by EUS-FNB, or vice versa. After on-site cytological evaluation for cellularity, the cytological and histological examinations were performed. RESULTS: There was a significant difference in the median number of needle passes to obtain adequate cellularity in the on-site cytological evaluation (2.0 for EUS-FNA vs 1.0 for EUS-FNB, P = 0.008). The proportion of adequate cellularity on the first needle pass was significantly higher in the EUS-FNB than in the EUS-FNA group (68.2% vs 31.8%, P = 0.034). However, diagnosis based on IHC examination was established in 15 (68.2%) and 18 (81.8%) cases by EUS-FNA and EUS-FNB, respectively (P = 0.488). CONCLUSIONS: EUS-FNB decreases the number of needle passes to obtain adequate cellularity and yields a higher proportion of adequate cellularity during the first needle pass compared with EUS-FNA in gastric SETs. However, there was no significant difference in diagnostic yield with IHC stain between the two procedures after on-site cytological evaluation for adequate cellularity.

Evaluation of a newly modified nonflared fully covered metal stent, 12 mm in diameter, for intraductal placement in patients with malignant biliary strictures: a feasibility study.

BACKGROUND AND STUDY AIM: The nonflared ends of fully covered, self-expandable, metal stents (FCSEMSs) may minimize stent-induced ductal injury. Suprapapillary intraductal placement of nonflared FCSEMSs for malignant biliary stricture might reduce duodenobiliary reflux and pancreatitis. The aim of this study was to evaluate the efficacy of a newly modified, nonflared FCSEMS for intraductal placement in patients with malignant biliary stricture. PATIENTS AND METHODS: A total of 51 patients with nonhilar, extrahepatic, malignant biliary stricture were enrolled prospectively. The nonflared FCSEMS is 12 mm in diameter, and has a central saddle and a distal lasso of 7 cm in length. An FCSEMS was placed above the papilla in all patients, with the central saddle positioned at the stricture to prevent stent migration. RESULTS: The technical and clinical success rates were 100 % and 98 %, respectively. Early adverse events occurred in one patient (2.0 %; mild pancreatitis). A total of 12 patients underwent surgery with curative intent, one of whom (8.3 %) experienced a postoperative adverse event. No stent migration occurred in any of the patients. Cholecystitis developed in one patient (2.0 %) as a late adverse event. Stent occlusion occurred in 44.7 % (17/38), and endoscopic removal of the stent was successful in 87.5 % of patients. The mean stent patency was 297 days (95 % confidence interval, 211 - 383). CONCLUSIONS: Intraductal placement of the nonflared FCSEMS, 12 mm in diameter, was feasible for the palliative and preoperative management of patients with malignant biliary stricture. Long-term follow-up and prospective comparative studies are needed to evaluate the usefulness of intraductal placement of this stent.

A newly modified access balloon catheter for direct peroral cholangioscopy by using an ultraslim upper endoscope (with videos).

BACKGROUND AND AIMS: Direct peroral cholangioscopy (POC) by using an ultraslim upper endoscope has been increasingly applied for diagnosis and treatment of diverse biliary diseases. Recently, an intraductal balloon catheter has been used commonly to guide the flexible ultraslim endoscope. However, accessibility into the bile duct remains a limitation of the procedure. The aim of this study was to evaluate the feasibility and success rate of an intraductal balloon-guided direct POC by using an ultraslim endoscope with a newly modified 5F balloon catheter. METHODS: In total, 36 patients with biliary obstruction were included prospectively for a direct POC by using an ultraslim endoscope with a newly modified intraductal 5F balloon catheter. The main outcome measure was technical success, defined as successful advancement of the ultraslim endoscope into the obstructed segment of the biliary tree or the bifurcation. Secondary outcomes were mean time for the total procedure, intubation into the common bile duct and advancement up to the target site after intubation of the ultraslim endoscope, technical success rates of diagnostic and therapeutic interventions, and adverse events. RESULTS: The intraductal balloon-guided direct POC using a newly modified 5F balloon catheter was completed successfully in 35 of 36 patients (97.2%). The mean times for total procedure, intubation into the distal common bile duct, and advancement up to the obstructed bile duct segment were 27.3 ± 7.2, 2.2 ± 0.5, and 0.8 ± 0.4 minutes, respectively. In total, 49 interventions were performed in 35 patients, excluding 1 patient in whom we failed to perform direct POC. Technical success of the interventions was achieved with 44 of 49 procedures (89.8%). No adverse events, including cholangitis, were observed. CONCLUSIONS: A newly modified 5F balloon catheter seemed to facilitate performing intraductal balloon-guided direct POC for direct visual examination of the bile duct in patients with biliary obstruction. Continued development of endoscopes and accessories are expected to further improve the performance of direct POC.