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Background and Aims Gene therapy could provide curative therapies to many inherited monogenic liver diseases. Clinical trials have largely focused on adeno-associated viruses (AAVs) for liver gene delivery. These vectors, however, are limited by small packaging size, capsid immune responses, and inability to redose. As an alternative, nonviral, hydrodynamic injection through vascular routes can successfully deliver plasmid DNA (pDNA) into mouse liver but has achieved limited success in large animal models. Methods We explored hydrodynamic delivery of pDNA through the biliary system into the liver of pigs using ERCP and a power injector to supply hydrodynamic force. Human factor IX (hFIX), deficient in hemophilia B, was used as a model gene therapy. Results Biliary hydrodynamic injection was well tolerated without significant changes in vital signs, liver enzymes, hematology, or histology. No off-target pDNA delivery to other organs was detected by polymerase chain reaction. Immunohistochemistry revealed that 50.19% of the liver stained positive for hFIX after hydrodynamic injection at 5.5 mg pDNA, with every hepatic lobule in all liver lobes demonstrating hFIX expression. hFIX-positive hepatocytes were concentrated around the central vein, radiating outward across all 3 metabolic zones. Biliary hydrodynamic injection in pigs resulted in significantly higher transfection efficiency than mouse vascular hydrodynamic injection at matched pDNA per liver weight dose (32.7%-51.9% vs 18.9%, P Conclusions Biliary hydrodynamic injection using ERCP can achieve higher transfection efficiency into hepatocytes compared with AAVs at magnitudes of less cost in a clinically relevant human-sized large animal. This technology may serve as a platform for gene therapy of human liver diseases.

Background and Aims Fluorescence in situ hybridization (FISH) has improved the diagnostic performance of cytology for the evaluation of malignant biliary strictures in the United States and Europe. The utility of FISH for the diagnosis of biliary strictures in Asia is currently unknown. We aimed to compare the sensitivity of FISH and conventional cytology for the diagnosis of malignant biliary strictures in Thai patients. Methods A prospective study was performed at 2 university hospitals between 2010 and 2013. Patients being evaluated for malignant-appearing biliary strictures were included (N = 99). Bile duct brushings were collected and assessed by cytology and FISH. Sensitivities with 95% confidence intervals of cytology and FISH were the main outcome measures. Results The overall sensitivities of cytology and FISH were 38% and 55%, respectively ( P = .001). For those with a diagnosis of cancer based on clinical evidence without biopsy confirmation (n = 44), the sensitivities of cytology and FISH were 43% and 57%, respectively ( P = .06). For the 49 patients for whom a cancer diagnosis was confirmed by pathology, FISH had a significantly higher sensitivity than cytology, with a sensitivity of 53% versus 33%, respectively ( P = .008). Conclusions FISH improves the diagnostic performance of cytology and can be used as a complementary tool to bile duct brushing and biopsy for the evaluation of malignancy in biliary strictures in Asian populations.

PMID = 30784507

Background Biliary tract malignancies can be assessed with either EUS or SpyGlass cholangioscopy (SGC). Objective To evaluate the impact of EUS and guided biopsy before considering SGC in patients who had biliary strictures with negative ductal brushing. Design Prospective, observational study. Setting Tertiary level referral hospital. Patients Forty consecutive patients with biliary strictures. Intervention EUS evaluation and biopsy, where possible, were performed in all patients. If EUS examination failed to provide a definitive diagnosis, SGC and ductal biopsy was performed. Results were compared with surgical specimens or positive histocytology. Main Outcome Measurements Tissue diagnosis, technical success, adverse events, and clinical outcomes. Results On EUS, abnormalities responsible for the biliary strictures were identified in 39 patients (98%), with FNA achievable in 30 patients (75%). EUS-FNA provided positive histocytology in 23 patients (58%). SGC-guided biopsy was performed to evaluate nondiagnostic EUS-FNA (17 patients) and to clarify autoimmune pancreatitis on FNA (2 patients). The procedure was successful in 18 patients (95%) and provided tissue diagnosis in 16 patients (88%), with 2 false-negative results from extrinsic pathologies. When EUS was used before the SGC approach, the need for SGC was avoided in 24 patients (60%), cholangitis was minimized in 2.5%, and a cost saving of U.S.$110,000 was realized. Tissue diagnosis was achieved in 38 patients (94%) with this approach. Limitations Relatively small sample size. Conclusions EUS evaluation in patients with difficult biliary stricture prevents the need, cost, and adverse events of SGC in 60% of patients. Together, EUS followed by the SGC approach provides correct clinical diagnosis in 94% of patients with minimal adverse events.

Background and Aims Direct per-oral cholangioscopy allows endoscopic visualization of the biliary tract. Insufflation with carbon dioxide (CO 2 ) is an alternative to saline solution irrigation during direct cholangioscopy. There are no data on maximal CO 2 insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism. We aimed to evaluate the safety of increasing CO 2 insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism. Methods This was an in vivo animal study. Four domestic pigs, under general endotracheal anesthesia, were used. The first animal was used to validate the feasibility of direct cholangioscopy and biliary pressure measurements, after which all animals underwent laparotomy, insertion of a pressure transducer in the cystic duct, and direct transpapillary placement of the cholangioscope. The common bile duct (CBD) and cystic duct were ligated to contain the instilled gas and exclusively expose the biliary tree. Insufflation of CO 2 started at 200 mL/min and was continuously increased until there was evidence of bile duct rupture (as measured by a drop in intraductal pressures) or instability of vital signs (hypotension, bradycardia, bradypnea, O 2 desaturation). Necropsy was performed on all animals to assess the liver and biliary system for evidence of barotrauma. Results CO 2 was insufflated up to 8 L/min without causing bile duct rupture or instability in vital signs despite increasing CBD pressure with insufflation. There was significant correlation between CO 2 flow with partial pressure of CO 2 in arterial blood (PaCO 2 ) (coefficient, 0.96-1.00; P 2 (EtCO 2 ) (coefficient, 0.94-1.00; P 2 did not correlate with the amount of CO 2 flow. There was no evidence of hepatic or biliary barotrauma on necropsy. Conclusions This pilot experience in porcine models suggests that CO 2 insufflation is safe for direct cholangioscopy and does not result in biliary barotrauma or vital signs instability.

Background Complications of the biliary tract after liver transplantation are successfully managed with ERCP; however, the incidence and risk factors for post-ERCP complications remain unknown. Objective To examine the incidence, risk factors, and short-term outcome of post-ERCP complications in liver transplant (LT) recipients. Design Retrospective evaluation of all ERCPs performed in LT recipients at our institution during a 7-year, 4-month period. Setting Tertiary referral center. Patients A total of 243 ERCPs performed in 121 LT recipients with duct-to-duct anastomosis. Main Outcome Measurements Incidence of post-ERCP complications. Predictive factors were determined by univariate and multivariate analyses. Results Overall complications occurred in 22 procedures (9%) (13 mild, 9 moderate): pancreatitis in 9 patients (3.7%), cholangitis in 8 patients (3.3%), postsphincterotomy bleeding in 4 patients (1.6%), and subcapsular hematoma in 1 patient (0.4%). The mean hospitalization for post-ERCP complications was 4.8 days (range 2-11 days). Logistic regression identified mammalian target of rapamycin inhibitors (odds ratio [OR], 4.65; 95% CI, 1.01-21.81; P = .049), serum creatinine level greater than 2 mg/dL (OR, 4.17; 95% CI, 1.07-16.26; P = .04), biliary sphincterotomy (OR, 3.03; 95% CI, 1.07-8.53; P = .037), and more than 2 pancreatic duct contrast injections (OR, 2.95; 95% CI, 1.10-7.91; P = .032) as independent risk factors for post-ERCP complications, whereas steroid therapy (OR, 0.23; 95% CI, 0.08-0.63; P = .004) was an independent protective factor. Limitations Single-center retrospective study. Conclusions The rate of complications after ERCP in LT recipients seems to be similar to that of non-LT recipients. Complications in this analysis were more common in LT recipients receiving mammalian target of rapamycin inhibitors and those with renal failure, biliary sphincterotomy, and more than 2 pancreatic duct injections, whereas they were less common in those patients on steroid therapy.

Background Temporary biliary stenting is both technically easy and feasible, and choleretic agents such as ursodeoxycholic acid (UDCA) and a terpene preparation may promote a reduction in stone size. However, there are few comparative data on the effectiveness of choleretic agents available. Objective To investigate the efficacy of multiple double-pigtail stents with or without UDCA and terpene on difficult common bile duct (CBD) stones. Design A prospective, multicenter study. Setting Four tertiary-care referral centers. Patients This study involved 51 patients. Intervention In total, 51 elderly patients with comorbidities who had difficult CBD stones refractory to conventional methods were randomized to receive either multiple 7F double-pigtail stents (group A) or stents in combination with UDCA and terpene (group B) for a period of 6 months. Main Outcome Measurements Stone size reduction, successful duct clearance, and complications. Results Complete endoscopic duct clearance was achieved in 14 patients (73.7%) in group A and 19 patients (86.4%) in group B ( P = .826). The mean size of CBD stones (transverse/longitudinal diameter, mean ± SD) was 19.12 ± 4.48 mm/20.47 ± 3.86 mm in group A and 21.30 ± 7.08 mm/22.58 ± 7.61 mm in group B. Stone size decreased significantly to 12.04 ± 3.26 mm/13.31 ± 5.12 mm and 13.67 ± 5.40 mm/14.04 ± 6.12 mm, respectively ( P .01). However, there was no statistical difference in stone size reduction between the two groups ( P = .685, P = .289). No serious complications related to the stent or endoscopic procedures were observed, except for cholangitis ( n = 1, group A) and distal stent migration ( n = 2, group B). Limitations Small number of patients in East Asia. Conclusion Temporary multiple double-pigtail biliary stenting was a safe and feasible method of treating difficult and large CBD stones in elderly patients and contributed to a reduction in stone size and successful duct clearance. However, the addition of choleretic agents did not result in a statistical difference in stone size or rate of successful duct clearance.

Background: Covered biliary metal stents have been developed to prevent tumor ingrowth. Previous comparative studies are limited and often include few patients. Objective: To compare differences in stent patency, patient survival, and complication rates between covered and uncovered nitinol stents in patients with malignant biliary obstruction. Design: Randomized, multicenter trial conducted between January 2006 and October 2008. Setting: Ten sites serving a total catchment area of approximately 2.8 million inhabitants. Patients: A total of 400 patients with unresectable distal malignant biliary obstruction. Interventions: ERCP with insertion of covered or uncovered metal stent. Follow-up conducted monthly for symptoms indicating stent obstruction. Main Outcome Measurements: Time to stent failure, survival time, and complication rate. Results: The patient survival times were 116 days (interquartile range 242 days) and 174 days (interquartile range 284 days) in the covered and uncovered stent groups, respectively (P = .320). The first quartile stent patency time was 154 days in the covered stent group and 199 days in the uncovered stent group (P = .326). There was no difference in the incidence of pancreatitis or cholecystitis between the 2 groups. Stent migration occurred in 6 patients (3%) in the covered group and in no patients in the uncovered group (P = .030). Limitations: Randomization was not blinded. Conclusions: There were no significant differences in stent patency time, patient survival time, or complication rates between covered and uncovered nitinol metal stents in the palliative treatment of malignant distal biliary obstruction. However, covered stents migrated significantly more often compared with uncovered stents, and tumor ingrowth was more frequent in uncovered stents.

Background The most common complication of uncovered biliary self-expandable metal stents (SEMSs) is tumor ingrowth. The addition of an impenetrable covering may prolong stent patency. Objective To compare stent patency between uncovered and partially covered SEMSs in malignant biliary obstruction. Design Multicenter randomized trial. Setting Four teaching hospitals. Patients Adults with inoperable distal malignant biliary obstruction. Interventions Uncovered or partially covered SEMS insertion. Main outcome measures Time to recurrent biliary obstruction, patient survival, serious adverse events, and mechanism of recurrent biliary obstruction. Results From October 2002 to May 2008, 129 patients were randomized. Recurrent biliary obstruction was observed in 11 of 61 uncovered SEMSs (18%) and 20 of 68 partially covered SEMSs (29%). The median times to recurrent biliary obstruction were 711 days and 357 days for the uncovered and partially covered SEMS groups, respectively ( P = .530). Median patient survival was 239 days for the uncovered SEMS and 227 days for the partially covered SEMS groups ( P = .997). Serious adverse events occurred in 27 (44%) and 42 (62%) patients in the uncovered and partially covered SEMS groups, respectively ( P = .046). None of the uncovered and 8 (12%) of the partially covered SEMSs migrated ( P = .0061). Limitations Intended sample size was not reached. Allocation to treatment groups was unequal. Conclusions There was no significant difference in time to recurrent biliary obstruction or patient survival between the partially covered and uncovered SEMS groups. Partially covered SEMSs were associated with more serious adverse events, particularly migration. (Clinical trial registration number: NCT01047332.)

Background Advantages of direct peroral cholangioscopy (DPOCS) by using an ultraslim endoscope include a single-operator platform, image quality equal to that of standard endoscopy, and separate water and air channels. However, DPOCS has significant limitations, including cumbersome biliary access, en-face position with the ampulla, and gastric looping of the endoscope. A newly designed anchoring balloon may overcome these challenges. Objective To report the feasibility of DPOCS with the anchoring balloon. Design Pilot study, porcine model. Setting Animal resources center. Intervention The anchoring balloon system developed by Cook Medical (Winston-Salem, NC) was used for DPOCS. Main Outcome Measurements Primary: Feasibility of biliary access maintenance and intraductal mobility. Secondary: Feasibility of intraductal therapeutic procedures. Results Four animal subjects underwent DPOCS with the anchoring balloon. Ductal access was achieved with sphincterotomy in 2 subjects and with a balloon sphincteroplasty in 2 subjects. Intraductal placement of the ultraslim endoscope was achieved in all biliary access attempts without balloon migration or deflation. Common bile duct, cystic duct, bifurcation, and main right and left duct direct visualization was achieved in all cases. Therapeutic interventions by DPOCS, including intraductal biopsy, balloon dilatation, and intraductal bilateral metal stent placement, were all completed successfully. Biliary perforation occurred in one case because of balloon overinflation and in a second case because of sphincterotomy. Limitations Prototype study in an animal model and small study size. Conclusion Our results show that the novel anchoring balloon system successfully and safely enables DPOCS for both diagnostic and therapeutic interventions. If corroborated in human trials, it could offer a new platform for biliary interventions.

Background A variety of factors have been linked to post-ERCP pancreatitis. However, the role of biliary stenting has not been well studied. Objective To evaluate the relationship between biliary stenting and post-ERCP pancreatitis. Design Prospective study of all patients undergoing ERCP with biliary stenting over a 7.5-year period. All patients had follow-up at 24 to 48 hours after the procedure and at 1 month. Setting A single-center tertiary referral academic medical center. Patients Consecutive patients undergoing ERCP over a 7.5-year period. Interventions Endoscopic therapy based on the indication for and findings of ERCP. Main Outcome Measurements The rate of post-ERCP pancreatitis. Results A total of 3499 patients underwent ERCP with bile duct stent placement of a native papilla performed in 660: 544 (83%) 10F and 116 (17%) 7F. The most common indication for stent placement was pancreaticobiliary malignancy in 250 patients (37%). The overall rate of pancreatitis for the entire cohort was 3.17%. Multivariate analysis identified 6 factors that were associated with pancreatitis: previous ERCP pancreatitis (odds ratio [OR], 2.44; 95% CI, 1.31-4.55), age (OR, 2.30; 95% CI, 1.44-3.67), history of acute pancreatitis (OR, 1.78; 95% CI, 1.12-2.88), pancreatic sphincterotomy (OR, 2.30, 95% CI, 1.43-3.70), suspected sphincter of Oddi dysfunction (OR, 3.91; 95% CI, 2.36-6.46), and bile duct stenting (OR, 1.72; 95% CI, 1.03-2.88). The rates of pancreatitis were not significantly different based on performing sphincterotomy before stent placement, stent type, stent length, stent size, or indication. Limitations Single-center study. Conclusions Bile duct stent placement is an independent predictor for pancreatitis, and pancreatitis is not related to performing sphincterotomy before stenting or to stent characteristics.

Background Palliation of patients with malignant hilar stenosis by stent insertion is fraught with risk of cholangitis because of contrast injection in the undrained segment. Objective The purpose of this study was to evaluate the results of unilateral metal stenting in type II and III malignant hilar biliary obstruction by using air as a contrast medium. Design Prospective, uncontrolled, single center pilot study. Setting Tertiary care referral center. Patients Cohort of 17 patients with malignant hilar obstruction. Intervention A single metallic stent was inserted in type II and III malignant hilar obstruction by using air as a contrast medium. Patients were evaluated weekly up to 1 month after stent placement. Main Outcome Measures Successful implantation, successful drainage, early complications, procedure-related mortality, 30-day mortality. Result Successful stent placement and drainage was achieved in 100% of the patients (17 of 17). No patient developed cholangitis or died within 30 days of the procedure. Limitations Small cohort of patients. Conclusion Air cholangiography provides a safe and effective roadmap for unilateral metallic stenting in type II and III malignant hilar biliary obstruction.

Background Percutaneous transhepatic biliary drainage (PTBD) may be the last resort for an occluded biliary metal stent when the ERCP was unsuccessful. Objective Because an EUS-guided biliary drainage has been proposed as an effective alternative for PTBD after a failed ERCP, we conducted this study to determine the feasibility and usefulness of an EUS-guided hepaticogastrostomy (EUS-HG) with a fully covered self-expandable metal stent (FCSEMS) for an occluded biliary metal stent after a failed ERCP. Design A case study. Setting A tertiary referral center. Patients and Interventions Five patients who had an occluded biliary metal stent inserted after a hilar bilateral metal stent or a combined duodenal and biliary metal stent insertion and for whom reinterventional ERCP was unsuccessful underwent an EUS-HG with an FCSEMS for alternative PTBD. Main Outcome Measurements Technical and functional success, procedural complications, reinterventional rate after EUS-HG with an FCSEMS, and short-term stent patency. Results In all 5 patients, an EUS-HG with an FCSEMS was technically successful. No procedural complications, such as bile peritonitis, cholangitis, and pneumoperitoneum, were observed. Functional success was also 100% (5/5). During the follow-up period (median 152 days, range 64-184 days), no late complications, such as stent migration and occlusion, were observed. Thus, no biliary reintervention was performed during the follow-up period. Limitations A small series of patients without a control group. Conclusions The EUS-HG with an FCSEMS may be feasible, effective, and an alternative PTBD for an occluded biliary metal stent after a failed ERCP.

Background Placement of biliary stents is effective for palliation of unresectable hilar malignant biliary obstruction. However, when bilateral self-expandable metal stents (SEMSs) are used, placement can be technically challenging. In many studies, side-by-side placement is performed, although it is unclear whether this is the most anatomical and functional approach. Objective We sought to assess the technical feasibility and effectiveness of deploying bilateral SEMSs with a stent-within-stent approach using commercially available stents with a large cell width. Design Retrospective study. Setting Tertiary care medical center. Patients Patients with malignant biliary hilar obstruction referred for endoscopic palliation of obstructive jaundice. Main Outcome Measurements Technical success, ie, successful bilateral SEMS placement across the stricture; functional success, ie, decrease in pretreatment bilirubin level; early and late complications; and stent patency. Results Bilateral biliary drainage was attempted and successfully established in 21 patients with malignant hilar obstruction (15 men, 6 women; mean age 63.7 [standard deviation 13.9] years), resulting in clinical improvement of obstructive symptoms. Median follow-up was 6.14 months (interquartile range 3.5-9.5 months). There were 1 (5%) early and 7 (33%) late stent occlusions that required endoscopic reintervention. The 30-day mortality rate was 10% (2 deaths). Limitations Retrospective study of a series of cases treated at a tertiary care center by expert endoscopists. Conclusions This simple technique was performed by using an open-cell expandable metal stent is technically feasible and easy and allows bilateral placement of SEMSs in patients with unresectable hilar malignancy.

Because the pancreatobiliary tract is not readily accessible to direct visualization by endoscopy, the tract remains a formidable challenge when it comes to differentiate benign from malignant pathologies. Thus, the evaluation of pancreatobiliary disease has relied on radiographic imaging by CT scan, magnetic resonance imaging, MRCP, ERCP, and EUS, where available, and/or intra-ductal ultrasound (IDUS). However, the information acquired by these indirect imaging techniques may only be suggestive of the underlying cause of the disease. Consequently, a diagnosis remains unclear in as many as 50% of patients, despite extensive investigations made with these techniques. To improve accuracy, a number of tissue-acquiring techniques have been used to obtain cytologic or histologic material from suspicious pancreatobiliary lesions. Brushing for cytologic examination from biliary or pancreatic strictures during ERCP is frequently performed with a diagnostic yield ranging from 30% to 57%. These relatively poor yield rates are related to inadequate cellular acquisition during a single brushing, which can be improved slightly by performing multiple brushing, endobiliary biopsy forceps, and/or endoscopic needle aspiration. The diagnostic yield remains less than 70% with a low negative predictive value, even when all 3 techniques are combined. The yield of EUS-guided fine-needle aspiration (FNA) for biliary strictures is also poor, comparable with cytology brushings. However, when associated with a pancreatic mass, the yield of EUS-guided FNA is significantly higher. Cholangiopancreatoscopy was developed to address the previously mentioned limitations by enabling direct visualization of the pancreatobiliary ducts. Unfortunately, although this has been available for more than 3 decades now, the role of this technology remains very limited. The reasons are multifactorial and include the following: (1) the need for two experienced endoscopists to operate

Background Covered self-expandable metallic stents (SEMSs) are designed to prevent tumor ingrowth and can be removed if necessary. Only limited comparative data are available on the performance of covered SEMSs after primary placement versus reintervention. Objective To assess the effectiveness and safety of covered SEMS placement either as primary treatment or reintervention in patients requiring palliation of malignant biliary obstruction. Design Retrospective clinical cohort study. Setting Tertiary referral center. Patients This study involved 104 patients with unresectable malignant biliary strictures. Intervention Covered biliary SEMS placement. Main Outcome Measurements Stent patency, technical success, and patient survival. Results Covered SEMSs were placed as primary treatment in 48 patients (46%), and reintervention was performed in 56 patients (54%). At 3, 6, and 12 months thereafter, the Kaplan-Meier estimated fractions of all patients with patent stents were 94%, 84%, and 58%, respectively. Covered SEMSs remained patent until the patient's death in 75 of 89 nonsurvivors (84%). Although patency rates 3, 6, and 12 months after primary placement (100%, 93%, and 82%, respectively) were higher than those after reintervention (90%, 78%, and 48%, respectively), the differences were not statistically significant ( P = .057). Overall, the most frequent adverse events were cholangitis (7%) and stent migration (4%). Limitations The distribution of stricture locations differed among the groups, and survival data suggested the presence of more extensive disease in the primary treatment group at baseline. Conclusion The clinical utility and safety of primary covered SEMS placement were confirmed. This study provides the most extensive evidence to date that reintervention with a covered SEMS can provide a useful palliative option.

Background The Wallstent has remained the industry standard for biliary self-expanding metal stents (SEMSs). Recently, stents of differing designs, compositions, and diameters have been developed. Objective To compare the new nitinol 6-mm and 10-mm Zilver stents with the 10-mm stainless steel Wallstent and determine the mechanism of obstruction. Design Randomized, prospective, controlled study. Setting Nine centers experienced in SEMS placement during ERCP. Patients A total of 241 patients presenting between September 2003 and December 2005 with unresectable malignant biliary strictures at least 2 cm distal to the bifurcation. Main Outcome Measurement Stent occlusions requiring reintervention and death. Results At interim analysis, a significant increase in occlusions was noted in the 6-mm Zilver group at the P = .04 level, resulting in arm closure but continued follow-up. Final study arms were 64, 88, and 89 patients receiving a 6-mm Zilver, 10-mm Zilver, and 10-mm Wallstent, respectively. Stent occlusions occurred in 25 (39.1%) of the patients in the 6-mm Zilver arm, 21 (23.9%) of the patients in the 10-mm Zilver arm, and 19 (21.4%) of the patients in the 10-mm Wallstent arm ( P = .02). The mean number of days of stent patency were 142.9, 185.8, and 186.7, respectively ( P = .057). No differences were noted in secondary endpoints, and the study was ended at the 95% censored study endpoints. Biopsy specimens of ingrowth occlusive tissue revealed that 56% were caused by benign epithelial hyperplasia. Conclusions SEMS occlusions were much more frequent with a 6-mm diameter SEMS and equivalent in the two 10-mm arms despite major differences in stent design, material, and expansion, suggesting that diameter is the critical feature. Malignant tumor ingrowth produced only a minority of the documented occlusions.

Background The conformability of uncovered self-expandable metal stents (SEMSs) plays an important role in maintaining stent patency. However, whether increased conformability can prolong the duration of SEMS patency remains to be proved. Objective The aim of this study was to examine the efficacy and complication rates of the Niti-D biliary uncovered metal stent (NDS), which is more conformable than the uncovered Wallstent. Design Nonrandomized, retrospective study. Setting Tertiary-care academic medical center. Patients From March 2005 to July 2007, 101 patients received an NDS (41 cases) or a Wallstent (60 cases) for malignant biliary obstruction. Interventions SEMS placement. Results Stent occlusion occurred in 11 patients (26.8%) with the NDS and 17 patients (28.3%) with the Wallstent. The median duration of stent patency tended to be longer for the NDS group (153 days) than for the Wallstent group (124 days); however, the difference was not statistically significant ( P = .204). The median duration of overall survival of patients was 160 days for the NDS and 148 days for the Wallstent. The subgroup analysis showed that 27 patients had hilar obstruction (NDS 13, Wallstent 14). The median duration of stent patency was 249 days for the NDS group and 76 days for the Wallstent group; this difference was statistically significant ( P = .006). The complications included pancreatitis in 3 NDS cases and 5 Wallstent cases. Limitation The absence of prospective randomized recruitment. Conclusion The results of this study showed no significant differences between the NDS and the Wallstent for the palliative endoscopic management of malignant biliary obstruction. There were no significant differences in patency, complication rates, and patient survival between the more conformable NDS and the conventional Wallstent. However, the NDS, which has good conformability, may be preferred for hilar obstruction.

Pancreatic-fluid collections may occur as a result of acute or chronic pancreatitis, surgery, trauma, or neoplasia. With the exception of cystic neoplasia, collections form as a consequence of either a disruption of the pancreatic duct, with subsequent fluid leakage, or maturation of peripancreatic necrosis. Indications for drainage of these collections consist of pain, gastric outlet obstruction, obstruction of the biliary tract, and infection. Therapeutic options include surgery, endoscopy, and/or percutaneous drainage. There are no randomized trials that compare any of these approaches. Surgery, which has been the criterion standard for decades, is associated with significant morbidity and mortality rates. Percutaneous drainage is attractive in that it appears to be the least invasive, but it does require the patient to have an external drain for an extended period of time and is associated with a significant rate of percutaneous fistulas. Since the first reports of endoscopic drainage of pancreatic-fluid collections in the early 1980s, experience was widely gained, with compelling results. This article reviews the current status and the future of endoscopic treatment of pancreatic-fluid collections.

Background Endoscopic retrograde biliary drainage (ERBD) by using a plastic stent is suggested to be as effective as endoscopic nasobiliary drainage (ENBD) for temporary biliary drainage in acute suppurative cholangitis (ASC). However, there are few studies that compared ERBD and ENBD in ASC. Objectives We compared the safety and efficacy of ERBD and ENBD for temporary biliary drainage in patients with ASC. Design A case series. Setting A tertiary-referral center. Patients and Interventions Eighty patients with ASC underwent endoscopic biliary drainage with ENBD (n = 41) and ERBD (n = 39). Main Outcome Measurement Clinical outcomes, including complications related to ERCP and complications related to the type of the indwelling catheter. Results Endoscopic biliary drainage was successfully achieved in all patients (100%). There were no significant differences in the demographic data between the 2 groups. There were no differences in the improvement of clinical and laboratory parameters between the 2 groups. Overall ERCP-related complication rates in the ENBD and ERBD groups were 31.7% and 38.5%, respectively ( P = .527). Hyperamylasemia occurred in 18 patients, 12.2% in the ENBD group (5/41) and 33.3% in the ERBD group (13/39) ( P = .024). Without endoscopic sphincterotomy (EST), there was no statistically significant difference in the incidence of hyperamylasemia between the 2 groups. However, with an EST, hyperamylasemia was more frequent in the ERBD group (12/28 [42.9%]) than in the ENBD group (3/27 [11.1%]) ( P = .008). Limitation A single-center experience. Conclusions Endoscopic biliary decompression, whether by ERBD or ENBD, is an effective treatment for patients with ASC. However, more frequent hyperamylasemia with ERBD and EST deserves further evaluation.

Background On occasion, it is impossible to perform ERCP with a traditional duodenoscope in patients who have had a Billroth II gastrectomy or hepatojejunostomy, and who now have biliary tract problems. Repeat surgery is not a suitable course of action in these patients. Therefore, finding alternative modalities to resolve these obstructions is of great importance. Objective To report successful endoscopic examination and treatment of difficult biliary obstructions by using double-balloon enteroscopy. Patients Five patients. Design Cases series. Intervention Double-balloon enteroscopy (DBE) for biliary tract examination and treatment. Results We report on 5 patients who underwent Billroth II gastrectomy or biliary tract Roux-en-Y surgery and who later had biliary tract obstruction from various causes. We were unable to perform ERCP with traditional duodenoscopy but successfully completed ERCP with DBE. DBE was originally designed to examine the small intestine. The successful biliary tract cannulation rate when using DBE is lower than with duodenoscope. We performed ERCP by using DBE a total of 5 times, with a successful biliary cannulation rate of 60%. We performed a special-method papillotomy in 2 patients. This method entailed inserting an electric sphincterotome through the percutaneous transhepatic cholangiography and drainage (PTCD) route after performing DBE intubation to the ampulla of Vater. We then successfully completed a papillotomy with an electric sphincterotome under DBE guidance. Conclusions DBE appears to be a promising alternative in the examination and treatment of biliary tract disease in patients after GI operations such as Billroth II gastrectomy and choledochojejunostomy.

Background The utility and safety of endoscopic biliary orifice balloon dilation (EBD) for bile duct stone removal (with use of large-diameter balloons) after biliary endoscopic sphincterotomy (BES) is currently not well established. Objective Our purpose was to evaluate the efficacy and complications of BES followed by ≥12 mm diameter EBD for bile duct stone removal. Design Retrospective, multicenter series. Setting Five ERCP referral centers in the United States. Patients and Interventions Patients who underwent attempted removal of bile duct stones by BES followed by EBD with ≥12 mm diameter dilating balloons were identified by searching the prospectively recorded endoscopic databases from 1999 to 2007. Clinical parameters, endoscopic data, and outcomes were collected and analyzed. Results One hundred three patients, mean age 70 ± 17 years (range 23-98 years), with 56 (54%) women, underwent 107 procedures. Eleven patients (11%) had a prior history of acute pancreatitis. Pancreatogram was performed in 15 (14%) patients. Median stone size and median balloon diameter used was 13 mm. Complete stone removal in the first session of EBD was accomplished in 102 (95%) procedures, and mechanical lithotripsy was required in 29 (27%). Six patients (5.4%) had documented procedure-related complications including one patient with severe bleeding and one with severe cystic duct perforation. No acute pancreatitis occurred. Conclusion EBD with a large-diameter balloon in conjunction with BES for bile duct stone removal is effective and relatively safe. This technique appears to be a reasonable alternative option when standard BES and basket or balloon sweep are inadequate to remove bile duct stones.

Background EUS may be used to reduce the need of diagnostic ERCP. Objective Our purpose was to investigate the benefits and safety of an EUS-guided versus an ERCP-guided approach in the management of suspected biliary obstructive diseases caused by choledocholithiasis, in whom a US study is not diagnostic. Design A randomized study. Setting A university medical unit. Patients Patients with clinical, biochemical, or radiologic suspicion of biliary obstruction. Interventions In the EUS group, therapeutic ERCP was performed at the same EUS session if a lesion was found. In the ERCP group, therapeutic treatment was carried out at the discretion of the endoscopist. Main Outcome Measurements The number of ERCPs avoided, procedure-related complications, and recurrent biliary symptoms on follow-up at 1 year. Results Thirty-three patients were randomized to EUS and 32 to ERCP. Three patients (9.4%) had failed ERCPs, whereas all EUS procedures were successful. Nine (27.3%) patients in the EUS group were found to have biliary lesions that were all treated by ERCP. In the ERCP group, 7 (22%) patients had biliary lesions detected that were treated in the same session. More patients had serious complications (bleeding, acute pancreatitis, and umbilical abscess) in the ERCP group. One patient in each group had recurrent biliary symptoms during follow-up. With EUS used as a triage tool, diagnostic ERCP and its related complications could be spared in 49 (75.4%) patients. Conclusions In patients suspected to have biliary obstructive disease, EUS is a safe and accurate test to select patients for therapeutic ERCP.

Background In view of the recent advancement in endoscopic devices for biliary endoscopic intervention, the expert endoscopist can address complex morbidity. However, endoscopic 3-branched partial stent-in-stent deployment of metallic stents (MS) in patients with malignant hilar biliary stricture is technically demanding. Objectives To evaluate the efficacy and safety of endoscopic 3-branched partial stent-in-stent deployment of MS. Design Case study. Setting Gastroenterological Center, Okayama University Hospital. Patients Nine consecutive patients (mean age 63 years, range 52-84 years, mean follow-up period 5 months) with malignant hilar biliary stricture were enrolled. They had cytologically or histologically proven unresectable biliary-tract carcinoma with hilar biliary stricture type IIIa or IV according to Bismuth's classification. Interventions Endoscopic 3-branched partial stent-in-stent deployment of MS in hilar biliary strictures by using a JOSTENT SelfX stent. Main Outcome Measurements The success rate of the procedure, stent patency time, reinterventions, and complications. Results Endoscopic 3-branched partial stent-in-stent deployment was successfully accomplished in all cases. The MS became obstructed in 3 cases (33%), mean 1.5 months, range 1.4 to 2.7 months. However, no MS obstruction occurred in the other 6 patients (67%), mean 11 months, range 4.7 to 16.4 months. In the obstructed cases, the deployment of 2 or 3 tube stents was completed successfully. One case of cholecystitis was observed as a short-term complication. Limitation The small number of cases. Conclusions Endoscopic 3-branched partial stent-in-stent deployment of a JOSTENT SelfX stent was effective in selected patients with high-grade malignant hilar biliary stricture.

Background Narrow-band imaging (NBI) makes it possible to emphasize the imaging of certain features, such as mucosal structures and mucosal microvessels in GI-tract diseases. Recently, video peroral cholangioscopy (POCS) was developed as a diagnostic modality for better visualization of bile-duct lesions; however, there is no report on POCS by using NBI. Objective To evaluate the clinical usefulness of POCS by using NBI for the diagnosis of biliary-tract diseases. Design Prospective case study. Setting This procedure was performed at Tokyo Medical University Hospital. Patients Twelve consecutive patients with biliary-tract diseases, including 7 bile-duct cancers and 5 benign biliary diseases, which revealed 6 bile-duct strictures and 6 filling defects by ERCP. Intervention All patients underwent POCS by using NBI. Main Outcome Measurement Efficacy and safety of this technique. Results Twenty-one lesions were evaluated by using POCS with conventional white light imaging and NBI. Although visualization of only 2 lesions (9.5%) was "excellent" by conventional observation, visualization of 12 lesions (57.4%) was "excellent" by NBI observation. Identification of the surface structure and vessels of the lesions by NBI observation was significantly better than with conventional observation ( P P Limitations Maneuverability and fragility of POCS. The current POCS is not equipped with magnification. Conclusions POCS by using NBI may be helpful for the observation of both fine mucosal structures and tumor vessels.

Background Access to the papilla of Vater or enteral anastomoses to the biliary tract or pancreatic duct is difficult in patients with altered anatomy. The usual approach to the papilla of Vater with a side-viewing duodenoscope, designed for passage through the stomach, pyloric channel, and proximal duodenum, is not suitable in postoperative patients with challenging anatomic rearrangements. There is therefore a need for better instrumentation to achieve access in patients with difficult anatomy. Objective To assess the potential of the new double balloon endoscope system for use in difficult postsurgical anatomic configurations. This system has now been utilized in several of these types of anatomic rearrangements with successful access to the papilla of Vater and hepatico-jejunal, choledocho-jejunal, or pancreatico-jejunal anastomoses. The technique of advancing the system and achieving cannulation is described. The accessories necessary and therapeutic potential are addressed. Interventions Diagnostic and therapeutic management of pancreatic and biliary disorders in altered anatomy. Conclusion Double balloon enteroscopy has provided a means to access the stomach, duodenum, biliary tract, and pancreatic duct after surgical procedures that have made access by the usual routes with the usual instruments not possible.