Plastic biliary stents are a cost-effective treatment for biliary obstruction. Unfortunately, they have low patency, related to intraluminal biofilm formation. Silver nanoparticles (AgNPs) have been increasingly used in biomedicine because of its antibacterial properties. This study aimed to compare biofilm formation on stents with and without silver nanoparticle coatings when in contact with different bacterial culture medium.

Different types of silver coatings were tested on plastic biliary stents. Two groups of stents were analyzed: one group with various types of silver nanoparticle coatings, and a negative control group with no coating. The stents were placed in different bacterial culture media and assessed for biofilm formation. Analysis was performed using confocal microscopy and direct colony-forming unit (CFU/cm2).

Quantitative analysis showed promising results with C16 coating, as Escherichia coli ATCC and Pseudomonas aeruginosa ATCC exhibited reduced growth in the AgNP-coated group (p < 0.05). However, when mixed samples, including clinical strains and Staphylococcus aureus, were tested, the AgNP coating did not inhibit bacterial growth.

AgNP-coated stents are effective against certain strains, such as E. coli ATCC and P. aeruginosa. Further research is needed to explore potential improvements in the coating mechanism.

A biofilm is a community of microbial cells which are enclosed in an external matrix and separated by a network of water channels attached to natural or artificial surfaces. Biofilms formed inside biliary stents consist of a mixed spectrum of bacterial communities, most of which usually originate from the intestines. The patency of biliary stents is the most important problem. Stent occlusion can threaten the health and even life of patients. The main cause of this phenomenon is bile sludge, which is an excellent environment for the multiplication and existence of microorganisms. Due to the great clinical importance of maintaining the patency of biliary stents, several methods have been developed to prevent the accumulation of sludge and the subsequent formation of biofilm; these include, among others, the use of anti-adhesive materials, coating the inner surface of stents with metal cations (silver, copper) or other antimicrobial substances, the implementation of biodegradable drug-eluting biliary stents and the development of a new stent design with an anti-reflux effect. This article presents the latest information on the formation of biofilms in biliary stents, as well as historical and future methods of prevention.

Endoscopic retrograde cholangiopancreatography (ERCP) has evolved from a diagnostic to a therapeutic tool in acute pancreatitis management, largely due to the availability of less invasive diagnostic modalities such as endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP).

This review explores the therapeutic applications of ERCP across various acute pancreatitis etiologies and its role in managing complications such as bile duct obstructions, pancreatic duct disruptions, and infected necrosis. The discussion highlights the procedure's expanding indications and its critical role in addressing complex cases.

ERCP remains central to the management of acute pancreatitis complications. As endoscopic techniques and devices continue to advance, its therapeutic scope is likely to grow. Performing ERCP for appropriate indications and optimizing its use is essential for minimizing risks and improving outcomes.

Objectives: In hepatopancreatic diseases, stenting is widely employed to manage cholangitis and obstructive jaundice. Stent materials are primarily categorized as plastic or metal. Plastic stents have notable advantages, such as reduced likelihood of peripheral bile duct obstruction, a lower cost, and the ease of replacement compared to metallic stents. However, their patency period is shorter due to narrower diameters. Plastic stents are typically composed of materials like polyurethane or polyethylene. To improve patency, new dual-layer stents combine polyurethane with polytetrafluoroethylene (PTFE). PTFE, used in the inner layer, is expected to prevent biofilm formation. This study aimed to assess the clinical efficacy of this dual-layer stent. Methods: A retrospective analysis was performed on 48 cases (Group R) using REGULUS® from November 2022 to November 2023 and 30 cases (Group IS) using inside-type plastic stents from January 2020 to November 2023 for malignant hilar and intrahepatic bile duct obstructions. Stent patency and clinical outcomes were compared between the groups. Results: There was no significant difference in the recurrent biliary obstruction (RBO) rate between the groups (p = 0.644). The time to recurrent biliary obstruction (TRBO) was 74 days in Group R and 118 days in Group IS, with no significant difference (p = 0.219). Conclusions: The dual-layer stent placed across the papilla demonstrated comparable clinical outcomes to inside-type stents. The PTFE inner layer likely reduces biofilm formation, enhancing patency. Across-the-papilla placement may facilitate reinterventions in challenging cases, broadening stent options.

Palliative therapy utilizing interventional stents, such as vascular stents, biliary stents, esophageal stents, and other stents, has been a prevalent clinical strategy for treating duct narrowing and partial blockage. However, stent restenosis after implantation usually significantly compromises therapeutic efficacy and patient safety. Clinically, vascular stent restenosis is primarily attributed to endothelial hyperplasia and coagulation, while the risk of biliary stent occlusion is heightened by bacterial adhesion and bile sludge accumulation. Similarly, granulation tissue hyperplasia leads to tracheal stent restenosis. To address these issues, surface modifications of stents are extensively adopted as effective strategies to reduce the probability of restenosis and extend their functional lifespan. Applying coatings is one of the technical routes involving a complex selection of materials, drug loading capacities, release rates, and other factors. This paper provides an extensive overview of state of the art drug-coated stents, addressing both challenges and future prospects in this domain. We aim to contribute positively to the ongoing development and potential clinical applications of drug-coated stents in interventional therapy.

Unresectable ampullary cancer (AC) is a rare disease entity. The risk factors for recurrent biliary obstruction (RBO) following endoscopic biliary stenting (EBS) for unresectable AC remain unknown. In this study we aimed to evaluate the cumulative RBO rate and to identify risk factors for RBO following palliative EBS in patients with unresectable AC.

This multicenter retrospective observational study enrolled consecutive patients with unresectable AC who had undergone palliative EBS between April 2011 and December 2021. The cumulative rate of and risk factors for RBO following palliative EBS were evaluated via multivariate analysis.

The study analysis comprised 107 patients with a median age of 84 years (interquartile range 79-88 years). Plastic stents (PSs) and self-expandable metal stents (SEMSs) were placed in 53 and 54 patients, respectively. Functional success was accomplished in 104 (97.2%) patients. Of these, RBO occurred in 62 (59.6%) patients, with obstruction and complete/partial migration occurring in 47 and 15 patients, respectively. The median time to RBO was 190 days. Multivariate analysis showed that PS was associated with a higher rate of RBO compared to SEMS (hazard ratio [HR] 2.48; P < 0.01) and that the presence of common bile duct stones/sludge immediately after EBS was an independent risk factor for RBO (HR 1.99; P = 0.04).

The use of SEMS compared to PS during EBS reduced the time to RBO in patients with unresectable AC. Common bile duct stones/sludge immediately after EBS was a risk factor for RBO.

Biliary stents are used to optimize ductal patency and enable bile flow in the management of obstruction or injury related to biliary tract tumors, strictures, stones, or leaks. Although direct therapeutic applications of biliary stents are less well developed, stents can be used to deliver drugs, radioisotopes, and photodynamic therapy.

This report provides an in-depth overview of the clinical indications, and therapeutic utility of biliary stents. Unique considerations for the design of biliary stents are described. The properties and functionalities of materials used for stents such as metal alloys, plastic polymers, or biodegradable materials are described, and opportunities for design of future stents are outlined. Current and potential applications of stents for therapeutic applications for biliary tract diseases are described.

Therapeutic biliary stents could be used to minimize inflammation, prevent stricture formation, reduce infections, or provide localized anti-cancer therapy for biliary tract cancers. Stents could be transformed into therapeutic platforms using advanced materials, 3D printing, nanotechnology, and artificial intelligence. Whilst clinical study and validation will be required for adoption, future advances in stent design and materials are expected to expand the use of therapeutic biliary stents for the treatment of biliary tract disorders.

To describe the application of uncovered balloon-expandable metallic biliary stents for treatment of extrahepatic biliary obstructions (EHBOs) and the outcomes for dogs and cats treated for EHBO with this technique.

Retrospective single institutional study.

Eight dogs and three cats treated at the Veterinary Specialty Hospital of San Diego for EHBO between January 2012 and February 2022.

Data collected from the medical records included signalment, presenting complaint, laboratory and imaging findings, surgical findings, hospitalization time, complications, and follow-up information.

Median duration of short-term follow up was 16 days (6-45 days). Improved biochemical abnormalities and resolution of clinical signs were recorded in 10/11 cases. Two dogs died within 2 weeks of surgery. One dog developed systemic inflammatory response syndrome 5 days postoperatively and was euthanized; the cause of death in the second case was unknown. Long-term follow up was available in seven cases, with a median duration of 307.5 days (62-2268 days). Bile-duct patency was maintained for at least 356-622 days (median: 446 days) in three cats and 62-2268 days (median: 650.5 days) in four dogs with long-term follow up available. One cat had recurrent obstruction with choledocholiths 446 days postoperatively. One stent was removed 614 days postoperatively due to recurrent cholangiohepatitis.

Uncovered balloon-expandable metallic biliary stents were placed successfully and relieved EHBO in all cases that survived to discharge.

Use of uncovered balloon-expandable metallic biliary stents should be considered as an alternative to temporary choledochal luminal stenting or cholecystoenterostomy to manage EHBO.

Biliary stents have been widely used to treat both malignant and benign biliary obstruction. Biliary stenting serves as a temporary measure to maintain ductal patency and promote bile drainage. Biliary decompression can help relieve clinical symptoms of pain, obstructive jaundice, pruritis, fat malabsorption, and failure to thrive and prevent disease progression, such as secondary biliary cirrhosis and end-stage liver failure. Endoscopic placement of biliary endoprosthesis is a minimally invasive procedure well tolerated by most patients but is not without problems. Multiple early and late complications have been reported in the literature and Computed Tomography (CT) is the most used modality to assess normal positions and evaluate patients suspected of stent complications. The aim of this article is to provide a review various of biliary stent related complications, as seen on CT. Current literature on risk factors, diagnosis and management is also discussed.

As of date, endoscopic biliary stenting with plastic stent (PS) and self-expandable metal stent (SEMS) have been widely used for the palliation of biliary tract strictures. However, these two stents have several limitations regarding the management of biliary strictures caused by intrahepatic and hilar cholangiocarcinoma. PS has short patency and also risks bile duct injury and bowel perforation. SEMS is difficult to revise when occluded by tumor overgrowth. To compensate for such shortcomings, we developed a novel biliary metal stent with coil-spring structure. The aim of this study was to investigate the feasibility and efficacy of the novel stent in a swine model.

The biliary stricture model was prepared in six mini-pigs using endobiliary radiofrequency ablation. Conventional PS (n=2) and novel stents (n=4) were deployed endoscopically. Technical success was defined as successful stent placement and clinical success was defined as >50% reduction of serum bilirubin level. Adverse events, stent migration, and endoscopic removability for one month after stenting were also assessed.

The biliary stricture was successfully created in all animals. The technical success rate was 100 %, and the clinical success rate was 50% in the PS group and 75% in the novel stent group. In the novel stent group, the median pre- and post-treatment serum bilirubin levels were 3.94 and 0.3 mg/dL. Stent migration occurred in two pigs and two stents were removed by endoscopy. There was no stent-related mortality.

The newly designed biliary metal stent was feasible and effective in a swine biliary stricture model. Further studies are needed to verify the usefulness of the novel stent in the management of biliary strictures.

Hepatic alveolar echinococcosis (HAE) is considered to be one of the most deadly chronic parasitic diseases in the world. We have shown that the incidence of cholangitis in patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) was increased significantly. On this finding, we carried out, a preliminary study on the risk factors for cholangitis after ERCP.

To retrospectively detect the risk factors for post-ERCP cholangitis in patients with biliary tract affected by HAE.

The study included data from 51 cases of AE who had undergone therapeutic ERCP between January 2015 and December 2019. Demographic and treatment data were extracted from the medical records, and the association between potential risk factors and the development of post-ERCP cholangitis was evaluated using a collected database.

There were five cases of mild cholangitis after ERCP (Tokyo criteria), and no moderate or severe cholangitis occurred. The incidence rate of cholangitis after ERCP was 9.8%. Univariate analysis showed hilar bile duct stenosis (p = .016), endoscopic retrograde biliary drainage (p = .007), a stent diameter ≥8.5 Fr (p = .000) and single stent implantation (p = .010) were risk factors for post -ERCP cholangitis. All cases of cholangitis improved under conservative treatment.

Patients with hilar bile duct compression or endoscopic retrograde biliary drainage appeared to be more likely to develop post-ERCP cholangitis. The number and diameter of biliary stents may influence post-ERCP cholangitis. Sample size and clinical heterogeneity are two insurmountable difficulties, and a larger sample size needs to be collected to verify the risk factors for screening. KEY MESSAGESMany studies reported the post-ERCP complications in patients with hepatic alveolar echinococcosis and found that the incidence of post-ERCP cholangitis was significantly high. Therefore, we conducted a preliminary study on the risk factors of postoperative cholangitis in patients who underwent ERCP.The incidence rate of cholangitis after ERCP was 9.8%. We found that hilar bile duct stenosis, and endoscopic retrograde biliary drainage, were risk factors for cholangitis, and stent diameter and the number of stent implantation may influence the incidence rate of cholangitis after ERCP.Sample size and clinical heterogeneity are two insurmountable difficulties, and a larger sample size needs to be collected to verify the risk factors of screening.

Endobiliary radiofrequency ablation (RFA), usually combined with endoscopic stent insertion, is a simple procedure with the potential to improve stent patency and patient survival for malignant biliary obstruction. We conducted this randomized multicenter trial to evaluate the impact of RFA on stent patency.

Eighty-six patients with malignant biliary obstruction and nonresectable tumors (pancreatic carcinoma, cholangiocarcinoma, or metastases) were included and randomly assigned to receive a self-expandable metal stent (SEMS) only (n = 44) or RFA followed by SEMS insertion (RFA+SEMS, n = 42). The primary outcome measure was stent patency after 3 and 6 months; secondary outcome measures were patient survival and early adverse events within 30 days.

Technical success rates for RFA and stent insertion were 100% and 98.8%, respectively. Stent patency after 3 and 6 months did not differ significantly between groups (RFA+SEMS group, 73.1% and 33.3%, respectively; SEMS-only group, 81.8% and 52.4%, respectively; P = .6). Similarly, the addition of RFA did not impact overall survival (hazard ratio, .72; P = .389 for RFA+SEMS). The adverse event rate in the RFA+SEMS group was 10.5% compared with 2.3% in the SEMS-only group, without a statistically significant difference (P = .18).

RFA as an addition to SEMS implantation had no positive impact on patency rate or survival. (Clinical trial registration number: DRKS00018993.).

The main limitation of plastic stents is the relatively short stent patency due to occlusion. We designed enteral extended biliary stents with lengths of 26 cm (EEBS-26 cm) and 30 cm (EEBS-30 cm) to prolong stent patency. This study aimed to compare patency among EEBS-26 cm, EEBS-30 cm, and conventional plastic biliary stent (CPBS).

A single-center prospective randomized controlled study was conducted. Eligible patients were randomized into the EEBS-26 cm, EEBS-30 cm, and CPBS groups, respectively. All patients were followed up every 3 months until stent occlusion, patient death, or at 12-month follow-up. The primary outcome was stent patency. The secondary outcomes included stent occlusion rate, patient survival, mortality, the rate of technical success, and adverse events.

Totally 117 patients were randomized into the three groups. There were no significant differences among the three groups in technical success rate, hospital stay, mortality, patient survival, and adverse events (P = 1.000, 0.553, 0.965, 0.302, and 0.427, respectively). Median stent patency durations in the EEBS-26 cm, EEBS-30 cm, and CPBS groups were 156.0 (95% CI 81.6-230.4) days, 81.0 (95% CI 67.9-94.1) days, and 68.0 (95% CI 20.0-116.0) days, respectively (P = 0.002). The EEBS-26 cm group had longer stent patency compared with the CPBS (P = 0.007) and EEBS-30 cm (P < 0.001) groups. The EEBS-26 cm group had lower stent occlusion rates compared with the other groups at 6 months (48.1% vs. 90.5% vs. 82.8%, P = 0.001) and 9 months (75.0% vs. 100.0% vs. 92.9%, P = 0.022).

EEBS-26 cm has prolonged stent patency and is safe and effective for the alleviation of unresectable extrahepatic malignant biliary obstruction.

Common bile duct stones (CBDSs) occasionally cause serious diseases, and endoscopic extraction is the standard procedure for CBDS. To prevent biliary complications, cholecystectomy is recommended for patients who present with gallbladder (GB) stones after endoscopic CBDS extraction. However, CBDS can occasionally recur. To date, the occurrence of CBDS after endoscopic CBDS extraction and subsequent cholecystectomy is not fully understood. Hence, the current study aimed to evaluate the incidence of postoperative CBDSs.

This retrospective observational study included consecutive patients who underwent postoperative endoscopic retrograde cholangiography after endoscopic CBDS extraction and subsequent cholecystectomy between April 2012 and June 2021 at our institution. After endoscopic CBDS extraction, a biliary plastic stent was inserted to prevent obstructive cholangitis. Endoscopic retrograde cholangiography was performed to evaluate postoperative CBDSs after cholecystectomy until hospital discharge. The outcomes were the incidence of postoperative CBDSs and CBDSs/sludge. Moreover, the predictive factors for postoperative CBDSs were evaluated via univariate and multivariate analyses.

Of eligible 204 patients, 52 patients (25.5%) presented with postoperative CBDSs. The incidence rate of CBDS/sludge was 36.8% (n = 75). Based on the univariate analysis, the significant predictive factors for postoperative CBDSs were ≥ 6 CBDSs, presence of cystic duct stones, and ≥ 10 GB stones (P < 0.05). Moreover, male sex and < 60-mm minor axis in GB might be predictive factors (P < 0.10). Based on the multivariate analysis, ≥ 6 CBDSs (odds ratio = 6.65, P < 0.01), presence of cystic duct stones (odds ratio = 4.39, P < 0.01), and ≥ 10 GB stones (odds ratio = 2.55, P = 0.01) were independent predictive factors for postoperative CBDSs.

The incidence of postoperative CBDS was relatively high. Hence, patients with predictive factors for postoperative CBDS must undergo imaging tests or additional endoscopic procedure after cholecystectomy.

Benign biliary strictures (BBS) can be associated with several causes, with postoperative and inflammatory strictures representing the most common ones. Endoscopy represents nowadays the first-line treatment in the management of BBS. Endoscopic balloon dilatation, plastic stents placement, fully covered metal stent placement, and magnetic compression anastomosis are the endoscopic techniques available for the treatment of BBS. The aim of this study is to perform a review of the literature to assess the role of endoscopy in the management of BBS and to evaluate the application of the different procedures in the different clinical settings.

The main disadvantage of plastic stents is the high rate of stent occlusion. The usual replacement interval of biliary plastic stents is 3 months. This study aimed to investigate if a shorter interval of 6-8 weeks impacts the median premature exchange rate (mPER) in benign and malignant biliary strictures.

All cases with endoscopic retrograde cholangiopancreatography (ERCP) and plastic stent placement were retrospectively analyzed since establishing an elective replacement interval of every 6-8 weeks at our institution and mPER was determined.

A total of 3979 ERCPs (1199 patients) were analyzed, including 1262 (31.7%) malignant and 2717 (68.3%) benign cases, respectively. The median stent patency (mSP) was 41 days (range 14-120) for scheduled stent exchanges, whereas it was 17 days (1-75) for prematurely exchanged stents. The mPER was significantly higher for malignant (28.1%, 35-50%) compared with benign strictures (15.2%, 10-28%), P < 0.0001, respectively. mSP was significantly shorter in cases with only one stent (34 days [1-87] vs 41 days [1-120]) and in cases with only a 7-Fr stent (28 days [2-79]) compared with a larger stent (34 days [1-87], P = 0.001). Correspondingly, mPER was significantly higher in cases with only one stent (23% vs 16.2%, P < 0.0001) and only a 7-Fr stent (31.3% vs 22.4%, P = 0.03).

A shorter replacement interval does not seem to lead to a clinically meaningful reduction of mPER in benign and malignant strictures. Large stents and multiple stenting should be favored as possible.

We demonstrate the potential of a novel self-expandable biliary stent comprised of poly(vinyl alcohol) (PVA) hydrogel with anisotropic swelling behavior and endoscopic deliverability in vivo, using a porcine stent model. The mechanism underlying the anisotropic swelling behavior and endoscopic deliverability (i.e., flexibility) was investigated by scanning electron microscopy (SEM), small-angle X-ray scattering (SAXS), evaluation of the water content and swelling ratio, and three-point bending tests. The in vivo experiment using a porcine stent model indicated that the tube-shaped PVA hydrogel could effectively expand the biliary tract, without disturbing bile flow. SEM and SAXS showed that PVA hydrogels prepared by drying under extension showed structural orientation along the extension axis, leading to anisotropic swelling. The water content of the PVA hydrogel was found to be crucial for maintaining flexibility as well as endoscopic deliverability. In conclusion, this study demonstrated the novel concept of using a hydrogel stent as a self-expandable biliary stent.

The clinical outcomes and prevalence of adverse events associated with biliary biodegradable stents (BS) can differ according to degradation process and time. The aim of this study was to observe the degradation process and time of different BS prototypes, and to evaluate sequential changes in their mechanical properties.

Using an in vitro bile flow phantom model, we compared degradation time, radial force changes, and morphologic changes among four different BS prototypes: polydioxanone (PDO) BS, polyglycolide (PGA) BS, polydioxanone/poly-l-lactic acid (PDO/PLLA) sheath-core BS, and polydioxaone/magnesium (PDO/Mg) sheath-core BS. Using an in vivo swine bile duct dilation model, we performed a direct peroral cholangioscopy (DPOC) examination to observe the biodegradation process and related adverse events at regular intervals.

In the bile flow phantom model, the PGA BS and PDO/Mg BS prototypes showed rapid radial force reduction and morphological changes and complete degradation within six weeks. PDO/PLLA BS maintained high radial force and kept their original shape for longer than the PDO BS, up to 16 weeks. A total of 24 BS were inserted into the dilated bile ducts of 12 swine. In this animal model, DPOC examination revealed that PDO BS and PDO/PLLA BS maintained their original shapes for approximately 12 weeks, but PDO BS showed a greater degree of fragmentation and induced biliary stones and bile duct obstruction.

Our results showed that PDO/PLLA BS maintained their original shape and radial force for a relatively long time and minimized adverse events.

Patients with advanced malignant obstructive jaundice often require biliary drainage. Resources restraint makes clinicians need to outweigh effectiveness of each biliary stents and their costs. Hence, a cost-effectiveness analysis is necessary.

A retrospective cohort study was done on malignant biliary obstruction patients undergoing palliative biliary stenting between January 2015 and December 2018. We evaluated 180-day survival rate using log-rank test and stent patency duration using Mann-Whitney U test. Effectiveness was defined as stent patency, while cost was calculated using hospital perspective using decision tree model and reported as incremental cost-effectiveness ratio.

A total of 81 men and 83 women were enrolled in this study. One hundred and eighty days survival rate was 35.9% (median 76 days, 95% confidence interval [CI] 50-102 days) and 33.3% (median 55 days, 95% CI 32-78 days), while average stent patency was 123 (8) days versus 149 (13) days for plastic and metal stent groups, respectively (P > 0.05). Metal stent could save Indonesian Rupiah (IDR) 1 217 750 to get additional 26 days of patency.

There were no differences in survival and stent patency between the two groups. Metal biliary stent is more cost-effective than plastic stent for palliation in malignant biliary obstruction.

There is little data available on the role of new anti-reflux plastic stents (ARPSs).

To compare the use of ARPSs with that of traditional plastic stents (TPSs) for patients with biliary strictures.

Consecutive patients with biliary strictures who underwent first endoscopic biliary stenting between February 2016 and May 2019 were included. The onset of stent-related cholangitis, stent patency, clinical success, and other adverse events were evaluated.

Sixty-seven patients in the ARPS group and 66 patients in the TPS group were included in the final analyses. Fewer patients experienced stent-related cholangitis in the ARPS group than that in the TPS group (8 patients vs 18 patients; P = 0.030). The median time till the onset of first stent-related cholangitis was later in the ARPS group than that in the TPS group (128.5 d vs 76 d; P = 0.039). The cumulative median stent patency in the ARPS group was 185 d, which was significantly longer than that in the TPS group (133 d; P = 0.001). The clinical success rates and other adverse events did not significantly differ between both groups.

Placement of new ARPS might be a safe and effective optional therapeutic strategy to reduce the risk of stent-related cholangitis and prolong stent patency.

The combat penetrating gunshot injury is frequently associated with damage to the liver. Bile leak and external biliary fistula (EBF) are common complications. Biliary decompression is commonly applied for the management of EBF. Also, little is known about the features of combat trauma and its management in ongoing hybrid warfare in East Ukraine. A 23-year-old male was diagnosed with thoracoabdominal penetrating gunshot wound (GSW) by a high-energy multiple metal projectile. Damage control tactics were applied at all four levels of military medical care. Biliary decompression was achieved by endoscopic retrograde cholangiopancreatography (ERCP), endoscopic sphincterotomy (EST) and the placement of biliary stents. Occlusion of the stent was treated by stent replacement, and scheduled ERCP was performed. Partial EBF was diagnosed from the main wound defect of the liver and closed without surgical interventions on the 34th day after the injury. A combination of operative and nonoperative techniques for the management of the combat GSW to the liver is effective along with the application of damage control tactics. A scheduled ERCP application is an effective approach for the management of EBF, and liver resection could be avoided. A successful biliary decompression was achieved by the transpapillary intervention with the installation of stents. Stent occlusion could be diagnosed in the early post-traumatic period, which is effectively managed by scheduled ERCP as well as stent replacement with a large diameter as close as possible to the place of bile leak.

For unresectable hilar obstruction, restoring and maintaining biliary ductal patency are crucial for improved survival and quality of life. The endoscopic placement of stents is now a mainstay of its treatment, and bilateral stenting is effective for biliary decompression. This study aimed to determine the clinical outcomes of bilateral metal stent placement using large cell-type stents and the clinical predictors of stent dysfunction in patients with malignant hilar obstruction.

We performed a retrospective analysis of patients who underwent bilateral metal stent placement using two large cell-type stents at two academic teaching hospitals between September 2017 and February 2019. The primary outcome was stent dysfunction. Secondary outcomes included predictors related to stent dysfunction and overall survival.

The study included 87 patients who underwent bilateral metal stent placement for malignant hilar obstruction. Technical success and clinical success were achieved in 80 patients (92.0%) and 83 patients (95.4%), respectively. During the follow-up period (median: 201, range: 18-671 days), stent dysfunction occurred in 42 patients (48.3%), and the median stent patency was 199 days (95% confidence interval [CI]: 181-262). In univariate analysis, age, cholangitis before stent insertion, and subsequent chemotherapy were found to be associated with the cumulative risk of stent dysfunction. In multivariate analysis, cholangitis before stent insertion (hazards ratio [HR]: 2.26, 95% CI: 1.216-4.209, P = 0.010) and subsequent chemotherapy (HR:  0.250, 95% CI: 0.130-0.482, P<0.001) remained as statically significant factors associated with the cumulative risk of stent dysfunction. The median overall survival was 288 days (95% CI: 230-327).

The bilateral placement of large cell-type stents for malignant hilar obstruction was effective with high technical and clinical success rates and acceptable patency. Cholangitis before stent insertion was associated with shorter patency, and subsequent chemotherapy was associated with longer stent patency.

Malignant biliary obstruction (MBO) is usually caused by biliary tract cancer or pancreatic cancer. This study was performed to summarize the current situation regarding palliative endoscopic retrograde biliary drainage (ERBD) for MBO in Korea and to determine its clinical significance by analyzing representative nationwide data.

Patients that underwent palliative ERBD for MBO between 2012 and 2015 were identified using the Health Insurance Review and Assessment database, which covers the entire Korean population. We assessed clinical characteristics and complications and compared the clinical impacts of initial metal and plastic stenting in these patients.

A total of 9,728 subjects (mean age, 65 ± 11.4 years; male, 61.4%) were identified and analyzed. The most common diagnosis was malignant neoplasm of liver and intrahepatic bile ducts (32.1%) and this was followed by extrahepatic or Ampulla of Vater cancer and pancreatic cancer. Initial plastic stent(s) placement was performed in 52.9% of the study subjects, and metal stent(s) placement was performed in 23.3%. The number of sessions of endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic biliary drainage (PTBD) was significantly higher in patients that underwent initial plastic stenting than in patients that underwent metal stenting (2.2 ± 1.7 vs 1.8 ± 1.4, P < 0.0001), but rates of post-ERCP pancreatitis, hospital days, and time to second ERCP or PTBD were not significantly different.

This nationwide assessment study suggests that initial metal stenting is associated with fewer sessions of total ERCP or PTBD following the initial procedure, despite the preference for initial plastic stenting in Korea.

Malignant hilar biliary obstruction (HBO) represents a complex clinical condition in terms of diagnosis, surgical and medical treatment, endoscopic approach, and palliation. The main etiology of malignant HBO is hilar cholangiocarcinoma that is considered an aggressive biliary tract's cancer and has still today a poor prognosis. Endoscopy plays a crucial role in malignant HBO from the diagnosis to the palliation. This technique allows the collection of cytological or histological samples, direct visualization of the suspect malignant tissue, and an echoendoscopic evaluation of the primary tumor and its locoregional staging. Because obstructive jaundice is the most common clinical presentation of malignant HBO, endoscopic biliary drainage, when indicated, is the preferred treatment over the percutaneous approach. Several endoscopic techniques are today available for both the diagnosis and the treatment of biliary obstruction. The choice among them can differ for each clinical scenario. In fact, a personalized endoscopic approach is mandatory in order to perform the proper procedure in the singular patient.

Endoscopic transpapillary gallbladder drainage (ETGBD) has been proposed as an alternative to surgery or percutaneous cholecystostomy in patients with acute calculus cholecystitis (ACC). We aimed to evaluate the safety and efficacy of ETGBD via endoscopic transpapillary gallbladder stenting (ETGBS) or endoscopic naso-gallbladder drainage (ENGBD) as either a bridging or a definitive treatment option for patients with ACC when a cholecystectomy is delayed or cannot be performed.

From July 2014 to December 2018, 171 patients with ACC in whom ETGBD were attempted were retrospectively reviewed. The technical and clinical success rates and adverse events were evaluated. Moreover, the predictive factors for technical success and the stent patency in the ETGBS group with high surgical risk were examined.

The technical and clinical success rates by intention-to-treat analysis for ETGBD were 90.6% (155/171) and 90.1% (154/171), respectively. Visible cystic duct on cholangiography were significant technical success predictor (adjusted odds ratio: 7.099, 95% confidence interval: 1.983-25.407, P = 0.003) as per logistic regression analysis. Adverse events occurred in 12.2% of patients (21/171: mild pancreatitis, n = 9; acute cholangitis, n = 6; post-endoscopic sphincterotomy bleeding, n = 4; and stent migration, n = 1; ACC recurrence, n = 1), but all patients were treated with conservative management and endoscopic treatment. Among the ETGBS group, the median stent patency in 70 patients with high surgical risk was 503 days (interquartile range: 404.25-775 days).

ETGBD, using either ETGBS or ENGBD, may be a suitable bridging option for ACC patients unfit for urgent cholecystectomy. In high surgical risk patients, ETGBS may be a promising and useful treatment modality with low ACC recurrence.

Pancreatic cancer is a major cause of cancer-related mortality and morbidity, and its incidence is increasing as the population is aging. On the other hand, significant improvement in the prognosis has not occurred. The absence of early diagnosis means that many patients are diagnosed only when they develop symptoms, such as jaundice, due to a biliary obstruction. The role of endoscopy in multidisciplinary care for patients with pancreatic cancer continues to evolve. Controversy remains regarding the best preoperative biliary drainage in patients with surgically resectable pancreatic head cancer. In general, patients undergoing a surgical resection usually do not require preoperative biliary drainage unless they have cholangitis or receive neoadjuvant chemotherapy. If biliary drainage is performed prior to surgery, the patient's condition and a multidisciplinary approach should be considered. With the increasing life expectancy of patients with pancreatic cancer, the need for more long-time biliary drainage or pre-operative biliary drainage is also increasing. Strong evidence of endoscopic retrograde cholangiopancreatography (ERCP) as a first-line and essential treatment for biliary decompression has been provided. On the other hand, the use of endoscopic ultrasound-guided biliary drainage as well as percutaneous biliary drainage has been also recommended. During ERCP, self-expandable metal stent could be recommended instead of a plastic stent for the purpose of long stent patency and minimizing stent-induced complications. In this review, several points of view regarding the relief of obstruction in patients with pancreatic cancer, and optimal techniques are being discussed.

To elucidate the overall risk and risk factors for developing cholangitis following biliary stent placement by endoscopic retrograde cholangiopancreatography (ERCP) and to determine the clinical outcomes of these individuals.

We performed a retrospective review of 796 patients who had undergone 1127 ERCPs with biliary stent placement between 2007 and 2015 at a single tertiary care center. There were 91 episodes of stent-associated cholangitis (SAC) during the study period. Data obtained through the medical records included ERCP indication, patient factors (biliary anatomy, demographics, and comorbidities), stent characteristics (material, length, and design), change in serum bilirubin, stent indwelling time, rates and etiologies of bacteremia, and the mortality rate.

Those with SAC were more likely to have an anatomic biliary stricture (13.1% vs. 2.3%, p < .0001), with hilar and multiple strictures having the highest risk (19.1% vs. 11.6%, p = .04). The ERCP indication of malignant biliary obstruction was associated with higher rates of SAC (15.6% vs. 3.4%, p = < .0001). Rates of SAC were higher in those who failed to normalize total bilirubin (16.9% vs. 7.8%, p = .0005), and these episodes occurred earlier compared to those who normalized total bilirubin (median 30.5 days vs. 140.5 days, p < .0001).

Patients at increased risk of SAC include those with an anatomic stricture, malignant biliary obstruction, and those who fail to normalize total bilirubin after biliary stent placement. Future protocols should be designed to reduce the risk of cholangitis in these populations.

Ureteric stents are clinically deployed to retain ureteral patency in the presence of an obstruction of the ureter lumen. Despite the fact that multiple stent designs have been researched in recent years, encrustation and biofilm-associated infections remain significant complications of ureteral stenting, potentially leading to the functional failure of the stent. It has been suggested that "inactive" side-holes of stents may act as anchoring sites for encrusting crystals, as they are associated with low wall shear stress (WSS) levels. Obstruction of side-holes due to encrustation is particularly detrimental to the function of the stent, since holes provide a path for urine to by-pass the occlusion. Therefore, there is an unmet need to develop novel stents to reduce deposition of encrusting particles at side-holes. In this study, we employed a stent-on-chip microfluidic model of the stented and occluded ureter to investigate the effect of stent architecture on WSS distribution and encrustation over its surface. Variations in the stent geometry encompassed (i) the wall thickness and (ii) the shape of side-holes. Stent thickness was varied in the range 0.3-0.7 mm, while streamlined side-holes of triangular shape were evaluated (with a vertex angle in the range 45°-120°). Reducing the thickness of the stent increased WSS and thus reduced the encrustation rate at side-holes. A further improvement in performance was achieved by using side-holes with a triangular shape; notably, a 45° vertex angle showed superior performance compared to other angles investigated, resulting in a significant increase in WSS within "inactive" side-holes. In conclusion, combining the optimal stent thickness (0.3 mm) and hole vertex angle (45°) resulted in a ∼90% reduction in encrustation rate within side-holes, compared to a standard design. If translated to a full-scale ureteric stent, this optimised architecture has the potential for significantly increasing the stent lifetime while reducing clinical complications.

Intestinal mucositis is a commonly encountered complication of chemotherapy. However, there are few effective treatments or preventive methods. Ursodeoxycholic acid (UDCA) stabilizes cell membranes, acts as an antioxidant and inhibits apoptosis, thereby exerting cytoprotective effects. The aim of the present study was to examine the ability of UDCA to protecting against chemotherapy-associated mucositis. Sprague-Dawley rats were randomly assigned to five groups: Control, vehicle + 5-fluorouracil (5-FU), 5-FU + UDCA (10 mg/kg/day), 5-FU + UDCA (100 mg/kg/day) and 5-FU + UDCA (500 mg/kg/day). Following randomization, a single dose of 5-FU was injected and varying amounts of UDCA was administered to each group. UDCA was administered orally to rats for 6 days, beginning 1 day prior to 5-FU administration. The rats were sacrificed 1 day following the last UDCA administration and intestinal tissue specimens were prepared for analysis. UDCA administration attenuated body weight loss, decreased inflammatory cytokine levels and curbed intestinal villus damage in the 10 and 100 mg/kg/day groups. When compared with the jejunal villi lengths in the vehicle+5-FU group (212.8±58.0 µm), those in the 5-FU + UDCA (10 mg/kg/day) and 5-FU + UDCA (100 mg/kg/day) groups were significantly greater [331.3±18.0 µm (P=0.001) and 310.0±112.6 µm (P=0.046), respectively]. Tumor necrosis factor-α and interleukin-6 levels were reduced in the 10 and 100 mg/kg/day UDCA groups (P<0.05). UDCA considerably attenuated the elevation in inflammatory cytokines and intestinal villus damage. The results of the study suggest that UDCA may be used as a protective agent against chemotherapy-associated intestinal mucositis.

Biofilms comprise bacterial populations enclosed in a matrix that attaches to surfaces such as medical stents. We characterized the biofilm components in occluding pancreatic stents and investigated potential factors for the formation of the biofilms.

The clinical details of 24 patients (M : F, 15 : 9) undergoing pancreatic stent retrieval were noted and the retrieved stents were processed for the quantification of biofilm proteins and polysaccharides and the molecular identification of bacteria.

The patients' ages ranged from 16 to 62 years. The underlying indications for stent insertion were bile duct stone prophylaxis against post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (n=7; 29.1 %) and pancreatic ductal leaks (n=17; 70.9 %). The retrieved stent sizes were 5 Fr (n=5; 20.8 %) and 7 Fr (n=19; 79.2 %), with a mean insertion duration of 103 days. The polybacteria detected by PCR in 95.8 % of the stents were Pseudomonas (n=8), Staphylococcus (n=8), Serratia (n=5), Aeromonas (n=4), Proteus (n=4), Klebsiella (n=4), Escherichia coli (n=4), Enterococcus (n=4), Streptococcus (n=4), Citrobacter (n=3), Bacillus (n=2), Enterobacter (n=1), Vibrio (n=1) and Clostridium (n=1). Several other organisms were identified by sequencing. The mean protein concentration was 0.585±0.29 mg ml^-1 and the mean polysaccharide concentration was 0.054±0.03 mg ml^-1. No significant differences were observed in the quantity of proteins and polysaccharides (P=0.933) for various factors, namely gender, presence of cholangitis, indications for stenting, stent sizes and duration of indwelling stents. Age was found to be a significant (P=0.013) factor for protein deposition for those aged >50 years.

The majority of the pancreatic stents grew polymicro-organisms, and those from patients aged >50 years showed significant deposition of protein, which is a key element in biofilm formation. Understanding the constituents of the biofilms in pancreatic stents could be very useful in developing future strategies for the prevention of biofilm formation.

To quantify the components in biofilms and analyze the predisposing factors involved in occlusion of biliary stents.

In a prospective study conducted from April 2011 to March 2014 at a tertiary care hospital, all consecutive patients who required endoscopic biliary stent exchange/removal were included. Etiology of the biliary disease was diagnosed by imaging, cytology and on follow-up. Clinical details of patients with biliary stent retrieval were noted. All extracted stents were collected in sterile containers and immediately processed for quantification of biofilm proteins and polysaccharides. Molecular identification of commonly known and unknown bacteria was performed by polymerase chain reaction and density gradient gel electrophoresis methods.

Eighty one patients (41 males) with age range of 20-86 years were studied. The underlying causes for stent insertion were bile duct stones (n = 46; 56.8%) benign stricture (n = 29; 35.8%) and malignancy (n = 6; 7.4%) with cholangitis in 50 (61.7%) patients. The retrieved stent sizes were 7 Fr (n = 62; 76.5%) and 10 Fr (n = 19; 23.5%) with 65 days median insertion duration. Polybacterial consortia were detected in 90.1% of the stents. The most common bacteria identified by polymerase chain reaction alone and/or sequencing were Pseudomonas (n = 38), Citrobacter (n = 23), Klebsiella (n = 22), Staphylococcus (n = 20), Serratia (n = 16), Escherichia coli (n = 14), Streptococcus (n = 13), Enterococcus (n = 13), Aeromonas (n = 12), Proteus (n = 10) and Enterobacter (n = 9). Protein concentration according to gender (0.547 ± 0.242 mg/mL vs 0.458 ± 0.259 mg/mL; P = 0.115) as well as age > 60 years and < 60 years (0.468 ± 0.295 mg/mL vs 0.386 ± 0.238 mg/mL; P = 0.205) was non-significant. However, polysaccharide concentration was significant both according to gender (0.052 ± 0.021 mg/mL vs 0.049 ± 0.016 mg/mL; P < 0.0001) and age (0.051 ± 0.026 mg/mL vs 0.038 ± 0.016 mg/mL; P < 0.011). Protein concentration in the biofilm was significantly higher (0.555 ± 0.225 mg/mL vs 0.419 ± 0.276 mg/mL; P = 0.018) in patients with cholangitis, lower (0.356 ± 0.252 mg/mL vs 0.541 ± 0.238 mg/mL; P = 0.005) in the 10 Fr group than the 7 Fr group, and significantly higher (0.609 ± 0.240 mg/mL vs 0.476 ± 0.251 mg/mL; P = 0.060) in stents of ≥ 6 mo of indwelling time. However presence/absence of cholangitis, size of stent, indication of stent insertion and indwelling time did not affect the quantity of polysaccharide concentration.

Plastic stents retrieved from patients with biliary tract disease showed polymicrobial organisms with higher protein content among patients with cholangitis and those with smaller diameter stents. Longer indwelling duration had more biofilm formation.

The geographical distribution of Greece and the growing proportion of uninsured patients make imperative the need for effective and efficient palliative solutions regarding obstructive jaundice due to hepatic malignancy, while repeated endoscopic interventions and all associated materials are either not accessible to the whole population or not even available on a daily basis due to the economic crisis and the difficulties on the hospital supply. On this basis, palliative hepatojejunostomy, introduced more than 50 years ago, could be revisited in the Greek reality in very selected cases and under these special circumstances. We report on two patients with locally advanced hilar cholangiocarcinoma and intrahepatic cholangiocarcinoma, respectively, who were treated with a combination of double hepaticojejunostomy with peripheral hepatojejunostomy or peripheral hepatoejunostomy alone, respectively. Both patients experienced an adequate decompression of the biliary tract over more than a year. Palliative hepatojejunostomy could be an ultimate solution for selected patients and circumstances in Greece during the economic crisis.

Endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is used for the management of many pancreaticobiliary disorders. It is generally safe with a few short-term complications. The risk factors for the development of post-ERCP cholangitis due to stent occlusion have not been previously described. This study identified such risk factors among patients undergoing ERCP and stent placement for pancreatic or biliary obstruction.

3648 ERCPs performed at the University of Louisville from 2008 to 2016 were reviewed. Data including patient demographics, diagnostic, laboratory, and ERCP related data were included. Patients were classified as having post-ERCP cholangitis if they developed jaundice, fever, right upper quadrant abdominal pain, and confirmatory findings of stent occlusion and/or purulent drainage at the time of repeat ERCP. These patients were compared to those who did not develop post-ERCP cholangitis using univariate and multivariate analyses.

A total of 431 patients met inclusion criteria. Of these, 57 (13.2%) developed post-ERCP cholangitis. The average age of patients was 57 years with 57% women and 43% men. On univariate analysis, patients developing post-ERCP cholangitis were more likely to be of increased age, have higher white blood cell count (WBC), total bilirubin (TBili), AST, ALT, and alkaline phosphatase (AlkPhos), and a decreased serum albumin level. Risk factors for post-ERCP cholangitis due to stent occlusion identified on multivariate analysis include: a diagnosis of cancer, the placement of multiple biliary stents at index ERCP, and low serum albumin level.

The development of post-ERCP cholangitis due to stent occlusion is strongly associated with the presence of malignancy, the placement of multiple biliary stents, and low serum albumin. A decreased threshold to monitor for stent occlusion, including routine liver function tests and prophylactic stent removal or exchange, should be employed in patients with these characteristics.

In research and development of biliary plastic stents (PS), continuous efforts have been made to overcome short patency time and high rate of migration. The aim of this study was to evaluate the patency and migration rate of different PS shapes for a given period of time.

Using an in vitro bile phantom model, we compared the patency among different shapes of PS (three straight PS, four double-pigtail PS, and a new screw-shaped PS). We performed an analysis of the degree of luminal narrowing by light microscopic examination. Using an in vivo swine model, we compared the patency and migration rate among the three different types of PS.

Eight weeks after the bile exposure in the bile flow phantom model, 80 PS were retrieved and analyzed. The straight PS showed less biofilm formation and luminal narrowing than other types of PS (p < 0.05). Forty-nine PS were inserted into the dilated bile ducts of 10 swine models, and 39 PS were successfully retrieved 8 weeks later. The stent migration occurred less frequently in the double-pigtail PS and the screw-shaped PS than it did in the straight PS (11.1, 10, and 27.3%, respectively). However, there was no statistical difference in stent patency among the different shapes.

Stent patency may not be significantly different depending on the shape of PS for 8 weeks. The screw-shaped PS showed similar patency and migration rate to the double-pigtail PS. These results may help guiding future PS development and clinical decisions.