Cost Efficacy of Metal Stents for Palliation of Extrahepatic Bile Duct Obstruction in a Randomized Controlled Trial

Association of preoperative cholangitis with outcomes and expenditures among patients undergoing pancreaticoduodenectomy

BACKGROUND

This study aimed to characterize the association of preoperative acute cholangitis (PAC) with surgical outcomes and healthcare costs.

METHODS

Patients who underwent pancreaticoduodenectomy (PD) between 2013 and 2021 were identified using 100% Medicare Standard Analytic Files. PAC was defined as the occurrence of at least 1 episode of acute cholangitis within the year preceding surgery. Multivariable regression analyses were used to compare postoperative outcomes and costs relative to PAC.

RESULTS

Among 23,455 Medicare beneficiaries who underwent PD, 2,217 patients (9.5%) had at least 1 episode of PAC. Most patients (n = 14,729 [62.8%]) underwent PD for a malignant indication. On multivariable analyses, PAC was associated with elevated odds of surgical site infection (odds ratio [OR], 1.14; 95% CI, 1.01-1.29), sepsis (OR, 1.17; 95% CI, 1.01-1.37), extended length of stay (OR, 1.13; 95% CI, 1.01-1.26), and readmission within 90 days (OR, 1.14; 95% CI, 1.04-1.26). Patients with a history of PAC before PD had a reduced likelihood of achieving a postoperative textbook outcome (OR, 0.83; 95% CI, 0.75-0.92) along with 87.8% and 18.4% higher associated preoperative and postoperative healthcare costs, respectively (all P < .001). Overall costs increased substantially among patients with more than 1 PAC episode ($59,893 [95% CI, $57,827-$61,959] for no episode vs $77,922 [95% CI, $73,854-$81,990] for 1 episode vs $101,205 [95% CI, $94,871-$107,539] for multiple episodes).

CONCLUSION

Approximately 1 in 10 patients undergoing PD experienced an antecedent PAC episode, which was associated with adverse surgical outcomes and greater healthcare expenditures.

Comparison of covered self-expandable metallic stents with 12-mm and 10-mm diameters for unresectable malignant distal biliary obstructions: a prospective randomized trial

BACKGROUND AND AIMS

Covered self-expandable metallic stents have longer patency than uncovered self-expandable metallic stents for unresectable malignant distal biliary obstruction because of the prevention of tumor ingrowth, and they are removable during reintervention. One main cause of recurrent biliary obstruction in covered self-expandable metallic stents is sludge formation, which can be prevented by using large-bore stents. We evaluated the treatment results of 12-mm and 10-mm covered self-expandable metallic stents for unresectable malignant distal biliary obstructions using a randomized controlled trial.

METHODS

This study was conducted between May 2016 and January 2019 and included 81 consecutive patients with unresectable malignant distal biliary obstruction. The primary endpoint was the rate of nonrecurrent biliary obstruction at 6 months after stent placement.

RESULTS

The primary endpoint in the 12-mm group was significantly higher than that in the 10-mm group (P = .0369). Therefore, the median time to recurrent biliary obstruction was 172 days in the 12-mm group and 120 days in the 10-mm group. The median time to recurrent biliary obstruction in the 12-mm group was significantly longer than that in the 10-mm group (P = .0168). Using the 12-mm covered self-expandable metallic stents and receiving chemotherapy were factors affecting the rate of recurrent biliary obstruction in the multivariate analysis.

CONCLUSIONS

The 12-mm covered self-expandable metallic stents provide a longer time to recurrent biliary obstruction than do 10-mm covered self-expandable metallic stents for managing unresectable malignant distal biliary obstruction. (Clinical trial registration number: UMIN000016911.).

Fully covered versus partially covered self-expandable metal stents for palliation of distal malignant biliary obstruction: a systematic review and meta-analysis

BACKGROUND AND AIMS

Self-expandable metal stents (SEMSs) are standardly used for distal malignant biliary obstruction (dMBO). Although data suggest that covered versus uncovered SEMSs increase the time to recurrent biliary obstruction (TRBO), no data are available for fully covered (FC) versus partially covered (PC) designs.

METHODS

PubMed, Scopus, and Cochrane databases were screened up to January 2023 for studies concerning dMBO treated by an FC- or PC-SEMS and describing adverse events (AEs), recurrences, or TRBO for specific design subpopulations. Pooled proportions or means were calculated using a random-effects model. Several subanalyses were preplanned, including a subanalysis restricted to prospective studies and unresectable diseases. Heterogeneity and publication bias were explored. Standardized differences (d-values) were calculated between groups.

RESULTS

From 1290 records, 62 studies (3327 using FC-SEMSs and 2322 using PC-SEMSs) were included. FC- versus PC-SEMSs showed negligible differences in the rate of total AEs (12% vs 9.9%) and all specific AEs, including cholecystitis (2.5% vs 2.6%). In a subanalysis restricted to prospective studies and unresectable diseases, the rate of RBO was comparable between FC-SEMSs (27.3% [95% confidence interval {CI}, 23.7-31.2], I2 = 35.34%) and PC-SEMSs (25.3% [95% CI, 20.2-30.7], I2 = 85.09%), despite small differences (d-values between .186 and .216) in the rate of ingrowth (.5% vs 2.9%) favoring FC-SEMSs and migration (9.8% vs 4.3%) favoring PC-SEMSs. TRBO was shorter for FC-SEMSs (238 days [95% CI, 191-286], I2 = 63.1%) versus PC-SEMSs (369 days [95% CI, 290-449], I2 = 71.9%; d-value = .116).

CONCLUSIONS

Despite considerable heterogeneity and small standardized differences, PC-SEMSs consistently exhibited longer TRBO than FC-SEMSs across analyses, without any other differences in AE rates, potentially proposing PC-SEMSs as the standard comparator and TRBO as the primary outcome for future randomized studies on dMBO. (Clinical trial registration number: CRD42023393965.).

Efficacy of multi-hole self-expandable metal stent compared to fully covered and uncovered self-expandable metal stents in patients with unresectable malignant distal biliary obstruction: a propensity analysis

BACKGROUND AND AIMS

Self-expandable metal stent (SEMS) insertion is the standard palliative treatment for unresectable malignant extrahepatic biliary obstruction (MBO). Drawbacks of conventional fully covered SEMS (FCSEMS) and uncovered SEMS (USEMS) include stent migration and tumor ingrowth, respectively. This study aimed to compare stent patency in MBO with the newly design multi-hole SEMS (MHSEMS), which has multiple small side holes in the stent membrane, with conventional FCSEMS and UCSEMS.

PATIENTS AND METHODS

This retrospective study using a propensity score matching design and stent patency times of 40 patients with MHSEMS was compared to 40 and 34 patients with FCSEMS and UCSEMS during the same period, respectively. Secondary outcomes were procedure-related adverse events, clinical success rate, time to recurrent biliary obstruction (RBO), and etiology of RBO. RBO was compared using Kaplan-Meier analysis.

RESULTS

Baseline characteristics after matching were comparable among the 3 groups. RBO rates were 21%, 37%, and 55% for MHSEMS, FCSEMS, and UCSEMS, respectively (p = 0.014), at a mean time of 479, 353, and 306 days, respectively (MHSEMS vs UCSEMS, p = 0.002). Rate of tumor ingrowth was highest in the UCSEMS group (42.4% vs 13.2% in MHSEMS; p = 0.005 and vs 0% in FCSEMS; p < 0.001). Stent migration rate was highest in the FCSEMS group at 15.8% vs 2.6% in MHSEMS (p = 0.047) and 0% in UCSEMS (p = 0.005).

CONCLUSION

MHSEMS provided the longest stent patency time with lowest RBO rate compared to conventional SEMS by showing a lower stent migration rate than FCSEMS and a lower tumor ingrowth rate than UCSEMS.

Biliary Adverse Events During Neoadjuvant Therapy for Pancreatic Cancer

OBJECTIVE

To describe a high-volume experience with biliary drainage before neoadjuvant therapy (NAT) for patients with operable pancreatic cancer (PC) and characterize the association between biliary adverse events (BAEs) and patient outcome.

BACKGROUND

Patients with PC presenting with biliary obstruction require durable decompression before NAT.

METHODS

Patients with operable PC and tumor-associated biliary obstruction were examined and grouped by the presence or absence of a BAE during NAT. The incidence, timing, and management of BAEs are described, and outcomes, including the completion of all treatment and overall survival (OS), were compared.

RESULTS

Of 426 patients who received pretreatment biliary decompression, 92 (22%) experienced at least 1 BAE during NAT, and 56 (13%) required repeat intervention on their biliary stent. The median duration of NAT was 161 days for all patients and was not different in the group that experienced BAEs. The median time from initial stent placement to BAE was 64 days. An interruption in the delivery of NAT (median 7 days) occurred in 25 (6%) of 426 patients. Among 426 patients, 290 (68%) completed all NAT, including surgery: 60 (65%) of 92 patients with BAE and 230 (69%) of 334 patients without BAE ( P =0.51). Among 290 patients who completed NAT and surgery, the median OS was 39 months, 26 months for the 60 patients with BAE, and 43 months for the 230 patients without BAE ( P =0.02).

CONCLUSIONS

During extended multimodal NAT for PC, 22% of patients experienced a BAE. Although BAEs were not associated with a significant interruption of treatment, patients who experienced a BAE had worse OS.

The role of biliary events in treatment and survival of patients with advanced pancreatic ductal adenocarcinoma

BACKGROUND

Systemic chemotherapy (CT) is the treatment of choice for advanced pancreatic ductal adenocarcinoma (PDAC). Biliary obstruction is common in this setting and may interfere with CT administration due to jaundice or cholangitis related to biliary stent malfunction.

AIMS

To evaluate the impact of biliary events on CT administration and survival in patients with stage III-IV PDAC.

METHODS

Patients enrolled in a randomized trial of nab-paclitaxel plus gemcitabine with/without capecitabine and cisplatin in advanced PDAC were included. Data on management of jaundice, biliary stents/complications and CT were prospectively collected and retrospectively analyzed. Modified overall (mOS) and progression-free (mPFS) survival were evaluated.

RESULTS

Eighty-eight patients met the inclusion criteria (50% females; median age 65years). Seven of eight (87.5%) patients who placed plastic stents developed biliary complications versus 14/30 (46.7%) with metallic stents (p = 0.071). Patients without biliary complications completed planned CT in 64.2% versus 47.6% of cases (p = 0.207). CT completion was related to longer mOS (17 vs 12 months, p = 0.005) and mPFS (9 vs 6 months, p = 0.011). mOS was shorter when biliary complications occurred (12 vs 17 months, p = 0.937), as was mPFS (6 vs 8 months, p = 0.438).

CONCLUSION

Complications related to biliary obstruction influence chemotherapy completion and survival in patients with advanced PDAC.

Best Practices in Pancreatico-biliary Stenting and EUS-guided Drainage

Indications for endoscopic placement of endoluminal and transluminal stents have greatly expanded over time. Endoscopic stent placement is now a well-established approach for the treatment of benign and malignant biliary and pancreatic diseases (ie, obstructive jaundice, intra-abdominal fluid collections, chronic pancreatitis etc.). Ongoing refinement of technical approaches and development of novel stents is increasing the applicability and success of pancreatico-biliary stenting. In this review, we discuss the important developments in the field of pancreatico-biliary stenting, with a specific focus on endoscopic retrograde cholangiopancreatography and endoscopic ultrasound-associated developments.

Short and long outcomes of endoscopic bilateral metal stent placement for malignant hilar biliary obstruction: Tertiary care oncology centre experience

INTRODUCTION

Placement of biliary self-expanding metal stents (SEMS) has been effective for palliation of unresectable hilar malignant biliary obstruction. Optimal drainage in hilar obstruction may require placement of multiple stents. Data on multiple SEMS placement in hilar obstruction from India is sparse.

METHODS

Retrospective review of patients with unresectable malignant hilar obstruction who underwent endoscopic bilateral SEMS insertion from 2017 to 2021 was done. Demographic details, technical success and functional success (decrease in the bilirubin value below 3 mg/dL at four weeks), immediate complications with 30-days mortality, requirement of re-intervention, stent patency and overall survival were studied.

RESULTS

Forty-three patients were included (mean age 54.9 years, 51.2% females). Thirty-six patients (83.7%) had carcinoma gallbladder as primary malignancy. Twenty-six patients (60.5%) were metastatic at presentation. Cholangitis was seen in 4/43 (9.3%). On cholangiogram, 26 (60.4%) had Bismuth type II block, 12 (27.8%) had type IIIA/B, 5 (11.6%) had type IV block. Technical success was achieved in 41/43 (95.3%) patients (38, side-by-side SEMS placement; 3, SEMS-within-SEMS in Y fashion). Functional success was achieved in 39 patients (95.1%). No moderate-severe complications were reported. Median post-procedure hospitalization was five days. Median stent patency was 137 days (interquartile range [IQR] 80-214 days). Re-intervention was required in four patients (9.3%) after mean 295.7 days. Median overall survival was 153 days (IQR 108-234 days).

CONCLUSION

Endoscopic bilateral SEMS in complex malignant hilar obstruction has good outcomes in the form of technical success, functional success and stent patency. Survival is dismal despite optimal biliary drainage.

Potential significance of uncovered self‐expandable metal stents for distal malignant biliary obstruction: A propensity score‐adjusted competing risk regression analysis

Objectives

Selection criteria for self‐expandable metal stents (SEMSs) with or without cover during palliative treatment of distal malignant biliary obstruction (DMBO) remain unclear. We evaluated factors associated with time to recurrent biliary obstruction (TRBO) in fully covered SEMSs (FCSEMSs) and uncovered SEMSs (UCSEMSs).

Methods

We retrospectively analyzed consecutive patients with DMBO who received a SEMS. TRBO was determined using the Kaplan–Meier analysis, and complications were compared between the FCSEMS and UCSEMS groups. After TRBO‐associated factors were extracted using multivariate competing‐risks regression (CRR), propensity score‐adjusted CRRs were performed to verify their robustness.

Results

There were 180 patients (66 FCSEMSs and 114 UCSEMSs) enrolled in this study. There was no significant difference between median TRBO in the FCSEMS and UCSEMS groups (275 vs. 255 days, p = 0.67). Complications were more frequent in the FCSEMS than UCSEMS group (21.2% vs. 8.8%; p = 0.023). Multivariate CRR for TRBO‐associated factors revealed that “pancreatic ductal carcinoma (PDAC) treated with UCSEMS” was the only independent predictor of TRBO (p = 0.03). Similarly, the propensity score‐adjusted CRRs showed no significant difference in TRBO in “FCSEMS” vs “UCSEMS” (p = 0.96); however, there was a significant difference in “PDAC using UCSEMS” vs “other” (p = 0.043). In the palliative care group including any DMBO without chemotherapy, the first quartile of the TRBO of UCSEMS was 100 days.

Conclusions

UCSEMSs are a possible option for both patients with DMBO arising from PDAC and for patients with any DMBO receiving palliative care who should avoid SEMS‐related complications.

ACG Clinical Guideline: Diagnosis and Management of Biliary Strictures

A biliary stricture is an abnormal narrowing in the ductal drainage system of the liver that can result in clinically and physiologically relevant obstruction to the flow of bile. The most common and ominous etiology is malignancy, underscoring the importance of a high index of suspicion in the evaluation of this condition. The goals of care in patients with a biliary stricture are confirming or excluding malignancy (diagnosis) and reestablishing flow of bile to the duodenum (drainage); the approach to diagnosis and drainage varies according to anatomic location (extrahepatic vs perihilar). For extrahepatic strictures, endoscopic ultrasound-guided tissue acquisition is highly accurate and has become the diagnostic mainstay. In contrast, the diagnosis of perihilar strictures remains a challenge. Similarly, the drainage of extrahepatic strictures tends to be more straightforward and safer and less controversial than that of perihilar strictures. Recent evidence has provided some clarity in multiple important areas pertaining to biliary strictures, whereas several remaining controversies require additional research. The goal of this guideline is to provide practicing clinicians with the most evidence-based guidance on the approach to patients with extrahepatic and perihilar strictures, focusing on diagnosis and drainage.

Comparison of therapeutic efficacy and treatment costs of self-expandable metal stents and plastic stents for management of malignant biliary obstruction

BACKGROUND

According to the European Society of Gastrointestinal Endoscopy guidelines, self-expandable metal stents (SEMSs) are preferable to plastic stents (PSs) in the management of pancreatic cancer, regardless of cancer stage. The aim of this study was to compare the therapeutic efficacy and treatment costs of SEMS and PS in the management of malignant biliary obstruction.

METHODS

One hundred and thirty-five patients who underwent endoscopic stent placement were retrospectively enrolled and divided into PS (41 patients), primary SEMS (39 patients) and secondary SEMS (55 patients) groups. We determined the technical and functional success rate, stent patency, and cumulative treatment cost.

RESULTS

A total of 111 SEMSs and 153 PSs were placed with similar technical (100% vs. 98.69%) and functional success rate (90.10% vs. 86.27%) but with different stent patency (10.28 vs. 22.16 weeks; p < 0.001). Multiple PS implantations and larger stent diameter increased the length of stent patency compared to 7-Fr PSs (10.88 vs. 10.55 vs. 7.63 weeks, respectively). The cumulative treatment cost of patients with different survival times did not differ significantly between groups, however, among patients surviving 2-4 months it was higher in PS group than primary SEMS and secondary SEMS groups (2888€ vs. 2258€ vs. 2144€, respectively, p = 0.3369) due to increased number of biliary reintervention (2.08 ± 1.04 vs. 1.20 ± 0.42 vs. 1.50 ± 0.53; p < 0.0274) and longer hospital stay (15.77 ± 10.14 vs. 8.70 ± 7.70 vs. 8.50 ± 6.17 days, p = 0.0527).

CONCLUSIONS

In view of treatment costs, the consequences of illness, and the processes of the health care system, SEMS implantation is recommended regardless of patients' life expectancy.

Metal vs plastic stents for preoperative biliary drainage in patients with periampullary cancer: An updated systematic review and meta-analysis

BACKGROUND/PURPOSE

Metal stents (MS) are recommended for preoperative biliary drainage (PBD) in patients with periampullary cancer, but whether MS are superior in terms of re-intervention and direct cost is debatable. This study aimed to compare the effects of MS and PS on the outcomes of patients with periampullary cancer.

METHODS

For this random-effects meta-analysis, electronic databases were screened for randomized controlled trials (RCTs) published until January 2022. Subgroup analyses were performed basis on the center type and presence of NAC.

RESULTS

In this meta-analysis, seven RCTs (440 participants) were included. MS reduced re-interventions (risk ratio [RR] = 0.42, 95% confidence interval [CI] = 0.25-0.72) and direct costs (mean difference = -474 USD, 95% CI = -656 to -292). PBD-related complications (RR = 0.74, 95% CI = 0.32-1.71) and postoperative complications (RR = 0.73, 95% CI = 0.45-1.17) did not differ between MS and PS. Compared PS, MS reduced postoperative complications in high-volume centers (RR = 0.64, 95% CI = 0.49-0.84) and PBD-related complications in patients receiving NAC (RR = 0.29, 95% CI = 0.08-1.08).

CONCLUSIONS

Metal stents likely reduces re-interventions and direct costs. Further studies are needed to confirm the effects of MS on the outcomes.

Acetylsalicylic acid for metal stent in malignant distal common bile duct obstruction: A randomized controlled trial

BACKGROUND

Endoscopic biliary drainage is the treatment of choice for patients with malignant distal common bile duct obstruction. Self-expandable metal stents have clinical advantages including an increased duration of patency that may be prolonged by acetylsalicylic acid (ASA) use. The aim of this study was to investigate whether ASA had a positive effect on the patency of self-expandable metal stents compared with placebo.

METHODS

This prospective, multicenter, double-blinded, and randomized placebo-controlled trial was conducted from October 2017 to May 2020 in Korea. Patients who underwent palliative endoscopic biliary drainage with self-expandable metal stents for malignant distal bile duct obstruction were enrolled, and allocated to ASA treatment or placebo. The study outcomes were the rate of stent dysfunction at 6 months, duration of stent patency, risk factors for stent dysfunction, and any adverse events.

RESULTS

Interim analysis included 24 and 28 patients in the ASA and placebo groups, respectively. There was no significant difference between the ASA and placebo groups in stent dysfunction (25.0% vs. 20.7%, P = 0.761) or the duration of stent patency (150.97 ± 10.55 vs. 158.07 ± 8.70 days, P = 0.497). Six patients experienced suspected ASA-related adverse events, and there was one lethal case.

CONCLUSIONS

ASA did not prolong stent patency. This study was terminated early because of the possibility of serious adverse events related to ASA treatment of these patients receiving palliative care.

Endoscopic Management of Pancreatobiliary Malignancies

Pancreatobiliary malignancies have poor prognosis, and many patients are inoperable at the time of diagnosis. When surgical resection is impossible, systemic chemotherapy or radiotherapy is traditionally conducted with trial of immunotherapy or gene therapy lately. With the rapid development of endoscopic instruments and accessories in recent years, not only endoscopic early detection, characterization, and staging but also endoscopic palliative management of the pancreatobiliary malignancies is expanding the horizons. Endoscopic management is often preferred due to similar efficacy to surgical management with less morbidity. Here, we review the methodology and treatment outcome of various endoscopic management strategies in pancreatobiliary malignancies including endoscopic complication management, local palliative therapy, endoscopy-assisted therapy, and pain control utilizing endoscopic retrograde cholangiopancreatography or endoscopic ultrasound.

Preoperative biliary drainage for pancreatic cancer

Pancreatic adenocarcinoma is currently one of the leading causes of cancer-related morbidity and mortality with dismal long term survival after diagnosis. Nearly 85% of pancreatic cancer patients present with advanced disease precluding curative surgical resection. In those who are candidates for surgery, preoperative biliary drainage (PBD) has been developed since the 1960s in order to improve surgical outcomes. While obstructive jaundice in resectable pancreatic cancer has been traditionally treated before surgical resection in all patients, data over the past decade demonstrated increased perioperative complications and morbidity with systematic PBD compared to direct surgery. With new evidence of potential adverse events, the role of routine PBD is being reassessed. Current indications for PBD include cholangitis, delayed surgery, and relief of jaundice in patients planned to receive neoadjuvant therapy (NAT). NAT is being increasingly utilized in borderline resectable as well as resectable pancreatic cancer and a higher proportion of patients with likely require PBD in the future. The evidence for endoscopic retrograde cholangiopancreatography as first line for PBD is robust with supporting data from endoscopic ultrasound assisted biliary drainage. Self-expanding metal stent was shown to be cost-effective in recent studies without increase in morbidity compared to plastic stents in this setting. In this review, we will summarize the current evidence for PBD in patients with pancreatic cancer.

Use of stents in patients undergoing chemotherapy for borderline resectable pancreatic cancer-causing biliary obstruction while awaiting surgery: A cost-effectiveness analysis

Background and study aims  Biliary stenting is indicated to relieve obstruction from borderline resectable pancreatic cancer while patients receive preoperative neoadjuvant therapy. We compared the cost-effectiveness of plastic versus metal biliary stenting in this setting. Methods  A decision tree analysis compares two competing types of biliary stents (initially metal vs. initially plastic) to treat malignant distal biliary obstruction while receiving neoadjuvant therapy with different scenarios including possible complications as bridge till the patient undergoes curative surgical attempt. Using published information, effectiveness was chosen as the probability of successfully reaching a state of being ready for surgery once chemotherapy was completed. Costs (2018 US$) were based on national data. A third-party payer perspective was adopted, and sensitivity analyses were performed over a time-horizon of one year. Results  Initially inserting a metal versus a plastic biliary stent was more efficacious with a higher probability of reaching the readiness for surgery endpoint (96 % vs. 85 %), on average 18 days earlier while also being less expensive (US$ 9,304 vs. US$ 11,538). Sensitivity analyses confirmed robustness of these results across varying probability assumptions of plausible ranges and remained a dominant strategy even when lowering the willingness-to-pay threshold to US$ 1,000. Conclusions  Initial metal stenting to relieve malignant biliary obstruction from borderline resectable pancreatic cancer in patients undergoing neoadjuvant therapy prior to surgery is a dominant intervention in economic terms, when compared to initially inserting a plastic biliary stent as it results in a greater proportion of patients being fit for surgery earlier and at a lower cost.

Development of biliary stent applying the antibacterial activity of silver: A literature review

BACKGROUND

Endoscopic transpapillary stenting is commonly performed in patients with obstructive jaundice caused by a biliary stricture. Although the plastic stent (PS) is widely used for biliary drainage because of the low-cost and easy procedure, patency is short after placement in the bile duct because of the small diameter. Dysfunction of PS is primarily caused by biliary sludge that forms as a result of bacterial adhesion and subsequent biofilm formation on the inner surface of the stent. It is well known that silver ions have excellent antibacterial activity against a wide range of microorganisms.

OBJECTIVE

This review provides an overview and perspective of the significance of silver-coated biliary stents.

METHODS

We collected literature regarding silver-coated biliary stents, reviewed the current research/development status and discussed their possible usefulness.

RESULTS

To date, several in vivo/vitro studies evaluated the patency of silver-blended or silver-coated biliary stents. These studies suggested that the silver coating on a PS was likely to prolong the patency period.

CONCLUSION

The development of biliary stents using silver is expected to prolong stent patency and prevent frequent stent replacement.

ASGE guideline on the role of endoscopy in the management of malignant hilar obstruction

This clinical guideline from the American Society for Gastrointestinal Endoscopy (ASGE) provides an evidence-based approach for the management of patients with malignant hilar obstruction (MHO). This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework and addresses primary drainage modality (percutaneous transhepatic biliary drainage [PTBD] vs endoscopic biliary drainage [EBD]), drainage strategy (unilateral vs bilateral), and stent selection (plastic stent [PS] vs self-expandable metal stent [SEMS]). Regarding drainage modality, in patients with MHO undergoing drainage before potential resection or transplantation, the panel suggests against routine use of PTBD as first-line therapy compared with EBD. In patients with unresectable MHO undergoing palliative drainage, the panel suggests PTBD or EBD. The final decision should be based on patient preferences, disease characteristics, and local expertise. Regarding drainage strategy, in patients with unresectable MHO undergoing palliative stent placement, the panel suggests placement of bilateral stents compared with a unilateral stent in the absence of liver atrophy. Finally, regarding type of stent, in patients with unresectable MHO undergoing palliative stent placement, the panel suggests placing SEMSs or PSs. However, in patients who have a short life expectancy and who place high value on avoiding repeated interventions, the panel suggests using SEMSs compared with PSs. If optimal drainage strategy has not been established, the panel suggests placing PSs. This document clearly outlines the process, analyses, and decision processes used to reach the final recommendations and represents the official ASGE recommendations on the above topics.

Combined Versus Separate Sessions of Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography for the Diagnosis and Management of Pancreatic Ductal Adenocarcinoma with Biliary Obstruction

BACKGROUND

A single-procedure session combining EUS and ERCP (EUS/ERCP) for tissue diagnosis and biliary decompression for pancreatic duct adenocarcinoma (PDAC) is technically feasible. While EUS/ERCP may offer expedience and convenience over an approach of separate procedures sessions, the technical success and risk for complications of a combined approach is unclear.

AIMS

Compare the effectiveness and safety of EUS/ERCP versus separate session approaches for PDAC.

METHODS

Study patients (2010-2015) were identified within our ERCP database. Patients were analyzed in three groups based on approach: Group A: Single-session EUS-FNA and ERCP (EUS/ERCP), Group B: EUS-FNA followed by separate, subsequent ERCP (EUS then ERCP), and Group C: ERCP with/without separate EUS (ERCP ± EUS). Rates of technical success, number of procedures, complications, and time to initiation of PDAC therapies were compared between groups.

RESULTS

Two hundred patients met study criteria. EUS/ERCP approach (Group A) had a longer index procedure duration (median 66 min, p = 0.023). No differences were observed between Group A versus sequential procedure approaches (Groups B and C) for complications (p = 0.109) and success of EUS-FNA (p = 0.711) and ERCP (p = 0.109). Subgroup analysis (> 2 months of follow-up, not referred to hospice, n = 126) was performed. No differences were observed for stent failure (p = 0.307) or need for subsequent procedures (p = 0.220). EUS/ERCP (Group A) was associated with a shorter time to initiation of PDAC therapies (mean, 25.2 vs 42.7 days, p = 0.046).

CONCLUSIONS

EUS/ERCP approach has comparable rates of success and complications compared to separate, sequential approaches. An EUS/ERCP approach equates to shorter time interval to initiation of PDAC therapies.

Survival, stent patency, and cost-effectiveness of plastic biliary stent versus metal biliary stent for palliation in malignant biliary obstruction in a developing country tertiary hospital

Background and Aim

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.

Methods

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.

Results

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.

Conclusion

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.

One-step versus two-step distal self-expandable metal stent placement: A multicenter prospective randomized trial

BACKGROUND AND AIM

Two methods of transpapillary covered self-expandable metal stent (SEMS) placement are used for distal malignant biliary obstruction (MBO): after initial drainage by plastic stent (two-step method) and without previous drainage (one-step method).

METHODS

In total, 90 patients with unresectable pancreatic cancer and distal MBO were enrolled in this prospective multicenter randomized study and allocated to one-step (n = 45) and two-step (n = 45) groups. The main outcome was the time to recurrent biliary obstruction (TRBO). Secondary outcomes were the rates of early and late adverse events, survival time, the time required for bilirubin level reduction, and cost-effectiveness.

RESULTS

The median TRBO did not differ significantly between the one-step and two-step groups (not available vs 314 days, P = 0.134). SEMS migration occurred significantly more frequently in the two-step group (14.3% vs 0%, P = 0.026). No significant difference was observed between groups in early (7.3% vs 14.3%, P = 0.483) or late (12.2% and 11.9%, P = 1) adverse events other than RBO, survival time (P = 0.104), or the median number of days required to reach a bilirubin level considered to be acceptable for chemotherapy administration (<3 mg/dL; P = 0.881). The total costs of stent placement and reintervention were significantly lower in the one-step SEMS group (3347 vs 5465 US dollars, P < 0.001).

CONCLUSIONS

The superiority of TRBO with two-step SEMS placement was not demonstrated. One-step SEMS placement might be a promising method from the viewpoints of cost-effectiveness and less invasiveness (UMIN-CTR clinical trial registration number: UMIN000016010).

Biliary drainage in inoperable malignant biliary distal obstruction: A systematic review and meta-analysis

BACKGROUND

Endoscopic drainage remains the treatment of choice for unresectable or inoperable malignant distal biliary obstruction (MDBO).

AIM

To compare the safety and efficacy of plastic stent (PS) vs self-expanding metal stent (SEMS) placement for treatment of MDBO.

METHODS

This meta-analysis was developed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A comprehensive search was performed in MEDLINE, Cochrane, Embase, Latin American and Caribbean Health Sciences Literature, and grey literature to identify randomized clinical trials (RCTs) comparing clinical success, adverse events, stent dysfunction rate, reintervention rate, duration of stent patency, and mean survival. Risk difference (RD) and mean difference (MD) were calculated and heterogeneity was assessed with I² statistic. Subgroup analyses were performed by SEMS type.

RESULTS

Twelve RCTs were included in this study, totaling 1005 patients. There was no difference in clinical success (RD = -0.03, 95% confidence interval [CI]: -0.01, 0.07; I² = 0%), rate of adverse events (RD = -0.03, 95%CI: -0.10, 0.03; I² = 57%), and mean patient survival (MD = -0.63, 95%CI: -18.07, 19.33; I² = 54%) between SEMS vs PS placement. However, SEMS placement was associated with a lower rate of reintervention (RD = -0.34, 95%CI: -0.46, -0.22; I² = 57%) and longer duration of stent patency (MD = 125.77 d, 95%CI: 77.5, 174.01). Subgroup analyses revealed both covered and uncovered SEMS improved stent patency compared to PS (RD = 152.25, 95%CI: 37.42, 267.07; I² = 98% and RD = 101.5, 95%CI: 38.91, 164.09; I² = 98%; respectively). Stent dysfunction was higher in the covered SEMS group (RD = -0.21, 95%CI: -0.32, -0.1; I² = 205%), with no difference in the uncovered SEMS group (RD = -0.08, 95%CI: -0.56, 0.39; I² = 87%).

CONCLUSION

While both stent types possessed a similar clinical success rate, complication rate, and patient-associated mean survival for treatment of MDBO, SEMS were associated with a longer duration of stent patency compared to PS.

Newer Stents for Unresectable Malignant Distal Biliary Obstruction: Striving for Perfection!

Endoscopic biliary stenting is one of the most commonly used palliative procedure in patients with unresectable malignant distal biliary obstruction. Biliary stenting can be performed with either plastic or metallic stents. Stent occlusion and migration are important limitations of currently available stents. Variety of newer stents with varying designs and stent materials like stents with antimigratory properties, antireflux stents, drug-eluting stents, radioactive stents, and bioabsorbable stents are being developed to overcome the limitations of currently available stents. In this article, we are discussing two articles on the newer stent designs (plastic and metal stents) for biliary drainage in patients with unresectable malignant distal biliary obstruction.

Antireflux metal stent for biliary obstruction: Any benefits?

Endoscopic retrograde cholangiopancreatography with stent placement has been utilized as standard palliative management of distal malignant biliary obstruction (MBO). Compared to plastic stents, metal stents can provide longer-term relief of symptoms. When a large-bore metal stent is placed across the ampulla, patients are predisposed to the risk of cholangitis or stent dysfunction due to reflux of duodenal contents. To mitigate the risk of adverse events associated with the duodenobiliary reflux, efforts have been directed to development of antireflux metal stents (ARMSs). The antireflux property has been introduced through adding of an antireflux valve to the duodenal stent end. Evidence from clinical studies indicates that ARMSs may not only reduce the risk of ascending cholangitis during follow-up but also prolong stent patency time. However, the results of clinical studies testing ARMSs are inconsistent owing to heterogeneous designs of antireflux valves and stent bodies. Metal stents are increasingly indicated for benign biliary strictures and MBO in the setting of neoadjuvant chemotherapy, and therefore, research is warranted to evaluate ARMSs for those indications. Given that endoscopic ultrasound (EUS)-guided transmural biliary drainage has gained popularity, the optimal timing of placing an ARMS in relation to EUS-guided and percutaneous drainage should be investigated. Development and evaluation of ARMSs require an integrative approach utilizing phantom and animal models, measurements of stent mechanical properties, and in vivo functional study after stent placement. In this review article, we summarize updated evidence on ARMSs for MBO and discuss issues that should be addressed in future studies.

Comparison of plastic stent versus metal stent in preoperative biliary drainage for pancreatic head cancer with neoadjuvant chemoradiotherapy

BACKGROUND

While neoadjuvant chemotherapy and chemoradiotherapy (NACRT) for pancreatic head cancer are effective, preoperative endoscopic biliary drainage (EBD) is necessary for managing obstructive jaundice and cholangitis during the preoperative waiting period. Nevertheless, ideal choice of stent type is unclear. We compared plastic stents (PS) and metal stents (MS) in these situations.

METHODS

We retrospectively studied 43 patients who successfully underwent preoperative EBD prior to NACRT for pancreatic head cancer at a single institution. We divided patients into PS (n = 22) and MS (n = 21) groups. The primary outcome was the rate of re-interventional drainage rate before surgery. Secondary outcomes were rates of EBD-associated and postoperative complications and total costs in the pre- and perioperative periods.

RESULTS

The re-intervention rate was significantly greater in the PS group than in the MS group (95% vs 4.8%, respectively, P < 0.05). EBD-associated and postoperative complications were significantly less common in the MS group (P < 0.05). The average total preoperative medical costs were significantly lower in the MS group (PS vs MS: 528,597 vs 395,891 JPY, P = 0.004).

CONCLUSIONS

MS can be the first choice for EBD in patients undergoing NACRT for pancreatic head cancer. MS may be less costly overall.

Nationwide practice and outcomes of endoscopic biliary drainage in resectable pancreatic head and periampullary cancer

BACKGROUND

Guidelines advise self-expanding metal stents (SEMS) over plastic stents in preoperative endoscopic biliary drainage (EBD) for malignant extrahepatic biliary obstruction. This study aims to assess nationwide practice and outcomes.

METHODS

Patients with pancreatic head and periampullary cancer who underwent EBD before pancreatoduodenectomy were included from the Dutch Pancreatic Cancer Audit (2017-2018). Multivariable logistic and linear regression models were performed.

RESULTS

In total, 575/1056 patients (62.0%) underwent preoperative EBD: 246 SEMS (42.8%) and 329 plastic stents (57.2%). EBD-related complications were comparable between the groups (44/246 (17.9%) vs. 64/329 (19.5%), p = 0.607), including pancreatitis (22/246 (8.9%) vs. 25/329 (7.6%), p = 0.387). EBD-related cholangitis was reduced after SEMS placement (10/246 (4.1%) vs. 32/329 (9.7%), p = 0.043), which was confirmed in multivariable analysis (OR 0.36 95%CI 0.15-0.87, p = 0.023). Major postoperative complications did not differ (58/246 (23.6%) vs. 90/329 (27.4%), p = 0.316), whereas postoperative pancreatic fistula (24/246 (9.8%) vs. 61/329 (18.5%), p = 0.004; OR 0.50 95%CI 0.27-0.94, p = 0.031) and hospital stay (14.0 days vs. 17.4 days, p = 0.005; B 2.86 95%CI -5.16 to -0.57, p = 0.014) were less after SEMS placement.

CONCLUSION

This study found that preoperative EBD frequently involved plastic stents. SEMS seemed associated with lower risks of cholangitis and less postoperative pancreatic fistula, but without an increased pancreatitis risk.

Comparative Efficacy of Various Stents for Palliation in Patients with Malignant Extrahepatic Biliary Obstruction: A Systematic Review and Network Meta-Analysis

Although many studies have investigated the efficacy of stent placement for patients with malignant extrahepatic biliary obstruction, the clinical outcomes and adverse events of biliary stenting have not been comprehensively evaluated. We searched all relevant randomized-controlled trials that evaluated the comparative efficacy of biliary stents, including the plastic stents, uncovered self-expandable metal stents (SEMSs), and covered SEMSs in patients with malignant extrahepatic biliary obstructions. Twenty-one studies with 2326 patients were included. Both uncovered and covered SEMSs had a lower risk of recurrent biliary obstruction (RBO) compared to plastic stents (risk ratio (RR) (95% confidence interval [CI]): uncovered vs. plastic, 0.46 (0.35–0.62); covered vs. plastic, 0.46 (0.34–0.62)). A comparison of the groups using SEMSs revealed that tumor ingrowth was common in the uncovered SEMS group, while stent migration, tumor overgrowth, and occlusion by sludge were common in the covered SEMS group; however, the overall risk of RBO did not differ between these groups (RR (95% CI): uncovered vs. covered: 1.02 (0.80–1.30)). Although the main causes of RBO vary across stents, RBO risk was similar between uncovered and covered SEMS groups. Both SEMSs have superior efficacy in terms of RBO compared to plastic stents.

Advances in stent therapy for malignant biliary obstruction

Malignant biliary obstruction (MBO), result of pancreatobiliary diseases is a challenging condition. Most patients with MBO are inoperable at the time of diagnosis, and the disease is poorly controlled using external-beam radiotherapy and chemotherapy. Biliary stent therapy emerged as a promising strategy for alleviating MBO and prolonging life. However, physicians find it difficult to determine the optimal type of biliary stent for the palliation of MBO. Here, we review the safety and efficacy of available biliary stents, used alone or in combination with brachytherapy, photodynamic therapy and advanced chemotherapeutics, in patients with pancreatobiliary malignancies and put forward countermeasures involving stent obstruction. Furthermore, 3D-printing stents and nanoparticle-loaded stents have broad application prospects for fabricating tailor-made biliary stents.

Percutaneous transhepatic placement of plastic biliary stents: technical description and preliminary results

PURPOSE

To describe a novel technique of percutaneous transhepatic (PTH) placement of a plastic biliary stent (PBS), report the feasibility and safety of the technique, and present the preliminary results of a pilot study that included 32 patients with symptomatic obstructive jaundice (SOJ) treated with the technique.

MATERIALS AND METHODS

This was a prospective, single-arm, single-center, pilot study of a cohort of patients with the diagnosis of benign or malignant obstructive jaundice that underwent PTH placement of a PBS to relieve the obstruction.

RESULTS

Thirty-two patients were included, 16 men and 16 women (age range, 35-88 years). There were 26 malignant and six benign lesions. Cholangiocarcinoma was the most common tumor (n=13, 40.6%), followed by pancreatic adenocarcinoma (n=6, 18.75%) and metastasis (n=5, 15.6%). A total of 35 PBSs were placed in 32 procedures. The bile duct was accessed and drained to the right side in 18 cases, to the left side in 14 cases, and bilaterally in three cases. Technical success was achieved in 100% and clinical success in 93.7% of cases. Using a modified Bismuth-Cortelle classification system, type I was observed in nine patients, type II in nine patients, type III in six patients, and type IV in eight patients. The mean follow-up was 426.1 days for the total sample, and 349.4 days for patients with malignancy. Two complications were observed: transient hemobilia and cholangitis.

CONCLUSION

PTH placement of a PBS in patients with SOJ is feasible, safe, and effective.

Endoscopic retrograde cholangiopancreatography guided interventions in the management of pancreatic cancer

Pancreatic cancer is the leading cause of cancer-related morbidity and mortality with an overall five-year survival of less than 9% in the United States. At presentation, the majority of patients have painless jaundice, pruritis, and malaise, a triad that develops secondary to obstruction, which often occurs late in the course of the disease process. The technical advancements in radiological imaging and endoscopic interventions have played a crucial role in the diagnosis, staging, and management of patients with pancreatic cancer. Endoscopic retrograde cholangiopancreatography (ERCP)-guided diagnosis (with brush cytology, serial pancreatic juice aspiration cytologic examination technique, or biliary biopsy) and therapeutic interventions such as pancreatobiliary decompression, intraductal and relief of gastric outlet obstruction play a pivotal role in the management of advanced pancreatic cancer and are increasingly used due to improved morbidity and complication rates compared to surgical management. In this review, we highlight various ERCP-guided diagnostic and therapeutic interventions for the management of pancreatic cancer.

Endoscopic drainage in patients with malignant extrahepatic biliary obstruction: when and how

The question of when and how to drain a malignant biliary obstruction (MBO), both intrinsic or extrinsic, remains a controversial point among endoscopists. An important factor that influences the decision to drain an MBO or not is if the patient is a surgical candidate or not and, in the former case, if the patients must undergo neoadiuvant chemotherapy or not. Other questions arising during biliary drainage in MBO patients is which type of stent should be chosen, plastic or metal, and if endoscopic biliary sphincterotomy must be performed or not when a stent is placed. The present review attempts to answer these questions and summarizes the optimal approach toward patients with MBO based on the available evidence.

Effect of irreversible electroporation parameters and the presence of a metal stent on the electric field line pattern

The final ablation zone created with irreversible electroporation (IRE) depends on the size, shape and strength of the electric field that is influenced by several parameters. A profound understanding of the effect of IRE parameter alterations on the electric field are a prerequisite for a safe and effective treatment. Here, we demonstrate a semolina in castor oil model that enables visualization of the static electric field developed by a high-voltage generator between two needle-electrodes. We intuitively visualize the variation in electric field line pattern for selected IRE parameters; active needle length, inter-needle distance, applied voltage and presence of a nearby metal stent, by cameras in three dimensions. The observations were compared to and supported by two-dimensional numerical simulations of the electric field. Our semolina model visualizes the disturbance of the electric field by a metal stent, potentially leading to an incomplete tumour ablation between the needles. The reduction in electric field strength and the area at risk for incomplete tumour ablation are confirmed by the numerical simulations. The semolina model provides insight in the fundamental physics of the electric field, the effect of alterations in IRE parameter combinations and presence of a metal stent within the ablation zone.

Comparison of double-layer large-diameter and conventional small-diameter plastic stents for preoperative biliary drainage in resectable distal malignant biliary obstruction

The use of a plastic stent (PS) in resectable patients with distal malignant biliary obstruction (DMBO) is uncommon due to the high failure rate of this method. This study evaluated the efficacy and safety of a double-layer, large-diameter PS as a bridge to surgery compared with a conventional PS. This was a single-center retrospective cohort study. In total, 129 consecutive patients with DMBO underwent pancreaticoduodenectomy between January 2011 and March 2018. Fifty-five patients who preoperatively underwent plastic biliary drainage were enrolled. The patients were divided into two groups based on stent diameter: a large-diameter plastic stent (LPS) group and a small-diameter plastic stent (SPS) group. The primary endpoint was the stent patency period, and the secondary endpoint was the medical cost. Thirty-six patients received SPSs; 19 patients received LPSs. The patency rate until surgery was significantly higher in the LPS group than in the SPS group (89.5% vs. 41.7%, P = 0.0006). Multivariate analysis revealed that LPS use was significantly associated with sufficient stent patency. The total cost of LPS use was significantly lower than that of SPS use. LPSs had longer patency and reduced medical costs than SPSs. LPSs may be suitable for patients with DMBO who are scheduled to undergo surgery.

Retained biliary plastic stents - lest we forget

Prolonged indwelling of endoscopically placed biliary plastic stents may lead to complications. We conducted a retrospective analysis of patients who underwent endoscopic retrograde cholangio-pancreaticography (ERCP) at our centre in 2017 and were noted to have retained biliary plastic stents ( > 3 months after an index ERCP). A total of 127 patients had previously placed biliary plastic stents, out of which 45 (35.4%) were retained. The median age of the latter was 52 years (range = 22-79 years) with 27 (60%) patients being men. The median duration of the retained stents was 144 days (range = 94-3292 days). The majority of the patients were asymptomatic. However, 9 (20%) patients had cholangitis, 2 (4.4%) had choledocholithiasis, 2 (4.4%) had cholangitic abscess and 1 (2.2%) developed septicaemia. Fortunately, all these complications could be managed medically and endoscopically. Retention of biliary plastic stents is a problem often overlooked and underestimated in clinical practice. Various measures need to be instituted to create awareness of this entity to prevent undesirable outcomes.

Intraductal ablation by radiofrequency for inoperable biliopancreatic neoplasms with jaundice: experience at a regional hospital

The current treatment of choice for inoperable and/or unresectable biliopancreatic neoplasms complicated by jaundice is the placement of metal biliary stents. The most common complication is obstruction due to tumor growth. The application of radiofrequency ablation (RFA) is a new minimally invasive technique for the thermal ablation of the tumor tissue that causes biliary stenosis. Experience with RFA is scarce and there are few retrospective studies of clinical cases with a limited number of patients. Thus, there is little information on technical difficulty, safety and short-medium term monitoring. We present three cases, one cholangiocarcinoma and two pancreatic adenocarcinomas, with jaundice due to biliary stenosis. RFA was used with an ELRA catheter during endoscopic retrograde cholangiopancreatography (ERCP). The patients were monitored for ten months in order to assess the difficulty of treatment, efficacy and immediate and medium-term complications.

Metallic Stent Mesh Coated with Silver Nanoparticles Suppresses Stent-Induced Tissue Hyperplasia and Biliary Sludge in the Rabbit Extrahepatic Bile Duct

Recent therapeutic strategies to suppress restenosis after biliary stent placement are insufficient. Here, we demonstrate the usefulness of a self-expandable metal stent (SEMS), a stent mesh coated with silver nanoparticles (AgNPs), for suppression of both stent-induced tissue hyperplasia and biliary sludge formation in the rabbit bile duct. The AgNP-coated SEMSs were prepared using a simple bio-inspired surface modification process. Then, the prepared SEMSs were successfully placed in 22 of 24 rabbits. Sludge formation in the AgNP-coated SEMS groups was significantly decreased compared to the control group on gross findings. Cholangiographic and histologic examinations demonstrated significantly decreased tissue hyperplasia in the AgNP-coated SEMS groups compared with the control group (p < 0.05 for all). There were no differences between the AgNP-coated SEMS groups (p > 0.05 for all). However, in the group coated with the greatest concentration of AgNPs (Group D), submucosal fibrosis was thicker than in the other AgNP-coated groups (p < 0.05 for all). The AgNP-coated metallic stent mesh significantly suppressed stent-induced tissue hyperplasia and biliary sludge formation in the rabbit bile duct. Taken together, the AgNP coating strategy developed in this study could be widely utilized in non-vascular medical devices for anti-bacterial and anti-inflammatory responses.

Advances in the endoscopic management of malignant biliary obstruction

Biliary obstruction is common in pancreatobiliary malignancies and has a negative impact on the patient’s quality of life, postoperative complications, and survival rates. Particularly in the last decade, there has been enormous progress regarding the diagnostic and therapeutic options in patients with malignant biliary obstruction. Endoscopy has given a new insight in this direction and novel techniques have been developed for the better characterization and treatment of malignant strictures. We herein summarize the available data on the different endoscopic techniques, and clarify their role in the diagnosis and treatment of malignant biliary obstructive disease. Finally, we propose an algorithm that can facilitate management decisions in these patients.

Early malfunction of a biliary self-expandable metal stent with an antireflux valve: A case report

RATIONALE

Biliary drainage is essential to resolve jaundice in patients with malignant biliary obstruction. Recently, a biliary self-expandable metal stent (SEMS) with an antireflux valve was developed to prevent enteric-biliary reflux. Its antireflux valve was made of expanded polytetrafluoroethylene (ePTFE), a biostable and biocompatible material. Changes of the ePTFE membrane of medical devices are rarely reported in clinical practice.

PATIENT CONCERNS

A 59-year-old woman was admitted with a complaint of jaundice. Around 1 month before, she underwent endoscopic biliary stenting using a SEMS with an antireflux valve.

DIAGNOSIS

Acute cholangitis due to stent clogging was detected on abdominal computed tomography.

INTERVENTIONS

Endoscopic retrograde cholangiopancreatography and removal of the SEMS with deformity were performed.

OUTCOMES

The obstructive jaundice was rapidly resolved after the removal of the clogged stent.

LESSONS

Although the ePTFE membrane is widely used to make medical devices, unexpected changes could occur after the membrane is exposed to bile juice in the duodenum. When performing biliary stenting using a SEMS with an antireflux valve, both the risk of early malfunction and the benefit of the antireflux effect should be considered.

Aspirin for metal stent in malignant distal common bile duct obstruction (AIMS): study protocol for a multicenter randomized controlled trial

Background

Endoscopic retrograde biliary drainage (ERBD) is the treatment of choice for patients with malignant distal common bile duct (CBD) obstruction. Self-expandable metal stents (SEMS), which are commonly used in unresectable cases, have many clinical advantages, including longer stent patency. Although the expected patency of SEMS is around 8 months, it has recently been reported that the duration of SEMS’ patency in patients using aspirin is prolonged. Our study, therefore, aims to investigate the effect of aspirin on SEMS’ patency.

Methods/design

This is an investigator-initiated, prospective, multicenter, double-blind, randomized placebo-controlled trial that will be conducted from November 2017 in four tertiary centers in South Korea. We intend to include in our study 184 adult (aged ≥ 20 years) patients with malignant distal CBD obstruction for whom ERBD with SEMS was successfully performed. The patients will be randomly allocated to two groups, which will comprise patients who have either taken 100 mg aspirin or a placebo for 6 months after index ERBD. The primary outcome will be the rate of stent dysfunction, and the secondary outcomes will be the duration of patency, the rate of reintervention, and the occurrence of adverse events.

Discussion

The aspirin for metal stents in malignant distal common bile duct obstruction (AIMS) study should determine the efficacy of aspirin in maintaining metal-stent patency in patients with malignant distal CBD obstructive.

Trial registration

ClinicalTrials.gov, ID: NCT03279809. Registered on 5 September 2017.

Biliary stenting for hilar malignant biliary obstruction

Although endoscopic intervention is the mainstay for palliation of malignant biliary obstruction, a percutaneous approach has been preferred, particularly in patients with advanced high-grade hilar malignant biliary obstruction, because of the technical difficulty and risk of complications. However, recently, primary endoscopic palliation using plastic or metal stents has had higher technical and clinical success with fewer adverse events than the percutaneous approach. Endoscopic interventions are being done more and more frequently because of advances in metal stents, accessories, and techniques. However, several concerns, such as optimal stent type, number, and deployment method, remain to be resolved. Therefore, we reviewed the literature in order to identify the optimal biliary stenting strategy for patients with hilar malignant biliary obstruction, focusing on stent type (plastic vs metal), number (unilateral [single] vs bilateral [multiple]), and deployment method (stent-in-stent vs stent-by-stent).

Early Diagnosis And Management Of Malignant Distal Biliary Obstruction: A Review On Current Recommendations And Guidelines

Malignant biliary obstruction is a challenging condition, requiring a multimodal approach for both diagnosis and treatment. Pancreatic adenocarcinoma and cholangiocarcinoma are the leading causes of malignant distal biliary obstruction. Early diagnosis is difficult to establish as biliary obstruction can be the first presentation of the underlying disease, which can already be at an advanced stage. Consequently, the majority of patients (70%) with malignant distal biliary obstruction are unresectable at the time of diagnosis. The association of clinical findings, laboratory tests, imaging, and endoscopic modalities may help in identifying the underlying cause. Novel endoscopic techniques such as cholangioscopy, intraductal ultrasonography, or confocal laser endomicroscopy have been developed with promising results, but are not used in routine clinical practice. As the number of patients with malignant distal biliary obstruction who will undergo curative surgery is limited, endoscopy has a crucial role in palliation, to relieve biliary obstruction. According to the last European guidelines published in the management of biliary obstruction, self-expandable metal stents have a central place in biliary drainage compared to plastic stents. Endoscopic ultrasound has evolved impressively in the last decades. When standard techniques of biliary cannulation by endoscopic retrograde cholangiopancreatography fail, endoscopic ultrasound-guided biliary drainage is a good option compared to percutaneous drainage.

Safety and efficacy of a metal stent covered with a silicone membrane containing integrated silver particles in preventing biofilm and sludge formation in endoscopic drainage of malignant biliary obstruction: a phase 2 pilot study

BACKGROUND AND AIMS

Membrane-covered self-expandable metal stents (SEMSs) have been developed to prolong the patency of stents by reducing tissue hyperplasia or tumor ingrowth. However, their effectiveness is attenuated by stent clogging as a result of biofilm formation on the inner surface of the membrane. The aim of this pilot study was to evaluate the efficacy and safety of SEMSs covered with a silicone membrane containing integrated silver particles (Ag-P) in malignant distal biliary obstruction.

METHODS

Twenty-four patients who underwent SEMS placement because of malignant distal biliary obstruction were enrolled in this single-center pilot study. The main outcomes were technical success, clinical success, adverse events, stent patency, and survival.

RESULTS

The technical and clinical success rates were 100% and 91.7% (22 of 24), respectively. The rates of early and late adverse events were 22.7% and 36.4%, respectively. The primary reintervention rate was 27.3% (6 of 22). Only 1 case involving stent malfunction was associated with sludge impaction. Median stent patency was 179 days. During follow-up, there were no serious adverse events or mortality related to the stents or Ag-P. Serum and urine silver concentrations before and after stent placement and at 32 weeks after placement did not differ. All serum and urine silver concentrations were <3 μg/L (3 ppb) and 5 μg/L (5 ppb), respectively.

CONCLUSIONS

SEMSs covered with a silicone membrane containing integrated Ag-Ps may be effective and safe in malignant distal biliary obstruction. Stent dysfunction related to sludge impaction may be less frequent using this new stent. (Clinical Research Information Service identifier: KCT 0002310.).

Percutaneous stenting and chemotherapy for unresectable pancreatic cancer: Comparison of irradiation stents vs conventional metal stents

OBJECTIVES

Percutaneous stenting is a palliative method to relieve obstructive jaundice caused by unresectable pancreatic carcinoma. In this study, we aimed to compare the safety and efficacy of irradiation stents and conventional metal stents.

METHODS

A total of 32 patients who received irradiation stents or conventional metal stents to treat obstructive jaundice caused by locally advanced pancreatic cancer were included in this retrospective study. Chemotherapy using gemcitabine was performed after jaundice subsided. Stent patency, technical success, survival, and complications were compared between groups.

RESULTS

Seventeen patients were enrolled in the irradiation stent group (ISG), and 15 patients were enrolled in the uncovered stent group (USG). Median and mean stent patency time were 9.8 months (95% CI, 7.682-11.981) and 9.506 months (95% CI, 8.0-11.012) in the ISG, respectively, vs 8.8 months (95% CI, 6.528-11.072) and 7.62 months (95% CI, 5.917-9.323) in the USG, respectively (P = 0.019). Median and mean overall survival were 10.4 months (95% CI, 8.383-12.417) and 9.953 months (95% CI, 8.408-11.498), respectively, in the ISG vs 9.7 months (95% CI, 7.901-11.499) and 8.14 months (95% CI, 6.44-9.84), respectively, in the USG (P = 0.027).

CONCLUSIONS

Irradiation stents extend stent patency and overall survival compared with conventional biliary stents for the treatment of pancreatic carcinoma complicated by obstructive jaundice. Irradiation stents combined with chemotherapy may be a better choice for the treatment of obstructive jaundice caused by unresectable pancreatic carcinoma.

Antireflux covered metal stent for nonresectable distal malignant biliary obstruction: Multicenter randomized controlled trial

BACKGROUND AND AIM

An antireflux metal stent (ARMS) for nonresectable distal malignant biliary obstruction (MBO) may prevent recurrent biliary obstruction (RBO) as a result of duodenobiliary reflux and prolong time to RBO (TRBO). Superiority of ARMS over conventional covered self-expandable metal stents (SEMS) has not been fully examined.

METHODS

We conducted a multicenter randomized controlled trial to examine whether TRBO of an ARMS with a funnel-shaped valve was longer than that of a covered SEMS in SEMS-naïve patients. We enrolled 104 patients (52 patients per arm) at 11 hospitals in Japan. Secondary outcomes included causes of RBO, adverse events, and patient survival.

RESULTS

TRBO did not differ significantly between the ARMS and covered SEMS groups (median, 251 vs 351 days, respectively; P = 0.11). RBO as a result of biliary sludge or food impaction was observed in 13% and 9.8% of patients who received an ARMS and covered SEMS, respectively (P = 0.83). ARMS was associated with a higher rate of stent migration compared with the covered SEMS (31% vs 12%, P = 0.038). Overall rates of adverse events were 20% and 18% in the ARMS and covered SEMS groups, respectively (P = 0.97). No significant between-group difference in patient survival was observed (P = 0.26).

CONCLUSIONS

The current ARMS was not associated with longer TRBO compared with the covered SEMS. Modifications including addition of an anti-migration system are required to use the current ARMS as first-line palliative treatment of distal MBO (UMIN-CTR clinical trial registration number: UMIN000014784).

[Relief of Obstruction in the Management of Pancreatic Cancer]

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.

Diagnostic-therapeutic management of bile duct cancer

Biliary tract cancer, or cholangiocarcinoma, comprises a heterogeneous group of malignant tumors that can emerge at any part of the biliary tree. This group is the second most common type of primary liver cancer. Diagnosis is usually based on symptoms, which may be heterogeneous, and nonspecific biomarkers in serum and biopsy specimens, as well as on imaging techniques. Endoscopy-based diagnosis is essential, since it enables biopsy specimens to be taken. In addition, it can help with locoregional staging of distal tumors. Endoscopic retrograde cholangiopancreatography is a key technique for the evaluation and treatment of malignant biliary tumors. Correct staging of cholangiocarcinoma is essential in order to be able to determine the degree of resectability and assess the results of treatment. The tumor is staged based on the TNM classification of the American Joint Committee on Cancer. The approach will depend on the classification of the tumor. Thus, some patients with early-stage disease could benefit from surgery; complete surgical resection is the cornerstone of cure. However, only a minority of patients are diagnosed in the early stages and are suitable candidates for resection. In the subset of patients diagnosed with locally advanced or metastatic disease, chemotherapy has been used to improve outcome and to delay tumor progression. The approach to biliary tract tumors should be multidisciplinary, involving experienced endoscopists, oncologists, radiologists, and surgeons.

Palliative therapy in pancreatic cancer-palliative surgery

Pancreatic cancer is a highly lethal disease with a dismal prognosis. It will probably become the second leading cause of cancer-related death within the next decade in Western countries. Over 80% of patients undergo palliative treatment for unresectable pancreatic cancer due to locally advanced disease or metastases. Those patients often develop gastric outlet obstruction (GOO), obstructive jaundice and pain during the course of their disease. Symptoms such as vomiting, anorexia, pruritus and jaundice will impact the quality of life (QOL) and could delay the administration of the chemotherapy. Palliative therapy in pancreatic cancer aims to relieve the symptoms durably and to improve the QOL. Palliative surgery was traditionally considered as a gold standard with the "double by-pass" including biliary-digestive and gastro-jejunal anastomosis. However, since the development of endoscopic stenting and minimally invasive surgery, the choice of the best modalities remains debated. While there is still a place for surgical gastrojejunostomy (GJ) in case of duodenal or GOO, endoscopic biliary stenting during endoscopic retrograde cholangiopancreatography (ERCP) is now accepted as the gold standard in case of obstructive jaundice. In pain management, endoscopic ultrasound guided or percutaneous celiac plexus neurolysis is recommended. The selection of the best technique should consider the effectiveness and the morbidity of the treatment, the performance status of the patient and the disease stage. While endoscopic stenting is associated with earlier recovery and shorter length of stay, recurrence of symptoms and reintervention are less frequent after palliative surgery. Finally, controversy exists on whether to perform prophylactic palliative surgery in the absence of symptoms when unresectable disease is discovered during surgical exploration.