Usefulness of newly modified fully covered metallic stent of 12 mm in diameter and anti-migration feature for periampullary malignant biliary strictures: Comparison with conventional standard metal stent

Outcomes of multi-hole self-expandable metal stents versus fully covered self-expandable metal stents for malignant distal biliary obstruction in unresectable pancreatic cancer

Objectives

The multi-hole self-expandable metal stent (MHSEMS) is a novel SEMS with multiple small side holes on the covering membrane to prevent stent migration while minimizing tumor ingrowth. This study aimed to evaluate the clinical outcomes of MHSEMS in comparison with conventional covered SEMS (c-CMS).

Methods

Consecutive patients with unresectable pancreatic cancer who underwent initial SEMS placement (MHSEMS or c-CMS) for malignant distal biliary obstruction were analyzed. Technical success, clinical success, causes of recurrent biliary obstruction (RBO), non-RBO adverse events, time to RBO (TRBO), and endoscopic reintervention were compared between groups.

Results

A total of 65 patients were included (MHSEMS: 27, c-CMS: 38). The technical success, clinical success, and non-RBO adverse event rates were similar between groups. Although stent migration was less frequently observed in the MHSEMS group (0% vs. 17.6%, p = 0.032), overall RBO rates were similar between groups (53.8% vs. 55.9%, p > 0.99). The most common cause of RBO within 14 days in the MHSEMS group was non-occlusion cholangitis. Median TRBO was significantly shorter in the MHSEMS group (101 vs. 227 days, p = 0.030) and MHSEMS was an independent predictor for shorter TRBO in multivariate analysis (hazard ratio, 2.27; 95% confidence interval, 1.06-4.86; p = 0.034). Outcomes after endoscopic interventio were not significantly different between groups. Stent removal was successful in all attempted cases in both groups.

Conclusions

MHSEMS was associated with a significantly shorter TRBO compared to c-CMS. Further modifications of the present MHSEMS may be needed.

12-mm Versus 10-mm Metallic Stents for Malignant Biliary Obstructions: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Endoscopic drainage of malignant biliary obstruction using metal stents is widely used to treat obstructive jaundice. However, the occurrence of stent occlusion or migration raises the hypothesis using stents with larger diameters may be associated with better outcomes.

METHODS

PubMed, Embase, and Cochrane databases were systematically searched for studies comparing 10-mm vs. 12-mm covered metallic stents for recurrent unresectable biliary obstruction. The primary outcomes were recurrent biliary obstruction (RBO) and time to RBO (TRBO). Statistical analyses were performed using R software version 4.3.1. The risk ratio (RR) was used for binary outcomes, with their respective 95% confidence interval (CI). Heterogeneity was assessed using the Cochran Q test and I2 statistics.

RESULTS

We included five studies-one randomized clinical trial and four cohort studies-totaling 520 patients. Among these, 280 received 10-mm stents, while 240 were treated with 12-mm stents. The 12-mm stent is associated with a greater TRBO (HR 1.72; 95% CI 1.36 to 2.18), lower incidence of RBO (RR 0.59; 95% CI 0.44 to 0.78; I2=34%), and stent obstruction (RR 0.52; 95% CI 0.34 to 0.81; I2=33%). No significant differences were found for stent migration and adverse events rate between groups.

CONCLUSION

The 12-mm metallic stents significantly increase stent patency and reduce the incidence of RBO and stent obstruction in managing recurrent unresectable biliary obstruction, with no differences regarding stent migration and adverse events compared to 10-mm stents.

Endoscopic biliary drainage for distal bile duct obstruction due to pancreatic cancer

Approximately 60% of pancreatic cancers occur in the pancreatic head and may present as obstructive jaundice due to bile duct invasion. Obstructive jaundice often leads to poor general conditions and acute cholangitis, interfering with surgery and chemotherapy and requiring biliary drainage. The first choice of treatment for biliary drainage is the endoscopic transpapillary approach. In unresectable tumors, self-expandable metal stents (SEMSs) are most commonly used and are classified into uncovered and covered SEMSs. Recently, antireflux metal stents and large- or small-diameter SEMSs have become commercially available, and their usefulness has been reported. Plastic stents are infrequently used in patients with resectable biliary obstruction; however, owing to the recent trend in preoperative chemotherapy, SEMSs are frequently used because of the long time to recurrent biliary obstruction. Endoscopic ultrasound-guided biliary drainage (EUS-BD) is often performed in patients who are not eligible for the transpapillary approach, and favorable outcomes have been reported. Different EUS-BD techniques and specialized stents have been developed and can be safely used in high-volume centers. The indications for EUS-BD are expected to further expand in the future.

Efficacy and safety of a fully covered self-expandable metallic stent equipped with square flare in EUS-guided drainage/anastomosis: A multicenter retrospective study

Background and Objectives

Recent technological advances in interventional EUS have improved EUS-guided drainage/anastomosis (EUS-D/A), yet challenges remain. This study evaluated the safety and feasibility of a square flare fully covered self-expandable metallic stent (SF-FCSEMS) with anti-migration properties for EUS-D/A.

Methods

This retrospective cohort study was performed at 2 academic centers and analyzed patients who underwent SF-FCSEMS placement for EUS-D/A from April 2015 to November 2022. We have used an SF-FCSEMS that has a square flare at both ends that is 4 mm larger in diameter than the stent body, providing an anti-migration effect.

Results

Thirty-six patients (median age: 74 years), 41.6% male, were included. Malignancies accounted for 83.3%. Among the EUS-D/A procedure types, EUS-abscess drainage was performed in 52.8%, EUS-guided gallbladder drainage in 30.6%, and EUS-guided abscess drainage in 16.7%. The technical success rate was 97.2%, and the clinical success rate was 97.1%. The median procedure time was 36 minutes, with puncture tract dilation conducted in all cases. Adverse events occurred in 11.1%; recurrent symptoms were observed in 11.8%, with no migration. SF-FCSEMS removal was performed in 26.5% of patients during the follow-up period, with a median duration of 154 days. The total cost of deploying SF-FCSEMS was approximately 40% less than that of using lumen apposing metal stent.

Conclusions

EUS-D/A with an SF-FCSEMS, which has anti-migration properties, not only was effective and feasible in the present study but also demonstrated a cost advantage.

Effects of Clip Anchoring on Preventing Migration of Fully Covered Self-Expandable Metal Stent in Patients Undergoing Endoscopic Retrograde Cholangiopancreatography: A Multicenter, Randomized Controlled Study

INTRODUCTION

Fully covered self-expandable metal stents (FCSEMSs) are commonly placed in patients with biliary stricture during endoscopic retrograde cholangiopancreatography (ERCP). However, up to 40% of migration has been reported, resulting in treatment failure or the requirement for further intervention. Here, we aimed to investigate the effects of metal clip anchoring on preventing the migration of FCSEMS.

METHODS

Consecutive patients requiring placement of FCSEMS were included in this multicenter randomized trial. The enrolled patients were randomly assigned in a 1:1 ratio to receive clip anchoring (clip group) or not (control group). The primary outcome was the migration rate at 6 months after stent insertion. The secondary outcomes were the rates of proximal and distal migration and stent-related adverse events. The analysis followed the intention-to-treat principle.

RESULTS

From February 2020 to November 2022, 180 patients with biliary stricture were enrolled, with 90 in each group. The baseline characteristics were comparable between the 2 groups. The overall rate of stent migration at 6 months was significantly lower in the clip group compared with the control group (16.7% vs 30.0%, P = 0.030). The proximal and distal migration rates were similar in the 2 groups (2.2% vs 5.6%, P = 0.205; 14.4% vs 22.2%, P = 0.070). Notably, none of the patients (0/8) who received 2 or more clips experienced stent migration. There were no significant differences in stent-related adverse events between the 2 groups.

DISCUSSION

Our data suggest that clip-assisted anchoring is an effective and safe method for preventing migration of FCSEMS without increasing the adverse events.

Risk factors for recurrent biliary obstruction following endoscopic biliary stenting in patients with unresectable ampullary cancer: A multicenter retrospective study

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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 and complications of inoperable malignant distal biliary obstruction treatment by metallic stents: fully covered or uncovered?

Obstructive jaundice caused by malignant distal biliary obstruction is a common clinical symptom in patients with inoperable biliary-pancreatic cancer. Endoscopic retrograde cholangiopancreatography (ERCP)-guided stent implantation is an effective treatment for obstructive jaundice. Internal stent drainage is more physiologic and associated with a better quality of life than external stent drainage methods such as percutaneous transhepatic gallbladder drainage or percutaneous transhepatic cholangiodrainage. Self-expanding metallic stents, which may be covered and uncovered, are commonly used. However, some uncertainties remain regarding the selection of metallic stents, including drainage patency time, clinical effect, stent migration, and post-operative complications such as pancreatitis, bleeding, and cholecystitis. This review aims to summarize the current progress and controversies surrounding the use of covered or uncovered metallic stents in inoperable common biliary obstruction via ERCP.

Effect of ursodeoxycholic acid after self-expandable metal stent placement in malignant distal biliary obstruction: a propensity score-matched cohort analysis

BACKGROUND AND AIMS

Sludge occlusion is a primary reason for recurrent biliary obstruction (RBO) after self-expandable metallic stent (SEMS) placement. However, the efficacy of ursodeoxycholic acid (UDCA) for SEMS occlusion remains unexplored to date. This study aimed to evaluate the efficacy of UDCA after SEMS placement for malignant distal biliary obstruction (MDBO).

METHODS

Three hundred fifty-four patients were included, of which 60 received UDCA. Additionally, we conducted a propensity score-matched cohort analysis on 110 patients with SEMS placement for MDBO to reduce selection bias. Patients were categorized into 2 groups of 55 each, based on whether they received UDCA. In the UDCA group, the treatment was administered for more than a month. The primary endpoint was the time to RBO (TRBO) after SEMS placement. The secondary endpoint was to evaluate SEMS occlusion rate and early adverse events (AEs).

RESULTS

The cumulative SEMS occlusion rate was 41.8% and 18.2% in the groups with and without UDCA, respectively (P = .0119). Median TRBO was significantly longer in the control group than in the UDCA group (528 vs 154 days, P = .0381). In the multivariate analysis, UDCA administration was identified as the independent risk factor for reducing TRBO (hazard ratio, 2.28; 95% confidence interval, 1.06-4.88; P = .0348). The overall early AE rate showed insignificant differences between groups.

CONCLUSIONS

Administering UDCA after SEMS placement was not efficacious for prolonging the TRBO in MDBO. Moreover, administering UDCA beyond a month might increase the risk of stent sludge occlusion. (Clinical trial registration number: UMIN000046862.).

Double bare metal stent deployment combined with intraductal radiofrequency ablation for malignant distal biliary obstruction: a prospective pilot study

Although uncovered self-expandable metal stents (SEMSs) possess certain advantages such as averting cystic duct obstruction and stent migration, they are susceptible to ingrowth occlusion. The combination of the double bare stent (DBS) and endobiliary radiofrequency ablation (RFA) may reduce ingrowth. Hence, this study aimed to examine the utility of this method for the treatment of unresectable malignant distal biliary obstruction (MDBO). This prospective, single-center, pilot study enrolled 51 patients who met the eligibility criteria between February 2020 and January 2022. The study outcomes included technical success, clinical success, recurrent biliary obstruction (RBO), and other adverse events (AE) besides RBO associated with DBS placement with RFA for MDBO. The technical success rate was 98.0% (50/51). Clinical success was achieved in all patients in whom technical success was achieved. The rates of early and late AEs were 5.9% (3/51) and 8.0% (4/50), respectively. The incidence rate of RBO was 38.0% (19/50). Sludge occlusion, ingrowth occlusion, and overgrowth occlusion occurred in 26.0% (13/50), 8.0% (4/50), and 2.0% (1/50) of patients, respectively (the main cause of RBO was undeterminable in 1 patient). The median time to RBO was 241 days. DBS with RFA showed good technical feasibility, good long-term outcomes, acceptable AE rates, and most importantly, a low ingrowth occlusion rate when employed for the treatment of MDBO.

Prolonged patency of fully covered self-expandable metal stents with an externally anchored plastic stent in distal malignant biliary obstruction

BACKGROUND : Fully covered self-expandable metal stents (FCSEMSs) are widely used for endoscopic treatment of distal malignant biliary obstruction (dMBO). We aimed to assess the efficacy of anchoring an external plastic stent to an FCSEMS in dMBO. METHODS : A multicenter retrospective cohort study was performed in patients with dMBO to compare stent patency between FCSEMSs and FCSEMSs with an externally anchored plastic stent (EPS). For external anchoring, a 7-Fr double-pigtail plastic stent (DPPS) was placed first in the bile duct, then an FCSEMS was deployed side-by-side. RESULTS : Among a total of 185 patients, 65 had an FCSEMS alone and 120 had an FCSEMS with an EPS. The median stent patency was significantly longer in the FCSEMS with an EPS group than in the FCSEMS only group (342 vs. 240 days; P = 0.04). The rate of stent migration was significantly lower in the FCSEMS with an EPS group than in the FCSEMS only group (10.8 % vs. 27.7 %; P = 0.01). There were no significant differences in the rates of stent occlusion and adverse events between the two groups. CONCLUSIONS : A novel and simple technique of anchoring an external plastic stent may decrease the risk of FCSEMS migration and prolong stent patency, without significantly increasing the adverse events rate in dMBO.

EUS-guided cholecystoduodenostomy using novel dumbbell-shaped fully covered metal stent (with video)

Highlight Atalla and colleagues present a novel dumbbell-shaped fully covered self-expandable metal stent which, with its anti-migration property and relatively lower cost, is a feasible and cost-effective option as an alternative to lumen-apposing metal stents for endoscopic ultrasound-guided transduodenal gallbladder drainage for acute cholecystitis in patients who are ineligible for surgery.

Comparing the 14-mm uncovered and 10-mm covered metal stents in patients with distal biliary obstruction caused by unresectable pancreatic cancer: a multicenter retrospective study

BACKGROUND

Endoscopic biliary drainage using metal stent (MSs) is an established palliative treatment for patients with unresectable malignant distal biliary obstruction (MDBO). However, a major drawback of MS is recurrent biliary obstruction (RBO). Uncovered MSs with a diameter of 14 mm (UMS-14) were developed to overcome this. We aimed to compare the clinical outcomes of UMS-14 with those of conventional covered MSs having a diameter of 10 mm (CMS-10).

METHODS

Consecutive patients with MDBO caused by unresectable pancreatic cancer, who underwent UMS-14 or CMS-10 placement at two tertiary-care centers, were retrospectively examined according to the Tokyo Criteria 2014.

RESULTS

Two hundred and thirty-eight patients who underwent UMS-14 (the UMS-14 group, n = 80) or CMS-10 (the CMS-10 group, n = 158) over a 62-month period were included. The technical and clinical success rates were similar between the two groups. RBO occurred in 20 (25%) and 59 (37%) patients of the UMS-14 and CMS-10 groups, respectively (p = 0.06). Median time till RBO was significantly longer in the UMS-14 group than in the CMS-10 group (not reached vs. 290 days, p = 0.04). Multivariate analysis revealed that CMS-10 placement was an independent risk factor for RBO (hazard ratio: 1.66, 95% confidence interval: 1.00-2.76). The incidence of early complications, including pancreatitis, and the overall survival (UMS-14 vs. CMS-10: 169 vs. 167 days, p = 0.83) were comparable between the two groups.

CONCLUSIONS

UMS-14 stents were safe and effective for treating patients with MDBO secondary to unresectable pancreatic cancer. The insertion of UMS-14 is recommended, because it is less likely to get occluded as compared to CMS-10.

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.

Feasibility and efficacy evaluation of metallic biliary stents eluting gemcitabine and cisplatin for extrahepatic cholangiocarcinoma

BACKGROUND

Effective endoscopic management is fundamental for the treatment of extrahepatic cholangiocarcinoma (ECC). However, current biliary stents that are widely used in clinical practice showed no antitumor effect. Drug-eluting stents (DESs) may achieve a combination of local chemotherapy and biliary drainage to prolong stent patency and improve prognosis.

AIM

To develop novel DESs coated with gemcitabine (GEM) and cisplatin (CIS)-coloaded nanofilms that can maintain the continuous and long-term release of antitumor agents in the bile duct to inhibit tumor growth and reduce systemic toxicity.

METHODS

Stents coated with different drug-eluting components were prepared by the mixed electrospinning method, with poly-L-lactide-caprolactone (PLCL) as the drug-loaded nanofiber membrane and GEM and/or CIS as the antitumor agents. Four different DESs were manufactured with four drug-loading ratios (5%, 10%, 15%, and 20%), including bare-loaded (PLCL-0), single-drug-loaded (PLCL-GEM and PLCL-CIS), and dual-drug-loaded (PLCL-GC) stents. The drug release property, antitumor activity, and biocompatibility were evaluated in vitro and in vivo to confirm the feasibility and efficacy of this novel DES for ECC.

RESULTS

The in vitro drug release study showed the stable, continuous release of both GEM and CIS, which was sustained for over 30 d without an obvious initial burst, and a higher drug-loaded content induced a lower release rate. The drug-loading ratio of 10% was used for further experiments due to its ideal inhibitory efficiency and relatively low toxicity. All drug-loaded nanofilms effectively inhibited the growth of EGI-1 cells in vitro and the tumor xenografts of nude mice in vivo; in addition, the dual-loaded nanofilm (PLCL-GC) had a significantly better effect than the single-drug-loaded nanofilms (P < 0.05). No significant differences in the serological analysis (P > 0.05) or histopathological changes were observed between the single-loaded and drug-loaded nanofilms after stent placement in the normal porcine biliary tract.

CONCLUSION

This novel PLCL-GEM and CIS-eluting stent maintains continuous, stable drug release locally and inhibits tumor growth effectively in vitro and in vivo. It can also be used safely in normal porcine bile ducts. We anticipate that it might be considered an alternative strategy for the palliative therapy of ECC patients.