Endoscopic-ultrasound-guided biliary drainage with placement of electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction:Updated meta-analysis

BACKGROUND Endoscopic ultrasound-guided biliary drainage using electrocautery-enhanced(ECE)delivery of lumen-apposing metal stent(LAMS)is gradually being re-cognized as a viable palliative technique for malignant biliary obstruction after endoscopic retrograde cholangiopancreatography(ERCP)failure.However,most of the studies that have assessed its efficacy and safety were small and hetero-geneous.Prior meta-analyses of six or fewer studies that were published 2 years ago were therefore underpowered to yield convincing evidence.AIM To update the efficacy and safety of ECE-LAMS for treatment of biliary ob-struction after ERCP failure.METHODS We searched PubMed,EMBASE,and Scopus databases from the inception of the ECE technique to May 13,2022.Primary outcome measure was pooled technical success rate,and secondary outcomes were pooled rates of clinical success,re-intervention,and adverse events.Meta-analysis was performed using a random-effects model following Freeman-Tukey double-arcsine transformation in R soft-ware(version 4.1.3).RESULTS Fourteen eligible studies involving 620 participants were ultimately included.The pooled rate of technical success was 96.7%,and clinical success was 91.0%.Adverse events were reported in 17.5%of patients.Overall reinter-vention rate was 7.3%.Subgroup analyses showed results were generally consistent.CONCLUSION ECE-LAMS has favorable success with acceptable adverse events in relieving biliary obstruction when ERCP is impossible.The consistency of results across most subgroups suggested that this is a generalizable approach.

Defining failure of endoluminal biliary drainage in the era of endoscopic ultrasound and lumen apposing metal stents

The role of endoscopy in pathologies of the bile duct and gallbladder has seen notable advancements over the past two decades.With advancements in stent technology,such as the development of lumen-apposing metal stents,and adoption of endoscopic ultrasound and electrosurgical principles in therapeutic endoscopy,what was once considered endoscopic failure has transformed into failure of an approach that could be salvaged by a second-or third-line endoscopic strategy.Incorporation of these advancements in routine patient care will require formal training and multidisciplinary acceptance of established techniques and collaboration for advancement of experimental techniques to generate robust evidence that can be utilized to serve patients to the best of our ability.

Revolutionizing palliative care:Electrocautery-enhanced lumenapposing metal stents in endoscopic-ultrasound-guided biliary drainage for malignant obstructions

Patients with malignant biliary obstruction,following endoscopic retrograde cholangiopancreatography(ERCP)failure could be referred for endoscopicultrasound-guided biliary drainage through electrocautery-enhanced(ECE)lumen-apposing metal stent(LAMS)placement.However,the efficacy and safety of ECE-LAMS in this scenario have remained debatable due to minimal scientific evidence.The current confirmed 91.0%clinical success,96.7%technical success,7.3%reintervention rate,and 17.5%adverse events,following the treatment of malignant biliary obstruction with ECE-LAMS delivery.Finally,ECE-LAMS proved to be a generalizable strategy for managing biliary obstruction for patients who were excluded from ERCP.

Endoscopic ultrasound-guided biliary drainage using electrocauteryenhanced lumen-apposing metal stent for malignant biliary obstruction:A promising procedure

In this editorial,we comment on the article by Peng et al.Palliative drainage for biliary obstruction resulting from unresectable malignant lesions includes internal and external drainage.The procedures of biliary drainage are usually guided by fluoroscopy or transcutaneous ultrasound,endoscopic ultrasound(EUS),or both.Endoscopic retrograde cholangiopancreatography(ERCP)has been primarily recommended for the management of biliary obstruction,while EUS-guided biliary drainage and percutaneous transhepatic biliary drainage(PTBD)are alternative choices for cases where ERCP has failed or is impossible.PTBD is limited by shortcomings of a higher rate of adverse events,more reinterventions,and severe complications.EUS-guided biliary drainage has a lower rate of adverse events than PTBD.EUS-guided biliary drainage with electrocautery-enhanced lumen-apposing metal stent(ECE-LAMS)enables EUS-guided biliaryenteric anastomosis to be performed in a single step and does not require prior bile duct puncture or a guidewire.The present meta-analysis showed that ECELAMS has a high efficacy and safety in relieving biliary obstruction in general,although the results of LAMS depending on the site of biliary obstruction.This study has highlighted the latest advances with a larger sample-based comprehensive analysis.

Unveiling the potential of electrocautery-enhanced lumen-apposing metal stents in endoscopic ultrasound-guided biliary drainage

This editorial delves into Peng et al's article,published in the World Journal of Gastrointestinal Surgery.Peng et al's meta-analysis investigates the effectiveness of electrocautery-enhanced lumen-apposing metal stents(ECE-LAMS)in ultrasound-guided biliary drainage for alleviating malignant biliary obstruction.Examining 14 studies encompassing 620 participants,the research underscores a robust technical success rate of 96.7%,highlighting the efficacy of ECE-LAMS,particularly in challenging cases which have failed endoscopic retrograde cholangio pancreatography.A clinical success rate of 91.0% underscores its impact on symptom alleviation,while a reasonably tolerable adverse event rate of 17.5% is observed.However,the 7.3% re-intervention rate stresses the need for post-procedural monitoring.Subgroup analyses validate consistent outcomes,bolstering the applicability of ECE-LAMS.These findings advocate for the adoption of ECELAMS as an appropriate approach for biliary palliation,urging further exploration in real-world clinical contexts.They offer valuable insights for optimizing interventions targeting malignant biliary obstruction management.

Role of endoscopic-ultrasound-guided biliary drainage with electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction

In this editorial,we discuss the article by Peng et al in the recent issue of the World Journal of Gastrointestinal Surgery,focusing on the evolving role of endoscopicultrasound-guided biliary drainage(EUS-BD)with electrocautery lumen apposing metal stent(LAMS)for distal malignant biliary obstruction.Therapeutic endoscopy has rapidly advanced in decompression techniques,with growing evidence of its safety and efficacy surpassing percutaneous and surgical approaches.While endoscopic retrograde cholangiopancreatography(ERCP)has been the gold standard for biliary decompression,its failure rate approaches 10.0%,prompting the exploration of alternatives like EUS-BD.This random-effects meta-analysis demonstrated high technical and clinical success of over 90.0% and an adverse event rate of 17.5%,mainly in the form of stent dysfunction.Outcomes based on stent size were not reported but the majority used 6 mm and 8 mm stents.As the body of literature continues to demonstrate the effectiveness of this technique,the challenges of stent dysfunction need to be addressed in future studies.One strategy that has shown promise is placement of double-pigtail stents,only 18% received the prophylactic intervention in this study.We expect this to improve with time as the technique continues to be refined and standardized.The results above establish EUS-BD with LAMS as a reliable alternative after failed ERCP and considering EUS to ERCP upfront in the same session is an effective strategy.Given the promising results,studies must explore the role of EUS-BD as first-line therapy for biliary decompression.

Endoscopic management of benign biliary strictures:Looking for the best stent to place

Benign biliary strictures(BBS)might occur due to different pancreaticobiliary conditions.The etiology and location of biliary strictures are responsible of a wide array of clinical manifestations.The endoscopic approach endoscopic retrograde cholangiopancreatography represents the first-line treatment for BBS,considering interventional radiology and surgery when endoscopic treatment fails or it is not suitable.The purpose of this review is to provide an overview of possible endoscopic treatments for the optimal management of this subset of patients.

Different percutaneous transhepatic biliary stent placements and catheter drainage in the treatment of middle and low malignant biliary obstruction

BACKGROUND For cases of middle and low biliary obstruction with left and right hepatic duct dilatation,the type of approach and whether different approaches affect the difficulty of puncture operation and intraoperative and postoperative complications have not been discussed in detail.AIM To compare the efficacy of different percutaneous transhepatic biliary stent placements and catheter drainage in treating middle and low biliary obstruction.METHODS A retrospective analysis was performed on the medical records of 424 patients with middle and low biliary obstruction who underwent percutaneous liver puncture biliary stent placement and catheter drainage at the Department of Interventional Radiology,Shaanxi Provincial People’s Hospital between March 2016 and March 2022.Based on the puncture path,patients were categorized into two groups:Subxiphoid left hepatic lobe approach group(Group A,224 cases)and right intercostal,right hepatic lobe approach group(Group B,200 cases).Liver function improvement,postoperative biliary bleeding incidence,postoperative pain duration,and abdominal effusion leakage around the drainage tube were compared between the two groups at 3 d and 1 wk after the surgery.Patient survival time was recorded during follow-up.RESULTS All 424 surgeries were successful without adverse events.Group A comprised 224 cases,and Group B had 200 cases.There was no statistically significant difference in basic data between Group A and Group B(P>0.05).No significant difference in postoperative biliary bleeding incidence was observed between the groups(P>0.05).The decreased rates for total bilirubin(Group A:69.23±4.50,Group B:63.79±5.65),direct bilirubin(Group A:79.30±11.19,Group B:63.62±5.64),and alkaline phosphatase(Group A:60.51±12.23,Group B:42.68±23.56)in the 1st wk after surgery were significantly faster in Group A than in Group B.The decreased rate of gamma-glutamyl transpeptidase was also significantly faster in Group A at both 3 d(Group A:40.56±10.32,Group B:32.22±5.12)and 1 wk(Group A:73.19±7.05,Group B:58.81±18.98)after surgery(P<0.05).Group A experienced significantly less peritoneal effusion leakage around the drainage tube than Group B(P<0.05).The patient survival rate was higher in Group A compared to Group B(P<0.05).CONCLUSION In treating jaundice patients with middle and low biliary obstruction,a percutaneous left liver puncture demonstrated better clinical efficacy than a percutaneous right liver puncture.

Endoscopic ultrasound-guided biliary drainage after failed endoscopic retrograde cholangiopancreatography: The road is open for almighty biliopancreatic endoscopists!

Commentary on the article written and published by Peng et al,investigating the role of endoscopic ultrasound(EUS)-guided biliary drainage for palliation of malignant biliary obstruction after failed endoscopic retrograde cholangiopan-creatography(ERCP).For 40 years endoscopic biliary drainage was synonymous with ERCP,and EUS was used mainly for diagnostic purposes.The advent of therapeutic EUS has revolutionized the field,especially with the development of a novel device such as electrocautery-enhanced lumen-apposing metal stents.Complete biliopancreatic endoscopists with both skills in ERCP and in interven-tional EUS,would be ideally suited to ensure patients the best drainage technique according to each individual situation.

Metal stent implantation for palliation of malignant biliary obstruction-a report of 57 cases

AIMS To report the first experience in China in the treatment of malignant biliary obstruction with expand- able metal stent which allows the insertion of an endo- prosthesis as large as one cm in diameter. METHODS Between April 1994 and May 1996,we implanted expandable metal stents in 57 patients with incurable malignant biliary obstruction,among whom 54 underwent endoscopic procedure and the other 3 re- ceived percutaneous transhepatic placement. RESULTS Insertion of the stent following guidewire positioning was successful in 95% of the patients. Two patients developed cholangitis after stent insertion and were successfully treated with conservative treatment. The jaundice was eliminated completely in 21 cases and markedly decreased in 23 cases within 2 weeks af- ter placement of the stent. Nine patients,however, had late cholangitis due to stent failure after a median interval of 14 days. Twenty-three cases underwent na- sobiliary transient drainage and 3 underwent plastic stent transient drainage prior to metal stent insertion. Transient drainage was believed to have the advan- tages of drainage pre-assessment and infection controlling. CONCLUSIONS Our results show that expandable metal stent is suitable for the irresectable malignant choledochal stenosis. It can eliminate the jaundice and improve the patient's life quality. To get the highest benefit,however,the indication should be strictly selected. And to get long-term patency,the proximal and distal end of the stent proceeding the tumor should be no shorter than 2cm. In the case of hilar cancer, Bismuth classification is greatly helpful for the choice of drainage site.

The Cost-effectiveness Analysis of Percutaneous Transhepatic Metal Versus Plastic Biliary Stent Implantation for Treating Malignant Biliary Obstruction (Multiple Center Investigation)

Objective: To compare metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction in cost-effectiveness ratio (CER). Methods: Percutaneous transhepatic self-expandable metal stent (MS, n=61) or 10F plastic stent (PS, n=34) implantation was performed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival and stent patency rates of the patients in the two groups. CERs of two groups were calculated. The main indexes were CERsurvival period (total cost/median survival period), CERpatency period (total cost/median patency period). Results: The total costs of treatment were 53177±3139 yuan (RMB) in MS group and 42564±4950 yuan (RMB) in PS group respectively (P>0.05). CER in MS group was superior to that in PS group (CERsurvival period was 237.4 yuan /d vs 452.6 yuan /d, respectively; CERpatency period was 231.2 yuan /d vs 472.9 yuan /d, respectively). Conclusion: The metal stent implantation is superior to the plastic stent in the CER for treatment of malignant biliary obstruction.

Endoscopic stenting for inoperable malignant biliary obstruction: A systematic review and meta-analysis

AIM: To analyze through meta-analyses the benefits of two types of stents in the inoperable malignant biliary obstruction.METHODS: A systematic review of randomized clinical trials(RCT) was conducted, with the last update on March 2015, using EMBASE, CINAHL(EBSCO), MEDLINE, LILACS/CENTRAL(BVS), SCOPUS, CAPES(Brazil), and gray literature. Information of the selected studies was extracted in sight of six outcomes: primarily regarding dysfunction, complication and reintervention rates; and secondarily costs, survival, and patency time. The data about characteristics of trial participants, inclusion and exclusion criteria and types of stents were also extracted. The bias was mainly assessed through the JADAD scale. This meta-analysis was registered in the PROSPERO database by the number CRD42014015078. The analysis of the absolute risk of the outcomes was performed using the software Rev Man, by computing risk differences(RD) of dichotomous variables and mean differences(MD) of continuous variables. Data on RD and MD for each primary outcome were calculated using the MantelHaenszel test and inconsistency was qualified and reported in χ2 and the Higgins method(I2). Sensitivity analysis was performed when heterogeneity was higher than 50%, a subsequent assay was done and other findings were compiled. Student's t-test was used for the comparison of weighted arithmetic means regarding secondary outcomes.RESULTS: Initial searching identified 3660 studies; 3539 were excluded through title, repetition, and/or abstract, while 121 studies were fully assessed and were excluded mainly because they did not compare self-expanding metal stents(SEMS) and plastic stents(PS), leading to thirteen RCT selected, with 13 articles and 1133 subjects meta-analyzed. The mean age was 69.5 years old, that were affected mostly by bile duct(proximal) and pancreatic tumors(distal). The preferred SEMS diameter used was the 10 mm(30 Fr) and the preferred PS diameter used was 10 Fr. In the metaanalysis, SEMS had lower overall stent dysfunction compared to PS(21.6% vs 46.8%, P < 0.00001) and fewer re-interventions(21.6% vs 56.6%, P < 0.00001), with no difference in complications(13.7% vs 15.9%, P = 0.16). In the secondary analysis, the mean survival rate was higher in the SEMS group(182 d vs 150 d, P < 0.0001), with a higher patency period(250 d vs 124 d, P < 0.0001) and a lower cost per patient(4193.98 vs 4728.65 Euros, P < 0.0985).CONCLUSION: SEMS are associated with lower stent dysfunction, lower re-intervention rates, better survival, and higher patency time. Complications and costs showed no difference.

New antireflux plastic stent for patients with distal malignant biliary obstruction

BACKGROUND Endoscopic biliary stenting is a well-established palliative treatment for patients with unresectable distal malignant biliary obstruction(MBO). However, the main problem with stent placement is the relatively short duration of stent patency.Although self-expanding metal stents(SEMSs) have a longer patency period than plastic stents(PSs), the higher costs limit the wide use of SEMSs. A PS with an antireflux valve is an attractive idea to prolong stent patency, but no ideal design for an antireflux PS(ARPS) has been proposed. We developed a new ARPS with a "duckbilled" valve attached to the duodenal end of the stent.AIM To compare the patency of ARPSs with that of traditional PSs(TPSs) in patients with unresectable distal MBO.METHODS We conducted a single-center, prospective, randomized, controlled, double-blind study. This study was conducted at the West China Hospital of Sichuan University. Consecutive patients with extrahepatic MBO were enrolled prospectively. Eligible patients were randomly assigned to receive either an ARPS or a TPS. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The primary outcome was the duration of stent patency. Secondary outcomes included the rate of technical success, the rate of clinical success,adverse events, and patient survival.RESULTS Between February 2016 and December 2017, 38 patients were randomly assigned to two groups, with 19 patients in each group, to receive ARPSs or TPSs. Stent insertion was technically successful in all patients. There were no significant differences between the two groups in the rates of clinical success or the rates of early or late adverse events(P = 0.660, 1.000, and 1.000, respectively). The median duration of stent patency in the ARPS group was 285 d [interquartile range(IQR),170], which was significantly longer than that in the TPS group(median, 130 d;IQR, 90, P = 0.005). No significant difference in patient survival was noted between the two groups(P = 0.900).CONCLUSION The new ARPS is safe and effective for the palliation of unresectable distal MBO,and has a significantly longer stent patency than a TPS.

Characterization of biofilms in biliary stents and potential factors involved in occlusion

AIM To quantify the components in biofilms and analyze the predisposing factors involved in occlusion of biliary stents. METHODS In a prospective study conducted from April 2011 to March 2014 at a tertiary care hospital, all consecutive patients who required endoscopic biliary stent exchange/removal were included. Etiology of the biliary disease was diagnosed by imaging, cytology and on follow-up. Clinical details of patients with biliary stent retrieval were noted. All extracted stents were collected in sterile containers and immediatelyprocessed for quantification of biofilm proteins and polysaccharides. Molecular identification of commonly known and unknown bacteria was performed by polymerase chain reaction and density gradient gel electrophoresis methods. RESULTS Eighty one patients(41 males) with age range of 20-86 years were studied. The underlying causes for stent insertion were bile duct stones(n = 46; 56.8%) benign stricture(n = 29; 35.8%) and malignancy(n = 6; 7.4%) with cholangitis in 50(61.7%) patients. The retrieved stent sizes were 7 Fr(n = 62; 76.5%) and 10 Fr(n = 19; 23.5%) with 65 days median insertion duration. Polybacterial consortia were detected in 90.1% of the stents. The most common bacteria identified by polymerase chain reaction alone and/or sequencing were Pseudomonas(n = 38), Citrobacter(n = 23), Klebsiella(n = 22), Staphylococcus(n = 20), Serratia(n = 16), Escherichia coli(n = 14), Streptococcus(n = 13), Enterococcus(n = 13), Aeromonas(n = 12), Proteus(n = 10) and Enterobacter(n = 9). Protein concentration according to gender(0.547 ± 0.242 mg/ml vs 0.458 ± 0.259 mg/ml; P = 0.115) as well as age > 60 years and < 60 years(0.468 ± 0.295 mg/ml vs 0.386 ± 0.238 mg/ml; P = 0.205) was non-significant. However, polysaccharide concentration was significant both according to gender(0.052 ± 0.021 mg/ml vs 0.049 ± 0.016 mg/ml; P < 0.0001) and age(0.051 ± 0.026 mg/ml vs 0.038 ± 0.016 mg/ml; P < 0.011). Protein concentration in the biofilm was significantly higher(0.555 ± 0.225 mg/ml vs 0.419 ± 0.276 mg/ml; P = 0.018) in patients with cholangitis, lower(0.356 ± 0.252 mg/ml vs 0.541 ± 0.238 mg/ml; P = 0.005) in the 10 Fr group than the 7 Fr group, and significantly higher(0.609 ± 0.240 mg/ml vs 0.476 ± 0.251 mg/ml; P = 0.060) in stents of ≥ 6 mo of indwelling time. However presence/absence of cholangitis, size of stent, indication of stent insertion and indwelling time did not affect the quantity of polysaccharide concentration.CONCLUSION Plastic stents retrieved from patients with biliary tract disease showed polymicrobial organisms with higher protein content among patients with cholangitis and those with smaller diameter stents. longer indwelling duration had more biofilm formation.

Lumen-apposing metal stents for malignant biliary obstruction: Is this the ultimate horizon of our experience?

In the last years, endoscopic ultrasonography (EUS) has evolved from a purely diagnostic technique to a more and more complex interventional procedure, with the possibility to perform several type of therapeutic interventions. Among these, EUS-guided biliary drainage (BD) is gaining popularity as a therapeutic approach after failed endoscopic retrograde cholangiopancreatography in distal malignant biliary obstruction (MBO), due to the avoidance of external drainage, a lower rate of adverse events and re-interventions, and lower costs compared to percutaneous trans-hepatic BD. Initially, devices created for luminal procedures (e.g., luminal biliary stents) have been adapted to the new trans-luminal EUSguided interventions, with predictable shortcomings in technical success, outcome and adverse events. More recently, new metal stents specifically designed for transluminal drainage, namely lumen-apposing metal stents (LAMS), have been made available for EUS-guided procedures. An electrocautery enhanced delivery system (EC-LAMS), which allows direct access of the delivery system to the target lumen, has subsequently simplified the classic multi-step procedure of EUS-guided drainages. EUS-BD using LAMS and ECLAMS has been demonstrated effective and safe, and currently seems one of the most performing techniques for EUS-BD. In this Review, we summarize the evolution of the EUS-BD in distal MBO, focusing on the novelty of LAMS and analyzing the unresolved questions about the possible role of EUS as the first therapeutic option to achieve BD in this setting of patients.

Biliary stenting with or without sphincterotomy for malignant biliary obstruction:A meta-analysis

AIM: To investigate the benefits of endoscopic sphincterotomy (EST) before stent placement by meta-analysis of randomized controlled trials (RCTs).

Evaluation of fully covered self-expanding metal stents in benign biliary strictures and bile leaks

AIM: To investigate the use of fully covered metal stents in benign biliary strictures (BBS) and bile leaks. METHODS: We studied 17 patients, at Harbor-UCLA Medical center (Los Angeles), with BBS (n=12) and bile leaks (n=5) from July 2007 to February 2012 that had received placement of fully covered self-expanding metal stents (FCSEMs). Fourteen patients had endoscopic placement of VIABIL (Conmed, Utica, New York, United States) stents and three had Wallflex (Boston Scientific, Mass) stents. FCSEMS were 8 mm or 10 mm in diameter and 4 cm to 10 cm in length. Patients were followed at regular intervals to evaluate for symptoms and liver function tests. FCSEMS were removed after 4 or more weeks. Resolution of BBS and leak was documented cholangiographically following stent removal. Stent patency can be defined as adequate bile and contrast flow from the stent and into the ampulla during endoscopic retrograde cholangiopancreatography (ERCP) without clinical signs and/or symptoms of biliary obstruction. Criterion for bile leak resolution at ERCP is defined as absence of contrast extravasation from the common bile duct, cystic duct remanent, or gall blad-der fossa. Rate of complications such as migration, and instent occlusion were recorded. Failure of endoscopic therapy was defined as persistent biliary stenosis or continuous biliary leakage after 12 mo of stent placement. RESULTS: All 17 patients underwent successful FC- SEMS placement and removal. Etiologies of BBS included: cholecystectomies (n=8), cholelithiasis (n=2), hepatic artery compression (n=1), pancreatitis (n=2), and Whipple procedure (n=1). All bile leaks occurred following cholecystectomy. The anatomic location of BBS varied: distal common bile duct (n=7), common hepatic duct (n=1), hepaticojejunal anastomosis (n=2), right intrahepatic duct (n=1), and choledochoduo-denal anastomatic junction (n=1). All bile leaks were found to be at the cystic duct. Twelve of 17 patients had failed prior stent placement or exchange. Resolution of the biliary strictures and bile leaks was achieved in 16 of 17 patients (94%). The overall median stent time was 63 d (range 27-251 d). The median stent time for the BBS group and bile leak group was 62 ± 58 d (range 27-199 d) and 92 ± 81 d (range 48-251 d), respectively. All 17 patients underwent successful FCSEMS removal. Long term follow-up was obtained for a median of 575 d (range 28-1435 d). Complications occurred in 5 of 17 patients (29%) and included: migration (n=2), stent clogging (n=1), cholangitis (n=1), and sepsis with hepatic abscess (n=1). CONCLUSION: Placement of fully covered self-expanding metal stents may be used in the management of benign biliary strictures and bile leaks with a low rate of complications.

Randomized trial in malignant biliary obstruction:Plastic vs partially covered metal stents

AIM:To compare efficacy and complications of par-tially covered self-expandable metal stent(pcSEMS)to plastic stent(PS)in patients treated for malignant,infrahilar biliary obstruction.METHODS:Multicenter prospective randomized clinical trial with treatment allocation to a pcWallstent(SEMS)or a 10 French PS.Palliative patients aged≥18,for infrahilar malignant biliary obstruction and a Karnofsky performance scale index>60%from 6 participating North American university centers.Primary endpoint was time to stent failure,with secondary outcomes of death,adverse events,Karnofsky performance score and short-form-36 scale administered on a three-monthly basis for up to 2 years.Survival analyses were performed for stent failure and death,with Cox proportional hazards regression models to determine significant predictive characteristics.RESULTS:Eighty-five patients were accrued over 37mo,42 were randomized to the SEMS group and 83patients were available for analyses.Time to stent failure was 385.3±52.5 d in the SEMS and 153.3±19.8 d in the PS group,P=0.006.Time to death did not differ between groups(192.3±23.4 d for SEMS vs211.5±28.0 d for PS,P=0.70).The only significant predictor was treatment allocation,relating to the time to stent failure(P=0.01).Amongst other measured outcomes,only cholangitis differed,being more common in the PS group(4.9%vs 24.5%,P=0.029).The small number of patients in follow-up limits longitudinal assessments of performance and quality of life.From an initially planned 120 patients,only 85 patients were recruited.CONCLUSION:Partially covered SEMS result in a longer duration till stent failure without increased complication rates,yet without accompanying measurable benefits in survival,performance,or quality of life.

Percutaneous transhepatic metal versus plastic biliary stent in treating malignant biliary obstruction: a multiple center investigation

OBJECTIVE: To compare the efficacy of metal versus plastic biliary stent implantation in the treatment of malignant biliary obstruction. METHODS: Percutaneous transhepatic self-expandable metal stent (MS, n=61) and 10F plastic stent (PS, n=34) were placed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival of the patients and the rates of stent patency. RESULTS: The 30-day mortality rate was lower in the MS group (6/61, 9.8%) than in the PS group (9/34, 26.5%, P<0.05). The 30-day reobstruction rate and the complication rate were 15.0%, 16.4% in the MS group and 32. 4%, 29. 4% in the PS group, respectively (P<0. 01). The median patency period of stents and median survival period of the patients were 230 days, 224 days in the MS group and 90 days, 94 days in the PS group, respectively (P<0. 01). CONCLUSION: Metal stent is clinically superior to plastic stent in the treatment of malignant biliary obstruction.

Biliary and pancreatic stenting:Devices and insertiontechniques in therapeutic endoscopic retrogradecholangiopancreatography and endoscopic ultrasonography

Stents are tubular devices made of plastic or metal. Endoscopic stenting is the most common treatment for obstruction of the common bile duct or of the main pancreatic duct, but also employed for the treatment of bilio-pancreatic leakages, for preventing post- endoscopic retrograde cholangiopancreatography pancreatitis and to drain the gallbladder and pancreatic fluid collections. Recent progresses in techniques of stent insertion and metal stent design are represented by new, fullycovered lumen apposing metal stents. These stents are specifically designed for transmural drainage, with a saddle-shape design and bilateral flanges, to provide lumen-to-lumen anchoring, reducing the risk of migration and leakage. This review is an update of the technique of stent insertion and metal stent deployment, of the most recent data available on stent types and characteristics and the new applications for biliopancreatic stents.