Comparative performance of uncoated, self-expanding metal biliary stents of different designs in 2 diameters: final results of an international multicenter, randomized, controlled trial

Long slim versus conventional self-expandable metallic stent in bilateral endoscopic side-by-side deployment for unresectable malignant hilar biliary obstruction

BACKGROUND AND AIMS

The goal of this study was to compare the advantages of long slim metal stents (LSMSs) versus conventional metal stents in bilateral endoscopic side-by-side (SBS) deployment for malignant hilar biliary obstruction (MHBO).

METHODS

A total of 140 consecutive patients with MHBO treated by endoscopic bilateral SBS deployment at a high-volume tertiary referral center were analyzed retrospectively; this included 50 patients in the LSMS group and the other 90 patients in the conventional SBS group as control. Propensity score matching at a 1:2 ratio was used to reduce selection bias. The primary outcome was stent patency.

RESULTS

After propensity score matching, no significant difference was observed in stent patency (267 vs 268 days; P = .923) or overall survival (225 vs 211 days; P = .883) between the 2 groups. The technical success rate was 100% in both groups, and the clinical success rate was 91.1% in the LSMS group and 92.9% in the control group (P = .735). Early and late adverse events were similar (24.4% vs 34.3%, P = .423; 42.2% vs 38.6%, P = .697); the procedure time and bilateral metal stenting time in the LSMS group were significantly shorter (41.0 minutes vs 57.5 minutes, P = .000; 19.0 minutes vs 28.5 minutes, P = .000). The success rate of endoscopic bilateral revisionary stent insertion in the LSMS group was also higher (100% vs 33.3%; P = .000).

CONCLUSIONS

Bilateral LSMS placement is a viable option for patients with MHBO. It includes advantages of less operative difficulty and easier future re-intervention over conventional SBS stenting.

Potential of 6-mm-diameter fully covered self-expandable metal stents for unresectable malignant distal biliary obstruction: a propensity score-matched study

BACKGROUND/AIMS

To date, only thinner-diameter metal stents have been evaluated for unresectable malignant distal biliary obstruction (UR-MDBO). This study investigated the outcomes and optimal cohorts for a 6-mm-diameter fully covered self-expandable metal stent (FCSEMS) compared with those for a 10-mm-diameter FCSEMS.

METHODS

This single-center retrospective cohort study included patients who underwent initial transpapillary metal stenting for UR-MDBO. Propensity score matching (1:1) analysis was performed.

RESULTS

Of 133/68 patients who underwent 6-mm/10-mm-diameter FCSEMS deployment, 59 in each group were selected. The median time to recurrent biliary obstruction was not significantly different between the groups (p=0.46). In contrast, use of the 6-mm-diameter FCSEMS resulted in a significantly reduced incidence of stent-related adverse events (AEs) (p=0.016), especially cholecystitis (p=0.032), and patients aged <70 years were particularly affected by this significant reduction. Among the patients in the end-stage cohort who were unable to continue chemotherapy after FCSEMS deployment, the free rate of stent-related events, including recurrent biliary obstruction and stent-related AEs, was significantly higher in the 6-mm group (p=0.027).

CONCLUSIONS

For UR-MDBO, a 6-mm-diameter FCSEMS can be an optimal and safe option in the younger cohort with a relatively high risk of AEs and in the end-stage cohort requiring safer drainage without interference from stent-related events during times of poor prognosis.

EUS- versus ERCP-guided biliary drainage for malignant biliary obstruction: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Increasing evidence supports EUS-guided biliary drainage (EUS-BD) as a potential alternative to ERCP-guided biliary drainage (ERCP-BD) in the primary treatment of malignant biliary obstruction (MBO). This systematic review and meta-analysis aimed to compare the efficacy and safety of both techniques as the initial approach for MBO.

METHODS

We systematically searched in MEDLINE, Embase, and Cochrane databases for randomized controlled trials comparing both techniques and reporting at least one of the outcomes of interest. The pooled estimates were calculated using the random-effects model, and I2 statistics were used to evaluate heterogeneity.

RESULTS

We included 6 randomized controlled trials (577 patients). There were no significant differences between both groups in terms of stent patency (mean difference [MD], 8.18 days; 95% confidence interval [CI], -22.55 to 38.91), procedure time (MD, -6.31 minutes; 95% CI, -12.68 to 0.06), and survival (MD, 4.59 days; 95% CI, -34.23 to 43.40). Technical success (risk ratio [RR], 1.04; 95% CI, 0.96-1.13), clinical success (RR, 1.02; 95% CI, 0.96-1.08), overall adverse events (RR, 0.58; 95% CI, 0.24-1.43), and cholangitis (RR, 1.19; 95% CI, 0.39-3.61) were also similar between groups. However, the hospital stay was significantly shorter (MD, -1.03 days; 95% CI, -1.53 to -0.53), and the risk of reintervention (RR, 0.57; 95% CI, 0.37-0.88), postprocedure pancreatitis (RR, 0.15; 95% CI, 0.03-0.66), and tumor ingrowth/overgrowth (RR, 0.28; 95% CI, 0.11-0.70) were significantly lower with EUS-BD.

CONCLUSIONS

EUS-BD and ERCP-BD had similar efficacy and safety as the initial approach for MBO. However, EUS-BD had a significantly lower risk of reintervention, postprocedure pancreatitis, tumor ingrowth/overgrowth, and reduced hospital stay.

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.).

Characteristics of four commonly used self-expanding biliary stents: an in vitro study

BACKGROUND

Knowledge of the characteristics of self-expanding metal stents (SEMSs) is essential during selection process to ensure the best therapeutic outcomes for patients with malignant biliary obstruction. The aim of this study was to evaluate the characteristics of four commonly used SEMSs.

METHODS

This in vitro study analyzed the radial force (RF), crush resistance (CR), axial force (AF), conformability, surface quality, foreshortening, and radiopacity of the following SEMSs: uncovered Wallflex™, EGIS single bare, Zilver 635®, and E-Luminexx™. Two samples of each SEMS type were included in this study, all having identical specifications with a diameter of 10 mm and a length of 6 cm. One sample from each type was analyzed for surface quality, followed by CR, conformability, and foreshortening. The other sample was analyzed for radiopacity, followed by RF and AF.

RESULTS

The uncovered Wallflex™ exhibited low RF, high CR, high AF, good conformability, poor surface quality, high foreshortening, and good radiopacity. The EGIS single bare demonstrated high RF, high CR, low AF, moderate conformability, good surface quality, high foreshortening, and poor radiopacity. The Zilver 635® displayed moderate RF, low CR, low AF, moderate conformability, moderate surface quality, no foreshortening, and good radiopacity. The E-Luminexx™ showed high RF, moderate CR, high AF, poor conformability, poor surface quality, no foreshortening, and good radiopacity.

CONCLUSIONS

There was considerable variation in the characteristics among the four evaluated SEMSs. These characteristics should be carefully considered during selection to ensure optimal therapeutic outcomes for patients.

RELEVANCE STATEMENT

The selection of self-expanding metal stents for treating malignant biliary obstruction requires careful consideration of various characteristics, including their radial force, crush resistance, axial force, conformability, surface quality, foreshortening, and radiopacity.

KEY POINTS

• The characteristics of self-expanding metal stents (SEMSs) can vary considerably. • Specific situations may warrant the use of SEMSs with particular characteristics over others. • Characteristics of SEMSs must be considered during selection for optimal outcomes.

Comparable Efficacy of Laser-Cut and Braided Self Expanding Metallic Biliary Stent: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

In patients with unresectable malignant biliary obstruction (MBO), endoscopic biliary drainage is the treatment of choice. Self-expanding metallic stents (SEMS) are mainly used for this purpose, and data is limited on the comparative outcomes of laser-cut versus braided SEMS. Herein, we performed the first systematic review and meta-analysis to study the effectiveness and safety of braided and laser-cut SEMS in MBO.

METHODS

Multiple databases, including Medline, Scopus, and Embase, were searched (in May 2022) using specific terms for studies evaluating the outcomes of braided and laser-cut SEMS in MBO. Outcomes of interest were technical and clinical success, recurrent biliary obstruction, and adverse events. Standard meta-analysis methods were employed using the random-effects model. I2% heterogeneity was used to assess the heterogeneity.

RESULTS

Seven studies were included in the final analysis. (Laser-cut: 271 patients, 46% females, mean age 70 years; and braided: 282 patients, 47% females, mean age 72 years). The pooled rate of technical success and clinical success with laser-cut SEMS was 99% (95% CI [95-99; I2 = 0%]), 86% [60-96; I2 = 74%], and 98% [96-99; I2 = 0%], 89% [74-95; I2 = 78%] with braided. The pooled rate of recurrent biliary obstruction with laser-cut SEMS was 26% [14-43; I2 = 88%] and 12% [5-27; I2 = 56%) with braided. Pooled total adverse events were 11% [5-21; I2 = 77%] in laser-cut and 12% [6-24; I2 = 63%] in braided.

CONCLUSION

Our meta-analysis demonstrates similar clinical outcomes with laser-cut and braided SEMS in MBO. Given the comparable performance, a cost-effectiveness analysis might help in choosing one type versus another in patients with MBO.

Effect of radiofrequency ablation in addition to biliary stent on overall survival and stent patency in malignant biliary obstruction: an updated systematic review and meta-analysis

OBJECTIVES

Radiofrequency ablation (RFA) is used in addition to stent placement to manage extrahepatic malignant biliary obstruction. We aimed to study the effect of RFA on overall survival (OS) and stent patency in malignant biliary obstruction.

METHODS

A comprehensive literature search was performed from inception to May 2022 for all studies measuring the effect of RFA plus stents compared to stents placement only on OS and stent patency in patients with malignant biliary obstruction. We measured differences in OS, stent patency, and odds of adverse events. A random effect model was used to pool data for stent patency, OS, and adverse event.

RESULTS

A total of 17 studies (14 observational and 3 RCT) containing 1766 patients were included in the analysis. The weighted pooled mean survival difference was 58.5 days [95% confidence interval (CI): 32.6-84.4, I2 = 71%] in favor of the RFA treatment group. The weighted mean difference in stent patency was better in the RFA plus stent group by 45.3 days (95% CI: 30.1-60.5, I2 = 16.4%) compared to stent only group. The pooled odds of adverse events were the same in both groups [odds ratio (OR) 1.52, 95% CI: 0.96-2.43, I2 = 59%], and no serious adverse event was seen in either group, or no death reported secondary to RFA procedure. No difference in stent patency based on procedure type, including percutaneous transhepatic cholangiography versus endoscopic retrograde cholangiopancreatography (P = 0.06), and an underline cause of bile duct obstruction was found (P = 0.261).

CONCLUSION

RFA treatment, in addition to stent placement in malignant biliary obstruction, potentially improves OS and stent patency duration.

Novel anti-reflux biliary metal stent with a distal tapered end for distal malignant biliary obstruction: a feasibility study

Background and study aims  We developed a self-expandable metallic stent (SEMS) with a distal tapered end to reproduce the physiological bile flow with a pressure gradient due to the difference in the diameter. We aimed to evaluate the safety and efficacy of the newly developed distal tapered covered metal stent (TMS) for distal malignant biliary obstruction (DMBO). Patients and methods  This single-center, prospective, single-arm study was conducted in patients with DMBO. The primary endpoint was time to recurrent biliary obstruction (TRBO), and the secondary endpoints were the survival time and incidence of adverse events (AEs). Results  Thirty-five patients (15 men, 20 women; median age, 81 years [range: 53-92]) were enrolled between December 2017 and December 2019. The primary diseases were pancreatic head cancer in 25 cases, bile duct cancer in eight cases, and ampullary cancer in two cases. TMS was successfully placed in all cases. Acute cholecystitis occurred as an early AE (within 30 days) in two cases (5.7 %). The median TRBO was 503 days, median survival time was 239 days. RBO was observed in 10 cases (28.6 %), and the causes were distal migration in six cases, proximal migration in two cases, biliary sludge in one case, and tumor overgrowth in one case. Conclusions  Endoscopic placement of the newly developed TMS in patients with DMBO is technically feasible and safe, and the TRBO was remarkably long. The anti-reflux mechanism based on the difference in diameter may be effective, and a randomized controlled trial with a conventional SEMS is required.

Effectiveness of a new approach to minimally invasive surgery in palliative treatment of patients with distal malignant biliary obstruction

BACKGROUND

Palliative endoscopic biliary drainage is the primary treatment option for the management of patients with jaundice which results from distal malignant biliary obstruction (DMBO). In this group of patients, decompression of the bile duct (BD) allows for pain reduction, symptom relief, chemotherapy administration, improved quality of life, and increased survival rate. To reduce the unfavorable effects of BD decompression, minimally invasive surgical techniques require continuous improvement.

AIM

To develop a technique for internal-external biliary-jejunal drainage (IEBJD) and assess its effectiveness in comparison to other minimally invasive procedures in the palliative treatment of patients with DMBO.

METHODS

A retrospective analysis of prospectively collected data was performed, which included 134 patients with DMBO who underwent palliative BD decompression. Biliary-jejunal drainage was developed to divert bile from the BD directly into the initial loops of the small intestine to prevent duodeno-biliary reflux. IEBJD was carried out using percutaneous transhepatic access. Percutaneous transhepatic biliary drainage (PTBD), endoscopic retrograde biliary stenting (ERBS), and internal-external transpapillary biliary drainage (IETBD) were used for the treatment of study patients. Endpoints of the study were the clinical success of the procedure, the frequency and nature of complications, and the cumulative survival rate.

RESULTS

There were no significant differences in the frequency of minor complications between the study groups. Significant complications occurred in 5 (17.2%) patients in the IEBJD group, in 16 (64.0%) in the ERBS group, in 9 (47.4%) in the IETBD group, and in 12 (17.4%) in the PTBD group. Cholangitis was the most common severe complication. In the IEBJD group, the course of cholangitis was characterized by a delayed onset and shorter duration as compared to other study groups. The cumulative survival rate of patients who underwent IEBJD was 2.6 times higher in comparison to those of the PTBD and IETBD groups and 20% higher in comparison to that of the ERBS group.

CONCLUSION

IEBJD has advantages over other minimally invasive BD decompression techniques and can be recommended for the palliative treatment of patients with DMBO.

Efficacy and Safety of Radiofrequency Ablation Plus Stent Versus Stent-alone Treatments for Malignant Biliary Strictures: A Systematic Review and Meta-analysis

BACKGROUND/AIMS

Malignant biliary strictures (MBS) are very aggressive and cannot be diagnosed in the early stages due to their asymptomatic nature. Stenting the stricture area of the biliary tree is palliative treatment but has poor survival time. Radiofrequency ablation plus stent (RFA+S) have been recently used to improve the survival and stent patency time in patients with MBS. In this systematic review and meta-analysis, we tried to evaluate the efficacy and safety of radiofrequency ablation.

MATERIALS AND METHODS

Study search up to December 2021 was performed in different medical databases such as PubMed, Web of Science, and Cochrane library, etc. We selected eligible studies reporting survival time, stent patency time, and adverse events in patients with MBS. We compare the outcomes of RFA+S and stent-alone treatment groups.

RESULTS

A total of 15 studies (6 randomized controlled trials and 9 observational studies) with 1815 patients were included for meta-analysis of which 701 patients were in RFA+S group and 1114 patients in the stent-alone group. Pooled mean difference of survival time was 2.88 months (95% CI: 1.78-3.97) and pooled mean difference of stent patency time was 2.11 months (95% CI: 0.91-3.30) and clinical success risk ratio was 1.05 (95% CI: 1.01-1.09). Risk ratios for adverse events are given; Bleeding 0.84 (95% CI: 0.34-2.11), abdominal pain 1.06 (95% CI: 0.79-1.40), pancreatitis 0.93 (95% CI: 0.43-2.01), cholangitis 1.07 (95% CI: 0.72-1.59), and stent dysfunction 0.87 (95% CI: 0.70-1.07).

CONCLUSIONS

Radiofrequency ablation is involved in increased survival and stent patency time for MBS patients. With the help of better techniques, adverse events can be limited.

Comparison of 6-mm and 10-mm-diameter, fully-covered, self-expandable metallic stents for distal malignant biliary obstruction

Background and study aims For distal malignant biliary obstruction, self-expandable metallic stents (SEMSs) have a larger inner diameter compared to plastic stents, which prolongs time to recurrent biliary obstruction (TRBO), although stent-related complications are still a problem. This study aimed to compare the outcomes between using 10– and 6-mm-diameter fully-covered SEMS (FCSEMS) for distal malignant biliary obstruction.

Patients and methods This single-center, retrospective study included patients with 10-mm or 6-mm-diameter FCSEMS to treat distal malignant biliary obstruction. Clinical success, stent-related adverse events (AEs), cumulative incidence of RBO, factors involved in stent-related AEs, and factors involved in RBO were evaluated.

Results There were 243 eligible cases between October 2017 and December 2021. The cumulative incidence of RBO did not differ significantly between the 10-mm and 6-mm groups. Stent-related AEs occurred in 31.6 % and 11.4 % of patients between the 10-mm and 6-mm groups, respectively (P < 0.01). Pancreatitis occurred in 10.5 % and 3.6 % (P = 0.04) and cholecystitis occurred in 11.8 % and 3.0 % of patients (P = 0.03) in the 10-mm and 6-mm groups, respectively. In multivariate analysis, the 6-mm stent was extracted as a factor linked to a reduced risk of AEs, but not as a risk factor of RBO.

Conclusions The 6-mm-diameter FCSEMS for distal malignant biliary obstruction is a well-balanced stent with a cumulative incidence of RBO compatible to that of the 10-mm-diameter FCSEMS and fewer stent-related AEs.

Retrospective evaluation of slim fully covered self-expandable metallic stent for unresectable malignant hilar biliary obstruction

BACKGROUND

There have been few reports of covered self-expandable metallic stent (SEMS) placement for malignant hilar-biliary obstruction (MHBO) because of risk of biliary branch obstruction. We studied feasibility and efficacy of 6-mm-diameter, slim, fully covered SEMS (SFCSEMS) in a relatively large cohort.

METHODS

We retrospectively evaluated SFCSEMS in unresectable MHBO from December 2016 to September 2021 in Juntendo University Hospital.

RESULTS

We enrolled consecutive 54 unresectable MHBO (18 bile duct, 11 gallbladder, eight pancreatic, two hepatocellular, and 15 metastatic cancer cases) including Bismuth-type II (n = 11), III (n = 17), and IV (n = 26), and placed two (n = 35) or three (n = 19) SFCSEMS. The technical and clinical success rate was 100% and 92.5%, respectively, with 76.3 min of mean procedure time. Recurrent biliary obstruction (RBO) was observed in 35.2% and the median cumulative time to RBO (TRBO) was 181 days. Other adverse events were 11.1% (four mild-pancreatitis, one segmental-cholangitis, and one cholecystitis). There were no failed cases of stent exchange and second SFCSEMS (n = 6) showed significantly lower RBO (16.7% vs. 81.8%, P = .0364) and longer TRBO (undefined vs 86 days; P = .0617) than plastic stent (n = 11).

CONCLUSIONS

Endoscopic placement of SFCSEMS for unresectable MHBO was effective and feasible with low incidence of segmental cholangitis, and exchange strategy of SFCSEMS was promising.

Covered versus uncovered double bare self-expandable metal stent for palliation of unresectable extrahepatic malignant biliary obstruction: a randomized controlled multicenter trial

BACKGROUND AND AIMS

In a recent randomized controlled trial, a double bare metal stent (DBS) showed better stent patency than single-layer metal stents. However, clear evidence comparing the efficacy of uncovered (UCDBS) and partially covered (PCDBS) DBSs for distal malignant biliary obstruction (MBO) is lacking. Therefore, we compared the clinical outcomes including stent patency of UCDBSs versus PCDBSs.

METHODS

A multicenter, randomized study was performed in patients with distal MBO. The primary endpoint was stent patency. Secondary endpoints were the proportion of patients with patent stents at 6 months, risk factors for stent dysfunction, overall survival, technical and clinical success rates of stent placement, and other adverse events (AEs).

RESULTS

Among 258 included patients, 130 were randomly assigned to the PCDBS group and 128 to the UCDBS group. The mean duration of stent patency of the PCDBS (421.2 days; 95% confidence interval [CI], 346.7-495.7) was longer than that of the UCDBS (377.4 days; 95% CI, 299.7-455.0), although total stent dysfunction and stent dysfunction within 6 months were not different between groups. Multivariate analysis indicated that chemotherapy after stent placement was a significant factor for overall survival (hazard ratio, .570; 95% CI, .408-.796) and had a marginal impact on stent patency (hazard ratio, 1.569; 95% CI, .923-2.667). There were no remarkable differences in AEs, including pancreatitis, cholecystitis, and stent migration, between the 2 groups.

CONCLUSIONS

The use of PCDBSs compared with UCDBSs in patients with distal MBO has unclear benefits regarding stent patency and overall survival, although PCDBSs have a lower rate of tumor ingrowth. (Clinical trial registration number: NCT02937246.).

The usefulness of endobiliary radiofrequency ablation before metal stent placement in unresectable malignant hilar obstruction

BACKGROUND AND AIM

EB-RFA with self-expandable metal stent (SEMS) may improve the stent patency and patient survival in malignant extrahepatic biliary obstruction. However, there are few studies on the role of EB-RFA for malignant hilar obstruction (MHO). This study aimed to assess the feasibility, efficacy, and safety of EB-RFA for MHO.

METHODS

We retrospectively compared the stent patency and survival among 79 consecutive patients with MHO who underwent bilateral uncovered SEMS placement without and with EB-RFA between April 2016 and January 2020.

RESULTS

Fifty-one patients (64.6%) underwent SEMS placement alone (stent alone group), whereas 28 (35.4%) underwent SEMS placement after EB-RFA (RFA-stent group). All procedures were successful (100%). During follow-up, stent occlusion occurred in 59 patients (74.7%), of which 40 (78.4%) and 19 (67.9%) were in the stent alone and RFA-stent groups, respectively. There was no difference in stent patency (192 ± 39.2 days vs 140 ± 53.7 days, P = 0.41) and survival (311 ± 24.7 days vs 311 ± 46.9 days, P = 0.73) between the stent alone and RFA-stent groups. Multivariate cox analysis showed a hazard ratio (HR) of 2.892 (1.579-5.294, P = 0.001) for stent occlusion in patients who did not receive chemotherapy. EB-RFA had no significant effect on stent occlusion (HR, 1.150, 0.644-2.053, P = 0.636).

CONCLUSIONS

SEMS placement after EB-RFA in MHO was not associated with improvement in the stent patency or patient survival. Further prospective randomized studies are necessary to establish the effectiveness of EB-RFA with stents in MHO.

Efficacy and safety of percutaneous endobilliary radiofrequency ablation with a novel temperature-controlled catheter in malignant biliary strictures

Purpose

The purpose of this study is to evaluate the efficacy and safety of temperature-controlled endobilliary radio-frequency ablation (EB-RFA) followed by metal stent placement for nonresectable malignant biliary strictures.

Material and methods

From May 2017 to March 2021, 18 patients with malignant biliary obstruction who had undergone percutaneous EB-RFA and stent placement (n = 9) or stent placement only (n = 9) were included in this retrospective study. Outcomes were stent patency, technical and clinical success, overall survival, and 30-day complication rate. Kaplan-Meier and Cox regression analyses were performed to examine the relationship of EB-RFA with stent patency and overall survival.

Results

The clinical and technical success rate for each group was 100%. The median stent patency was 128 days (95% CI: 122.2-133.8) in the EB-RFA group and 86 days (95% CI: 1.2-170.7) in the control group. It was significantly longer in the study group (p = 0.012). The mean overall survival was 267.7 ± 68.5 days (95% CI: 133.3-402.2) in the study group and 239.6 ± 33.9 days (95% CI: 173.1-306.2) in the control group. Log-rank test showed there was not a statistically significant difference in overall survival rates (p = 0.302). There were no major complications and no statistically significant difference in cholangitis rates (p = 0.620).

Conclusions

Percutaneous temperature-controlled EB-RFA combined with biliary stent placement for malignant biliary obstruction can be safe and feasible, and effectively increase stent patency.

Comparison of outcomes between secondary fully covered and uncovered self-expandable metal stents in the treatment of recurrent biliary obstruction of pancreatic cancer

BACKGROUND

The overall survival (OS) of pancreatic cancer (PC) has been prolonged by advances in chemotherapy, and the number of cases of recurrent biliary obstruction (RBO) after self-expandable metal stent (SEMS) placement is expected to increase. We herein compared outcomes between secondary fully covered SEMS (FC) and uncovered SEMS (UC) for RBO of PC with FC placed as the 1st SEMS.

METHODS

Between May 2010 and March 2021, 62 PC patients who underwent SEMS exchange to FC (n = 34) or UC (n = 28) for RBO were retrospectively analyzed. Patient characteristics, OS, time to RBO (TRBO), and stent-related adverse events were compared between the FC and UC groups. Cox's proportional hazard model was used to identify risk factors for RBO with the 2nd SEMS.

RESULTS

There was a significant difference between the FC and UC groups only in the 2nd SEMS diameter. Median OS and TRBO were 195 and 238 days in FC patients and 306 and 455 days in UC patients, respectively, with no significant differences between the two groups. No significant differences were observed in the stent-related adverse event rate. In multivariate analyses, only the 2nd SEMS diameter was significant (P = 0.009). Median TRBO were 455, 238, and 103 days in 10-mm UC, 10-mm FC, and 8-mm UC patients, with 10-mm UC patients having significantly longer TRBO than 10-mm FC and 8-mm UC patients (P = 0.020 and 0.001).

CONCLUSION

SEMS exchange to 10-mm UC may be appropriate for RBO of PC with FC as the 1st SEMS.

Safety and Efficacy of a Large-Bore Biliary Metallic Stent for Malignant Biliary Obstruction

Self-expandable metallic stents (SEMSs) are typically inserted in patients with unresectable malignant biliary obstruction. However, SEMSs are susceptible to occlusion. To overcome this issue, we developed a large-bore, dumbbell-shaped, fully covered SEMS (FCSEMS-L) and compared its efficacy and safety with those of a conventional FCSEMS (FCSEMS-C) in patients with malignant biliary obstruction. Methods: Patients with unresectable distal malignant biliary obstruction were retrospectively enrolled between January 2011 and February 2021. All patients underwent endoscopic insertion of FCSEMSs. Recurrent biliary obstruction (RBO), patient survival time, complications, and prognosis were analyzed. Results: RBO occurred in 31 patients (35.6%) who received an FCSEMS-L, and in 34 (45.9%) who received an FCSEMS-C. Stent occlusion occurred in 19 patients (21.8%) who received an FCSEMS-L, and in 22 (29.7%) who received an FCSEMS-C. Stent migration occurred in 12 patients (13.8%) with an FCSEMS-L and 12 (16.2%) with an FCSEMS-C. The median time to RBO (TRBO) was 301 days with an FCSEMS-L and 203 days with an FCSEMS-C. The median survival time was 479 days with an FCSEMS-L and 523 days with an FCSEMS-C. The TRBO and patient survival time did not significantly differ between the two groups. Conclusions: There were no significant differences in efficacy and complication rates between the fully covered large bore SEMSs and conventional fully covered SEMSs.

Long Slimmer Metal Stent Is Feasible and Effective for Endoscopic Dual Stent-by-Stent Placement in Malignant Hilar Biliary Stricture

BACKGROUND

Bilateral endoscopic biliary stenting remains technically challenging, which limits its wider clinical application.

AIMS

We have developed a novel long (10-12 cm) and slimmer (6 mm) self-expanded metal stent. The aim of this study was to evaluate the feasibility, efficacy, and safety of the new metal stent for palliative treatment of malignant hilar biliary strictures (MHBS).

METHODS

This retrospective study of prospectively collected data included 45 patients with unresectable malignant hilar biliary strictures of Bismuth type II or higher. A pair of long slimmer metal stents were sequentially placed into the intrahepatic duct using the stent-by-stent mode. The success rate and short- and long-term clinical outcomes were observed.

RESULTS

The technical success rate was 100%, with a mean procedure time of 43.7 ± 11.5 min. The clinical success was achieved in 44 patients (97.8%). Early adverse events included mild acute pancreatitis (n = 2) and cholangitis (n = 3). Later cholangitis occurred in 14 of the 45 patients due to stent occlusions. The median stent patency was 260 days (95% CI 228.3-291.7). Stent malfunctions occurred in 23 of the 45 patients, and 15 of them received bilateral endoscopic plastic stents placements. The technical success for the re-intervention was 100% with the mean procedure time of 24.3 ± 4.5 min. The median overall survival of the whole group was 229 days (95% CI 171.2-286.8).

CONCLUSIONS

The long slimmer metal stent for bilateral endoscopic stent-by-stent placement proved to be safe, feasible, and effective for MHBS and facilitates endoscopic re-intervention as well.

Indian College of Radiology and Imaging Evidence-Based Guidelines for Percutaneous Image-Guided Biliary Procedures

Percutaneous biliary interventions are among the commonly performed nonvascular radiological interventions. Most common of these interventions is the percutaneous transhepatic biliary drainage for malignant biliary obstruction. Other biliary procedures performed include percutaneous cholecystostomy, biliary stenting, drainage for bile leaks, and various procedures like balloon dilatation, stenting, and large-bore catheter drainage for bilioenteric or post-transplant anastomotic strictures. Although these procedures are being performed for ages, no standard guidelines have been formulated. This article attempts at preparing guidelines for performing various percutaneous image-guided biliary procedures along with discussion on the published evidence in this field.

Percutaneous endobiliary ablation of malignant biliary strictures with a novel temperature-controlled radiofrequency ablation device

PURPOSE

We aimed to determine the safety and effectiveness of percutaneous endobiliary radiofrequency ablation of malignant biliary obstructions with a temperature-controlled radiofrequency ablation device.

METHODS

In this single center retrospective study, a total of 62 consecutive patients with malignant biliary obstruction were evaluated. Thirty patients who underwent endobiliary radiofrequency ablation with metallic stent placement were in the study group and 32 patients who underwent only metallic stenting were in the control group. Outcomes of this study were technical success, complications related to the procedure, stent patency, and overall survival.

RESULTS

All procedures were technically successful in both groups. There was no procedure-related mortality in either group. Procedural complication rates were similar between the groups. Although statistically not significant, the only two major complications (hemobilia requiring endovascular treatment) were in the control group. Median primary stent patency was significantly longer in the study group than in the control group (223 days vs. 158 days; P = 0.016). Median survival rates were also longer in the study group (246 days vs. 198 days; P = 0.004).

CONCLUSION

Percutaneous endobiliary radiofrequency ablation is safe and feasible with this novel radiofrequency ablation device in patients with malignant biliary obstruction. Percutaneous endobiliary radiofrequency ablation has a potential to improve both stent patency and survival.

External-Internal Biliary-Jejunal Drainage in Palliative Treatment of Distal Mechanical Jaundice

Введение. Метод выбора дренирования желчных протоков у пациентов с дистальной злокачественной механической желтухой (ДЗМЖ) остается дискуссионным.Цель. Разработать и внедрить в клиническую практику методику наружно-внутреннего билиарно-еюнального дренирования и сравнить ее результаты с ретроградным эндоскопическим стентированием при паллиативном лечении дистальной механической желтухи.Материалы и методы. В проспективное исследование вошло 54 пациента с ДЗМЖ: 29 пациентам выполнена разработанная методика наружно-внутреннего билиарно-еюнального дренирования (группа НВБЕД); 25 – эндоскопическое ретроградное билиарное стентирование (группа ЭРБС) с использованием непокрытых металлических стентов. НВБЕД проводилась с использованием предложенного дренажа, устанавливаемого посредством чрескожного чреспеченочного доступа, при этом конец дренажа с дистальной группой боковых отверстий размещался в начальных петлях еюнум, проксимальная группа боковых отверстий – в расширенных желчных протоках над стенозом.Точками исследования были клинический успех процедуры, частота и характер осложнений, накопленная выживаемость, накопленное время проходимости стента.Результаты. Клинический успех процедуры достигнут в группе НВБЕД у 82,1% пациентов, в группе ЭРБС – у 84,0% (р>0,05).В группе НВБЕД осложнения возникли у 5 (17,9%) пациентов, в группе ЭРБС – у 16 (64,0%) (р=0,002), в том числе холангит – у 10,3% против 36,0% (р=0,024) и панкреатит у 6,9%, против 36,0% (р=0,023) соответственно.При использовании НВБЕД накопленное выживание составило 252,3 дня (95% ДИ: 207,5–297,1) против 203,3 дня (95% ДИ: 164,5–242,1) в группе ЭРБС (р=0,072). Это мы связываем со снижением частоты холангита в группе НВБЕД. В целом накопленное выживание составило 248,9 дня (95% ДИ: 212,2–285,5) при отсутствии у пациентов эпизодов холангита против 168,8 дня (95% ДИ: 132,3–205,4) при наличии холангита (р=0,005).У пациентов с холангитом накопленное время проходимости стентов составляло 157,1 дня (95% ДИ: 132,1–182,1), при отсутствии холангита – 269,6 дня (95% ДИ: 230,3–309,0), р=0,005. У пациентов с НВБЕД закупорки просвета дренажа не наблюдали.Заключение. Предложенная методика наружно-внутреннего билиарно-еюнального дренирования при паллиативном лечении дистальной механической желтухи предпочтительнее эндоскопического ретроградного билиарного стентирования.

Introduction. The choice of bile duct drainage in patients with distal malignant obstructive jaundice (DMOJ) remains controversial.Purpose. To develop and introduce into clinical practice a technique for external-internal biliary- jejunal drainage and compare its results with retrograde endoscopic stenting in palliative treatment of DMOJ.Materials and methods. The prospective study included 54 patients with DMOJ: 29 patients underwent the developed method of external-internal biliary-jejunal drainage (NVBED group); 25 – endoscopic retrograde biliary stenting (ERPS group) using metal stents. NVBED was carried out using the proposed drainage installed by means of a percutaneous transhepatic approach, while the end of the drainage with the distal group of lateral holes was located in the initial loops of the jejunum, the proximal group of lateral holes – in the dilated bile ducts above the stenosis.The points of the study were the clinical success of the procedure, frequency and nature of complications, accumulated survival rate, accumulated time of stent patency.Results. Clinical success of the procedure was achieved in 82.1% of patients in the NVBED group, and 84.0% of patients in the ERHD group, p>0.05.In the IVBED group, complications occurred in 5 (17.9%) patients, in the ERHD group – in 16 (64.0%) patients, p=0.002, including cholangitis – in 10.3% versus 36.0% (p=0.024) and pancreatitis – in 6.9% versus 36.0% (p=0.023), respectively.When using NVBED, the cumulative survival was 252.3 days (95% CI: 207.5–297.1) versus 203.3 days (95% CI: 164.5–242.1) in the ERBS group (p=0.072). We associate this with the decrease of the incidence of cholangitis in the IVBED group. Thus, the overall cumulative survival was 248.9 days (95% CI: 212.2–285.5) in the absence of cholangitis episodes versus 168.8 days (95% CI: 132.3–205.4) in the presence of cholangitis, p=0.005.In patients with cholangitis, the cumulative time of stent patency was 157.1 days (95% CI: 132.1– 182.1); in the absence of cholangitis – 269.6 days (95% CI: 230.3–309.0, p=0.005. In patients with NVBED, the drainage lumen blockage was not observed.Conclusion. The proposed method of external-internal biliary-jejunal drainage for palliative treatment of distal obstructive jaundice is preferable in comparison with endoscopic retrograde biliary stenting.

[Palliative endoscopy]

Endoscopy is the leading method in the diagnostics of gastrointestinal malignancies. With the increasing incidences of various tumor entities, a palliative treatment situation is already present in many patients despite an increasing number of screening strategies. Palliative endoscopy can make an essential contribution to alleviation of tumor-related symptoms, such as dysphagia, malnutrition, cholestasis, ileus and pain. Various approaches can be offered to safeguard the nutrition, e.g. percutaneous endoscopic gastrostomy (PEG) and percutaneous endoscopic jejunostomy (PEJ), for maintenance of the gastrointestinal passage (stents) and secretion drainage or to drain congested hollow organs. Furthermore, in cases of inaccessibility or impassability of stenoses due to tumors, endosonographically assisted punctures offer the possibility to guarantee new drainage options or continuities by stent placement. In all interventions possible contraindications and complications must be taken into account.

Anticancer Effect of Biodegradable Magnesium on Hepatobiliary Carcinoma: An In Vitro and In Vivo Study

Biliary-stent implantation has become an effective treatment for patients with malignant obstructive jaundice caused by hepatobiliary carcinoma. Stent restenosis due to tumor ingrowth is a common problem. In this study, we assessed a biodegradable form of magnesium (Mg) for its anticancer effect on hepatobiliary carcinoma, compared to the conventional stent material of titanium (Ti). The results showed that a Mg extract inhibited proliferation and induced apoptosis in human cholangiocarcinoma cells, while a Mg plate inhibited cell adhesion and destroyed the cytoskeleton in the process of biodegradation. In animal experiments with H22 tumor-bearing mice, Mg wires implanted in tumors exhibited an inhibitory effect on their growth compared with Ti wires. Fifteen days after implantation of metal wires, the mean tumor volume and weight in the Mg group were significantly smaller than in the Ti group. We observed the dynamic-degradation process of Mg wires in tumors and generation of H₂ gas via soft X-ray photography and scanning electron microscopy. Histopathological analyses showed that apoptosis of tumor cells around Mg wires significantly increased, expression of carbonic anhydrase 9 significantly decreased, and the upstream protein hypoxia-inducible factor 1-alpha also decreased to some extent. Taken together, these results indicated that biodegradable Mg had antitumor properties both in vitro and in vivo, suggesting its potential application as a novel material for biodegradable biliary stents.

Feasibility and Safety of Endoluminal Radiofrequency Ablation as a Rescue Treatment for Bilateral Metal Stent Obstruction Due to Tumor Ingrowth in the Hilum: A Pilot Study

Background. Radiofrequency ablation (RFA) is a palliative method known for its application in the endoscopic treatment of malignant bile duct obstruction. It may be a useful rescue method for metal stent malfunction caused by tumor ingrowth. This study aimed to examine the feasibility and safety of endoluminal RFA for occluded bilateral hilar metal stents due to tumor ingrowth in patients with malignant hilar bile duct obstruction. Methods: From March 2016 to June 2018, 11 patients with unresectable malignant hilar bile duct stricture with occluded bilateral hilar metal stents due to tumor ingrowth were enrolled. Endoluminal RFA was performed through a novel temperature-controlled catheter at a setting of 7 W power for 120 s with a target temperature of 80 °C via endoscopic retrograde cholangiopancreatography (ERCP). The patients’ demographics, clinical outcomes, and adverse events were investigated. Results: The median age was 64 (interquartile range, 54–72) years. All RFA procedures were successful. Clinical success was achieved in eight patients (72.7%). During the follow-up, eight patients (72.7%) showed stent dysfunction, and the median patency after RFA was 50 days (95% confidence interval (CI): 34–not available (NA)). All stent dysfunctions were successfully managed with ERCP. Ten patients died, and the median overall survival was 289 days (95% CI, 107–NA) from RFA to death. There was one case of mild abdominal pain after the procedure without serious adverse events. Conclusions: As a rescue therapy for occluded bilateral hilar metal stents due to tumor ingrowth, endoluminal RFA seemed to be safe and useful in selected patients.

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.

Stent insertion with high-intensity focused ultrasound ablation for malignant biliary obstruction: A protocol of systematic review and meta-analysis

BACKGROUND

This meta-analysis was conducted in order to understand the clinical efficacy of stent insertion with high-intensity focused ultrasound (HIFU) ablation for the treatment of malignant biliary obstruction (MBO).

METHODS

The Pubmed, Embase, and Cochrane Library databases were searched for all relevant studies published through July 2020. The meta-analysis was conducted using RevMan v5.3, with analyzed study endpoints including the rate of stent dysfunction, time to stent dysfunction, stent patency, complication rate, and overall survival (OS).

RESULTS

In total, 35 potentially relevant studies were initially identified, of which 6 were ultimately included in the present meta-analysis. These 6 studies included 429 MBO patients that were treated either only via stenting (n = 221) or via stenting in combination with HIFU ablation (n = 208). Pooled stent dysfunction rates in the stent and stent with HIFU groups were 25.9% and 18.0%, respectively (OR: 1.59; 95% CI: 0.88, 2.84, P = .12). The average time to stent dysfunction was significantly longer in the stent with HIFU group relative to the stent group (MD: -3.15; 95% CI: -3.53, -2.77, P < .0001). Pooled complication rates in the stent and stent with HIFU groups were 17.1% and 19.6%, respectively (OR: 0.88; 95% CI: 0.49, 1.58, P = .67). Stent patency and OS were both significantly longer in the stent with HIFU group relative to the stent group (P < .0001 and.0001, respectively). Funnel plot analyses did not reveal any significant evidence of publication bias linked to the selected study endpoints.

CONCLUSIONS

This meta-analysis found that a combined stenting and HIFU ablation approach can achieve better stent patency and OS in MBO patients relative to stent insertion alone.

Survival Benefit of Intraductal Radiofrequency Ablation for Malignant Biliary Obstruction: A Systematic Review with Meta-Analysis

BACKGROUND/AIMS

Cholangiocarcinoma (CCA) is a rare but aggressive disease with a poor survival. Recent trials have shown improved survival with intraductal radiofrequency ablation (RFA) therapy. We performed a systematic review with meta-analysis to determine the survival benefit of endoscopic RFA for unresectable extrahepatic CCA with malignant biliary obstruction (MBO).

METHODS

A systematic search from 1970 to 2020 was performed in MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials. gov. We selected eligible studies reporting relative risks, hazard ratios (HRs), or odds ratios, adjusted by controlling for confounding factors of survival rate and stent patency duration, among patients with extrahepatic CCA with MBO treated with RFA with stent insertion or stent insertion only.

RESULTS

A total of eight trials (three randomized and five nonrandomized) with a total of 420 patients were included in the metaanalysis. Pooled overall survival analysis favored RFA treatment with stent insertion (HR, 0.47; 95% confidence interval [CI], 0.34- 0.64; I2=47%; p=0.09); however, no significant difference was found in the duration of stent patency between the groups (HR, 0.79; 95% CI, 0.57-1.09; I2=7%; p=0.36).

CONCLUSION

RFA therapy with stent insertion may confer a survival benefit compared with stent insertion only in patients with CCA and MBO.

Iodine-125 Seeds Combined With Biliary Stent Placement Versus Stent Placement Alone For Unresectable Malignant Biliary Obstruction: A Meta-Analysis Of Randomized Controlled Trials

Background and Aims: Malignant biliary obstruction is always caused by tumors which are unresectable so that palliative stent placement is conducted for drainage of bile duct tree. Recently, irradiation stent with 125I seeds has been used to improve the stent patency and survival time of patients. We conducted this meta-analysis to evaluate the therapeutic efficacy and safety of biliary stent placement with 125I seeds compared with stent placement alone in patients with malignant biliary obstruction. Methods: We searched Pubmed, Web of Science, ClinicalTrials.gov, Cochrane Library, Embase and CNKI databases for all relevant studies up to 1 May 2020. Patient survival, stent patency, and adverse events were the primary outcome measured. Also, Review Manager 5.3 and Stata/SE15.0 were used to perform the analysis. Results: Eleven randomized controlled trials with a total of 767 patients were included for meta-analysis. Stent combined with 125I seeds showed lower risk of stent occlusion at 3 month (Odds Ratios(OR) = 0.15; 95%CI: 0.05-0.49, P =0.002), 6 month (OR = 0.18; 95%CI: 0.08-0.44, P = 0.0001), 9 month (OR = 0.10; 95%CI: 0.05-0.20, P < 0.00001) and 1 year (OR = 0.15; 95%CI: 0.07-0.31, P < 0.00001) and better mean survival (MD = 125days; 95% CI 91-159 days; P < 0.00001) compared with stent placement alone. Also, reconstructed Kaplan-Meier data demonstrated improved survival in patients treated with stent plus 125I seeds (hazard ratio(HR)= 1.886; 95% CI: 1.609 to 2.210; P < 0.0001) Moreover, our analysis did not show significant difference between the two groups about the risk of adverse events including abdominal pain, hemobilia, pancreatitis, cholangitis and cholecystitis. Conclusion: 125I seeds combined with stent demonstrated superior stent patency and improved survival time compared to stent alone with acceptable complications.

Utility and Safety of a Novel Fully Covered Metal Stent in Unresectable Distal Malignant Biliary Obstruction

BACKGROUND

Self-expandable metal stents (SEMSs) are widely used in patients with distal malignant biliary obstruction. A SEMS that can avoid occlusion as much as possible is desirable.

AIMS

The aim of this multicenter single-arm prospective study was to assess the clinical effectiveness and safety of a novel fully covered braided SEMS.

METHODS

We enrolled consecutive patients with distal malignant biliary obstruction between February 2016 and November 2017 at ten tertiary-care medical centers.

RESULTS

We included 79 patients with a median age of 76 years; 47 (59.5%) patients were men. The technical and clinical success rate was 98.7% and 93.6%, respectively. Recurrent biliary obstruction occurred in 14 patients (17.9%); stent ingrowth, overgrowth, migration, and other occurred in five (6.4%), four (5.1%), four (5.1%), and one (1.3%) patients, respectively. All reinterventions in patients with recurrent biliary obstruction were successful via the transpapillary approach. Adverse events occurred in 15 patients (19.2%); cholangitis, pancreatitis, and others occurred in ten (12.8%), three (3.8%), and two (2.6%) patients, respectively. The stent patency probability at 6 months was 48.5%. Median time to stent patency was 171 days, median time to recurrent biliary obstruction was 536 days, and median survival time was 195 days.

CONCLUSIONS

We confirmed the utility and safety of a novel fully covered braided SEMS with low axial force and high radial force in patients with malignance biliary obstruction. This novel SEMS is recommended in patients with distal malignant biliary obstruction.

Percutaneous endobiliary radiofrequency ablation and stents in management of hepatocellular carcinoma with bile duct tumor thrombus: Initial single-institution experience

AIM

Hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) is a rare condition, but it can lead to hepatic failure and is associated with poor prognosis. Treatment for HCC with BDTT remains a challenge. This study aimed to retrospectively evaluate the safety and feasibility of percutaneous endobiliary radiofrequency ablation (EB-RFA) and biliary metal stent placement as an alternative treatment for patients with HCC with BDTT.

METHODS

From October 2014 to December 2016, nine patients (all men, mean age 53.2 ± 12.0; range 40-70) who underwent percutaneous EB-RFA and biliary metal stent placement for HCC with BDTT were included. Stent patency, overall survival, technical and clinical success rate and complications were investigated.

RESULTS

Median stent patency from the time of the first EB-RFA was 6.0 months (95% CI, 5.4-6.6 months) and survival from the time of diagnosis was 6.0 months (95% CI, 2.2-9.8 months). Two of 9 patients underwent bilateral EB-RFA and stent placement, one underwent unilateral EB-RFA and stent-in-stent procedure, and one EB-RFA as treatment for biliary metal stent occlusion. One patient who presented with stent occlusion underwent repeat ablations 182 days after the first ablation procedure and 53 days after the re-ablation procedure. Combination therapy was administered to five patients. The technical and clinical success rate were 100% and 89% per patient. After treatment, serum direct bilirubin levels were notably decreased in eight patients. No major complications were observed. Minor complications included one bile duct bleeding, three postoperative abdominal pain and two cholangitis.

CONCLUSION

Percutaneous EB-RFA and biliary metal stent placement might be technically safe and feasible therapeutic options for patients with HCC with BDTT.

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.

Partially Covered Versus Uncovered Self-Expandable Metal Stents: Coating Nor Diameter Affect Clinical Outcomes

INTRODUCTION

Jaundice is a common initial presentation of malignant biliary stricture. In patients with life expectancies that are greater than 3 months, self-expanding metal stents (SEMS) offer a larger diameter stent with longer patency and fewer complications compared to plastic stents. There have been conflicting results in the published literature as to efficacy and safety between the various SEMS types and diameters. We compared stent coating (PCSEMS vs USEMS) and diameter on clinical outcomes regarding management of malignant biliary obstruction.

METHODS

A retrospective cohort study was conducted using a database of consecutive patients who underwent an ERCP with biliary SEMS placement (only 8 and 10 mm) between 2009 and 2017.

RESULTS

In total, 278 patients who had SEMS at ERCP for malignant biliary obstruction were included (213 PCSEMS vs 65 USEMS). The groups were demographically evenly matched. Clinical success rates and patency duration were not statistically significant between PCSEMS and USEMS (98.1% vs 95.5%, P = 0.36, and 302.5 vs 225.5 days, P = 0.72, respectively). Adverse event rates were similar between both PCSEMS and USEMS with regard to overall adverse events. Stent diameter did not have an impact on overall clinical success (98.9% vs 95.3%, P = 0.11) or patency duration (239 days vs 336 days, P = 0.51).

CONCLUSIONS

Our comparison of PCSEMS versus USEMS and 8 mm versus 10 mm showed no difference in clinical efficacy or adverse events between the two SEMS coatings and diameter, illustrating that coating and size do not matter in regard to stent choice, despite prior suggestive data.

Risk Factors for the Development of Stent-Associated Cholangitis Following Endoscopic Biliary Stent Placement

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of 8- and 10-mm diameter fully covered self-expandable metal stents: A multicenter prospective study in patients with distal malignant biliary obstruction

OBJECTIVES

The time to recurrent biliary obstruction (TRBO) of unresectable distal malignant biliary obstruction is generally thought to be longer when a self-expandable metal stent (SEMS) with a thicker inner diameter is used for drainage, but the dependence on the inner diameter using a fully covered SEMS (FCSEMS) is uncertain. The objective of this multicenter prospective study was to compare TRBO and adverse events, such as cholecystitis and pancreatitis, in treatment of patients with unresectable malignant biliary obstruction using 8- and 10-mm diameter FCSEMS.

METHODS

Eighteen tertiary-care centers participated in the study. Patients were allocated to the 8- and 10-mm diameter groups. TRBO, non-inferiority of the 8-mm FCSEMS, overall survival time, frequency and type of adverse events, and non-recurrent biliary obstruction (RBO) rate at the time of death were compared between the two groups.

RESULTS

Median TRBO did not differ significantly between the 8-mm (n = 102) and 10-mm (n = 100) groups (275 vs 293 days, P = 0.971). The hazard ratio of the 8- to 10-mm groups was 0.90 (80% confidence interval, 0.77-1.04; upper limit lower than the acceptable hazard ratio [1.33] of the null hypothesis). Based on these findings, the 8-mm diameter stent was determined to be non-inferior to the 10-mm diameter stent. Survival time, incidence of adverse events and non-RBO rate at the time of death did not differ significantly between the two groups.

CONCLUSIONS

Time to RBO with an 8-mm diameter FCSEMS was non-inferior to that with a 10-mm diameter FCSEMS. This finding is important for development of future SEMS.

Endoscopic radiofrequency biliary ablation treatment: A comprehensive review

Radiofrequency ablation (RFA) functions by delivering thermal energy within tissue, the result of a high-frequency alternating current released from an active electrode, leading to coagulative necrosis and cellular death. Recently, a biliary catheter working on a guidewire has been developed and a number of studies have so far been carried out. The present article provides a comprehensive review of the literature on the results of the use of RFA for the clinical management of patients with unresectable malignant biliary strictures, benign biliary strictures, and residual adenomatous tissue in the bile duct after endoscopic papillectomy. Available data show that biliary RFA treatment is a promising adjuvant therapy in patients with unresectable malignant biliary obstruction. The procedure is safe, well tolerated and improves stent patency and survival, even though more studies are warranted. In patients with residual endobiliary adenomatous tissue after endoscopic papillectomy, a significant rate of neoplasia eradication after a single RFA session has been reported, thus favoring this treatment over surgical intervention. In these patients, as well as in those with benign biliary strictures, dedicated probes with a short electrode able to focus the RF current on the short stenosis are needed to expand RFA treatment for these indications.

Radiofrequency and malignant biliary strictures: An update

Malignant biliary strictures are usually linked to different types of tumors, mainly cholangiocarcinoma, pancreatic and hepatocellular carcinomas. Palliative measures are usually adopted in patients with nonresectable or borderline resectable biliary disease. Stent placement is a well-known and established treatment in patients with unresectable malignancy. Intraductal radiofrequency ablation (RFA) represents a procedure that involves the use of a biliary catheter device, via an endoscopic approach. Indications for biliary RFA described in literature are: Palliative treatment of malignant biliary strictures, avoiding stent occlusion, ablating ingrowth of blocked metal stents, prolonging stent patency, ablating residual adenomatous tissue after endoscopic ampullectomy. In this mini-review we addressed focus on technical success defined as deployment of the RF catheter, virtually succeeded in all patients included in the studies. About efficacy, three main outcome measures have been contemplated: Biliary decompression and stent patency, survival. Existing studies suggest a beneficial effect on survival and stent patency with RFA, but current impression is limited because most of studies have been performed using a retrospective design, on diminutive and dissimilar cohorts of patients.

Evaluation of valve function in antireflux biliary metal stents

Background

To overcome duodenobiliary reflux induced by biliary stents, antireflux valve (ARV) biliary stents have been developed and showed improvement in stent patency. However, negative study results have also been reported because stent patency may be decreased by the malfunction of ARV itself. Given such mixed results, the true efficacy of ARV remains unknown and the mechanism of its dysfunction needs to be clearly elucidated. The aim of this study was to investigate the exact mechanism of ARV dysfunction using in vitro phantom models.

Methods

Two experimental models were designed to evaluate two important environmental factors suspected to cause ARV malfunction, i.e. bile flow and pH. Three types of ARV metal stents from different companies were used for the experiments: a funnel type ARV, a windsock type ARV, and a wine glass-shaped ARV. Ten stents of each type were tested (five stents in the bile flow phantom model, and another five stents in the duodenal pH environmental model). To determine ARV malfunction, ARV-induced flow resistance was measured using a custom-made testing device. All stents from the two models were removed every 2 weeks for 12 weeks after stent insertion and were evaluated on morphological and functional changes of the ARV.

Results

Only ARV of wine glass-shaped ARV was morphologically changed due to silicone bond detachment in the bile flow model. All types of ARV were morphologically changed in the pH model. The morphological changes of ARV influenced the flow resistance. The antegrade pressure gradients were increased over time in the pH model (p < 0.05).

Conclusions

Morphological change of the ARVs may induce dysfunction of ARV metal stents, which is mainly due to duodenal pH environment. In the future, development of new ARV that is not affected by duodenal environmental factors can be expected to improve stent patency.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0878-8) contains supplementary material, which is available to authorized users.

Irradiation stents vs. conventional metal stents for unresectable malignant biliary obstruction: A multicenter trial

BACKGROUND & AIMS

Placement of an irradiation stent has been demonstrated to offer longer patency and survival than an uncovered self-expandable metallic stent (SEMS) in patients with unresectable malignant biliary obstruction (MBO). We aim to further assess the efficacy of an irradiation stent compared to an uncovered SEMS in those patients.

METHODS

We performed a randomized, open-label trial of participants with unresectable MBO at 20 centers in China. A total of 328 participants were allocated in parallel to the irradiation stent group (ISG) or the uncovered SEMS group (USG). Endpoints included stent patency (primary), technical success, relief of jaundice, overall survival, and complications.

RESULTS

The first quartile stent patency time (when 25% of the patients experienced stent restenosis) was 212 days for the ISG and 104 days for the USG. Irradiation stents were significantly associated with a decrease in the rate of stent restenosis (9% vs. 15% at 90 days; 16% vs. 27% at 180 days; 21% vs. 33% at 360 days; p = 0.010). Patients in the ISG obtained longer survival time (median 202 days vs. 140 days; p = 0.020). No significant results were observed in technical success rate (93% vs. 95%; p = 0.499), relief of jaundice (85% vs. 80%; p = 0.308), and the incidence of grade 3 and 4 complications (8.5% vs. 7.9%; p = 0.841).

CONCLUSIONS

Insertion of irradiation stents instead of uncovered SEMS could improve patency and overall survival in patients with unresectable MBO.

LAY SUMMARY

For patients with unresectable malignant biliary obstruction (MBO), placement of a self-expandable metallic stent (SEMS) is a recommended palliative modality to relieve pruritus, cholangitis, pain, and jaundice. However, restenosis is a main pitfall after stent placement. Data from this first multicenter randomized controlled trial showed that insertion of an irradiation stent provided longer patency and better survival than a conventional metal stent. ClinicalTrials.gov ID: NCT02001779.

Radiofrequency ablation combined with biliary stent placement versus stent placement alone for malignant biliary strictures: a systematic review and meta-analysis

BACKGROUND AND AIMS

Unresectable malignant biliary strictures are generally managed by palliative stent placement for drainage of biliary tree. Recently, radiofrequency ablation (RFA) has been used to improve the patency of biliary stents in these patients. Several studies have evaluated the effectiveness of biliary stent placement with RFA on stent patency and patient survival with variable results. We performed this meta-analysis to evaluate the efficacy and safety of biliary stent placement with RFA compared with stent placement alone in patients with malignant biliary strictures.

METHODS

We performed a comprehensive search of electronic databases for all studies comparing RFA with biliary stent placement versus stent placement only. Measured outcomes included patient survival, stent patency, and procedure-related adverse events. An inverse variance method was used to pool data on stent patency into a random-effects model. Cox-regression analysis was used to calculate hazard ratio for survival analysis. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework to interpret our findings.

RESULTS

Nine studies (including 2 abstracts) with a total of 505 patients were included in the meta-analysis. The pooled weighted mean difference in stent patency was 50.6 days (95% confidence interval [CI], 32.83-68.48), favoring patients receiving RFA. Pooled survival analysis of the reconstructed Kaplan-Meier data showed improved survival in patients treated with RFA (hazard ratio, 1.395; 95% CI, 1.145-1.7; P < .001). However, RFA was associated with a higher risk of postprocedural abdominal pain (31% vs 20%, P = .003). Our analysis did not show significant difference between the RFA and stent placement-only groups with regard to the risk of cholangitis, acute cholecystitis, pancreatitis, and hemobilia.

CONCLUSIONS

In the light of this limited data based on observational studies, RFA was found to be safe and was associated with improved stent patency in patients with malignant biliary strictures. In addition, RFA may be associated with improved survival in these patients.

Long-term outcomes of EUS-guided choledochoduodenostomy using a lumen-apposing metal stent for malignant distal biliary obstruction: a prospective multicenter study

BACKGROUND AND AIMS

EUS-guided choledochoduodenostomy (EUS-CDS) using conventional tubular stents has been successfully performed. However, EUS-CDS carries a high risk of bile leakage with attendant adverse events. This study aimed to prospectively evaluate the long-term outcome of EUS-CDS using a dedicated lumen-apposing metal stent (LAMS).

METHODS

Nineteen patients (mean age, 70.6 years; 12 men) with unresectable malignant diseases were treated in 5 tertiary referral centers. EUS-CDS was performed using a fully covered LAMS with a cautery-enhanced delivery system for EUS-CDS.

RESULTS

All stents were successfully deployed without any adverse events. Jaundice improved in 79% of the patients within 7 days and finally in 95%. In 95% of patients the stents remained in good anastomotic position without migration or dislocation during the follow-up period (median, 184 days; range, 12-819). One patient had a fever the day after stent placement. During the follow-up period 5 patients had secondary stent obstruction because of food residue (n = 2), kinking (n = 1), suspected tumor ingrowth (n = 1), and spontaneous dislodgement (n = 1). Five patients developed obstruction in the second portion of the duodenum. The overall adverse event rate was 36.8% (7/19), mostly with mild severity.

CONCLUSIONS

This study revealed that the novel dedicated LAMS used has high technical and clinical success rates for EUS-CDS. The adverse events and patency rates are inferior to the historically reported data of a conventional transpapillary metal stent. Development of a more suitable dedicated LAMS is anticipated.

Percutaneous intraductal radiofrequency ablation in the management of unresectable Bismuth types III and IV hilar cholangiocarcinoma

Purpose

To assess the feasibility and safety of percutaneous intraductal radiofrequency ablation (RFA) for unresectable Bismuth types III and IV hilar cholangiocarcinoma.

Results

Percutaneous intraductal RFA combined with metal stent placement was successful in all patients without any technical problems; the technical success rate was 100%. Chemotherapy was administered to two patients. After treatment, serum direct bilirubin levels were notably decreased. Six patients died during the follow-up period. Median stent patency from the time of the first RFA and survival from the time of diagnosis were 100 days (95% confidence interval (CI), 85–115 days) and 5.3 months (95% CI, 2.5–8.1 months), respectively. No acute pancreatitis, bile duct bleeding and perforation, bile leakage, or other severe complications occurred. Four cases of procedure-related cholangitis, three cases of postoperative abdominal pain, and five cases of asymptomatic transient increase in serum amylase were observed. One patient who presented with stent blockage 252 days' post-procedure underwent repeat ablation.

Materials and Methods

Between September 2013 and May 2015, nine patients with unresectable Bismuth types III and IV hilar cholangiocarcinoma who were treated with percutaneous intraductal RFA combined with metal stent placement after the percutaneous transhepatic cholangial drainage were included in the retrospective analysis. Procedure-related complications, stent patency, and survival after treatment were investigated.

Conclusion

Percutaneous intraductal RFA combined with metal stent placement is a technically safe and feasible therapeutic option for the palliative treatment of unresectable Bismuth types III and IV hilar cholangiocarcinoma. Its long-term efficacy and safety is promising, but needs further study via randomized and prospective trials that include a greater number of patients.

New 14-mm diameter Niti-S biliary uncovered metal stent for unresectable distal biliary malignant obstruction

AIM

To investigate whether an uncovered self-expandable metal stent (UCSEMS) with a large diameter could prevent recurrent biliary obstruction (RBO).

METHODS

Thirty-eight patients with malignant biliary obstruction underwent treatment with an UCSEMS with a 14-mm diameter (Niti-S 14). Retrospectively, we evaluated technical and functional success rate, RBO rate, time to RBO, survival time, and adverse events in these patients.

RESULTS

Stent placement success and functional success were achieved in all patients. Two patients (5.3%) had RBO due to tumor ingrowth or overgrowth. The median time to RBO was 190 (range, 164-215) d. The median survival time was 120 (range, 18-502) d. The 6-mo non-RBO rate was 91%. Other adverse events other than RBO occurred as follows: Acute cholecystitis, post-ERCP pancreatitis, hemobilia, and fever without exacerbation of liver injury, and liver abscess in 4 (10.3%), 3 (7.9%), 2 (5.3%), 1 (2.6%), and 1 (2.6%), respectively. Migration of the stents was not observed.

CONCLUSION

Niti-S 14 is considered to be a preferable metal stent because of a low rate of RBO with no migration.

Interventional radiofrequency ablation: A promising therapeutic modality in the management of malignant biliary and pancreatic duct obstruction

Background: Malignant biliary and/or pancreatic obstruction has often encountered in the advanced stages of periampullary and cholangicarcinomas. HabibTM Radiofrequency (RF) ablation has been successfully used in the management of various cancers of liver and pancreas. Percutaneous HPB probe (EMcision Ltd, London, UK) is a new addition to this class of tools. It is an endoluminal Radiofrequency (RF) catheter which works on the principle of ablation and induces coagulative necrosis to recanalize the obstructed duct. The aim of this study is to address the technical details of canalization, feasibilities and outcomes of percutaneous endo-luminal Radiofrequency (RF) catheter in patients with unresectable malignancy with obstructed bile and pancreatic duct (PD). Material and Method: A total of 134 patients with inoperable malignant obstruction of biliary and PD underwent RF based percutaneous endoluminal RF ablation in a tertiary referral centre between December 15th, 2010 to August 7th, 2015. This device was used in a sequential manner with an intent to recanalize the obstructed. Following the initial catheter drainage of the duct, subsequent percutaneous endobiliary RF ablation, the metallic stent was placed to recanalize the obstructed bile and PD secondary to unresectable malignancy under real-time fluoroscopic guidance. Results: The percutaneous RF based ablation of obstructed bile duct and PD with metallic stent placement was successfully achieved in 130 (97.01%) cases. The three failures were noted in cases of biliary obstruction whilst, one with PD obstruction. The patency restored in 124 and patients, where the procedure was successfully completed and revealed clinical improvement reported. Conclusion: The percutaneous endoluminal RF based ablation of obstructed duct with metallic stent placement appeared to be a safe, effective procedure and may improve survival in patients with advanced stage cancer presenting with biliary and PD obstruction. Considering the above mentioned evidence, this modality may stand ahead of stenting alone. This could be considered as viable modality in management of such patients where very limited treatment options are available.

Palliative Percutaneous Biliary Interventions in Malignant High Bile Duct Obstruction

The optimal palliative intervention for malignant biliary obstruction is internal drainage by placement of a metallic stent. For patients with hilar biliary obstruction or low bile duct obstruction in whom endoscopy is not feasible, a percutaneous transhepatic approach in interventional radiology is preferred. This article reviews the rationale for this approach, periprocedural management, and techniques to optimize stent patency.

Endoscopic Palliation of Pancreatic Cancer

OPINION STATEMENT

Pancreas cancer is a fourth-leading cause of cancer death in the USA and its incidence is rising as the population is aging. The majority of patients present at an advanced stage due to the silent nature of the disease and treatment have focused more on palliation than curative intent. Gastroenterologists have become integral in the multidisciplinary care of these patients with a focus on providing endoscopic palliation of pancreas cancer. The three most common areas that gastroenterologists palliate endoscopically are biliary obstruction, cancer-related pain, and gastric outlet obstruction. To palliate biliary obstruction, the procedure of choice is to perform endoscopic retrograde cholangiopancreatography (ERCP) with biliary stent placement. We tend to place covered self-expandable metal stents (SEMS) due to their longer patency and removability unless the patient has resectable disease. Pancreas cancer pain is a result of tumor infiltration of the celiac plexus and can be severe and poorly responsive to narcotics. To improve pain control, neurolysis of the celiac plexus has been performed for decades. Since 1996, neurolysis of the celiac area has been performed endoscopically by Endoscopic Ultrasound-Guided Celiac Plexus Neurolysis. This has proven to be as safe and effective as traditional non-endoscopic methods and has allowed the patients to decrease their narcotic use and improve their pain control. This should be done early on in the course of the disease to have maximal effect. Gastric outlet obstruction (GOO) occurs in approximately 15-20% of patients with pancreas cancer. Endoscopic palliation of GOO can be performed by placing uncovered metal enteral stents across the obstruction. This procedure has proven to be very effective in patients who have a short life expectancy (less than two to 6 months) while surgical bypass should be considered for patients with longer life expectancies because it offers better long-term symptom relief. This chapter will review the current literature, latest advancements, and optimal techniques for endoscopic palliation of pancreatic cancer.