Covered self-expandable metal stents with an anti-migration system improve patency duration without increased complications compared with uncovered stents for distal biliary obstruction caused by pancreatic carcinoma: a randomized multicenter trial

Efficacy and safety of uncovered self-expandable metal stents for distal malignant biliary obstruction in unresectable non-pancreatic cancer

Objectives

The efficacy of uncovered self-expandable metal stents (UCSEMS) versus fully covered self-expandable metal stents for distal malignant biliary obstruction remains controversial. Additionally, the heterogeneity of the disease conditions has been indicated in previous studies because pancreatic and non-pancreatic cancers have different characteristics in clinical course. Therefore, the etiology of biliary obstruction necessitates investigations stratified by primary disease. This study aimed to evaluate the outcomes of UCSEMS, specifically for non-pancreatic cancer-induced distal malignant biliary obstruction.

Methods

We conducted a single-center retrospective review to evaluate the time to recurrent biliary obstruction and frequency of adverse events (AEs) in patients receiving UCSEMS for unresectable non-pancreatic cancer-induced malignant biliary obstruction.

Results

Overall, 32 patients were enrolled in the study between January 2016 and December 2023. The median time to recurrent biliary obstruction was 140 days. AE rates were low at 3.1% for both pancreatitis and cholecystitis, suggesting a potential benefit of UCSEMS in reducing post-procedural AEs.

Conclusion

UCSEMS may reduce the risk of post-procedural AEs and should be considered in patients at high risk of post-endoscopic retrograde cholangiopancreatography pancreatitis. However, the patency period may be shorter, necessitating future comparative research with fully covered self-expandable metal stents to determine the optimal stent choice.

The anti-migration effect of partially covered self-expandable metal stents for unresectable malignant distal biliary obstruction: A multicenter comparative study

Objectives

Covered self-expandable metal stents are commonly used for unresectable malignant distal biliary obstruction. Partially covered self-expandable metal stents have uncovered sections at both ends; however, their anti-migration effect remains unclear. The objective of this study was to evaluate that effect by comparing such stents with fully covered self-expandable metal stents for patients with unresectable malignant distal biliary obstruction.

Methods

This was a multicenter, retrospective comparative study of partially covered stents with fully covered stents for unresectable malignant distal biliary obstruction. Stent migration, recurrent biliary obstruction, and the time to recurrent biliary obstruction were compared between them.

Results

Thirty-nine patients with partially covered stents were included and compared with 42 patients with fully covered stents. The partially covered group had a significantly lower stent migration rate (3% vs. 36%; p < 0.001). The recurrent biliary obstruction rate was significantly lower in the partially covered group (21% vs. 43%; p = 0.036). The non-recurrent biliary obstruction rate at 6 months was 90% and 68% in the partially and fully covered groups, respectively. The time to recurrent biliary obstruction was significantly longer in the partially covered group (Gray's test, p = 0.016). Only partially covered stent placement was significantly associated with a lower risk of stent migration (subdistribution hazard ratio = 0.077; 95% confidence interval = 0.01-0.60; p = 0.014) in the multivariable analysis.

Conclusions

The anti-migration effect of partially covered self-expandable metal stents was associated with a reduced recurrence of biliary obstruction and prolonged time to such obstruction.

Covered Versus Uncovered Metal Stents for the Drainage of the Malignant Distal Biliary Obstruction With ERCP: A Systematic Review and Meta-Analysis

INTRODUCTION AND AIM

Unresectable malignant distal biliary obstruction is a condition that should be treated with drainage and clearance of the biliary duct. self-expanded metal stents (SEMS) are known to be better and more effective than plastic stents because the patency is longer. The actual evidence is insufficient to recommend if it is better the use of SEMSu over SEMSc or vice versa for the drainage of the malignant distal biliary obstruction during ERCP. We performed a systematic review and meta-analyses to demonstrate if exists superiority between one or other type of SEMS performed by ERCP.

MATERIALS AND METHODS

We conducted a systematic review in different databases, such as PubMed, Cochrane, Medline, and OVID database. A search was made of all studies published up to May 2023.

RESULTS

Seven studies were analyzed. A total of 1070 patients were included. Of the total of patients, 48.9% were male. The cumulative stent patency, the failure rate, the survival probably and the adverse events rate, were similar between SEMSc and SEMSu groups. The stent migration rate was higher in the SEMSc group (RR=2.34 [95% CI: 1.35-4.08]). The tumor overgrowth was higher in the SEMSc group (RR=2.05 [95% CI: 1.13-3.72]). The tumor ingrowth was higher in the SEMSu group (RR=0.25 [95% CI: 0.11-0.61]).

CONCLUSIONS

The conclusions of our study show that there are no differences between the use of uncovered SEMS and covered SEMS for palliative treatment of distal biliopancreatic obstructions, and it has no impact on mortality or patient survival. New functional studies regarding the type of stent cover, radial force or length thereof are required.

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

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

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.

Dosimetric characteristics of self-expandable metallic and plastic stents for transpapillary biliary decompression in external beam radiotherapy

There is little evidence regarding radiation dose perturbation caused by the self-expandable metallic stents (SEMSs) used for transpapillary biliary decompression. We aimed to compare SEMSs with plastic stents (PSs) and clarify their dosimetric characteristics. Fifteen SEMSs (10 braided and 5 lasercut type) and six PSs (diameter: 2.3-3.3 mm) were inserted into a water-equivalent solid phantom. In total, 13 SEMSs had radiopaque markers, whereas the other two did not. Using radiochromic films, the dose difference adjacent to the stents at locations proximal, distal, and arc delivery to the radiation source was evaluated based on comparison to measurement of the dose delivery in phantom without any stent in place. The median values of the dose difference for each stent were used to compare the SEMS and PS groups.Results: The dose difference (median (minimum/maximum)) was as follows: proximal, SEMSs + 2.1% (1.8 / 4.7) / PSs + 5.4% (4.1 / 6.3) (p < 0.001); distal, SEMSs -1.0% (-1.6 /-0.4) / PSs -8.9% (-11.7 / -7.4) (p < 0.001); arc delivery, SEMSs 1.2% (0.9 / 2.3) / PSs 2.2% (1.6 / 3.6) (p = 0.005). These results demonstrated that the dose differences of SEMSs were significantly smaller than those of PSs. On the other hand, the dose difference was large at surface of the radiopaque markers for SEMSs: proximal, 10.3% (7.2 / 20.9); distal, -8.4% (-16.3 / -4.2); arc delivery, 5.5% (4.2 / 9.2). SEMSs for biliary decompression can be safely used in patients undergoing radiotherapy, by focusing on the dose distribution around the stents and by paying attention to local changes in the dose distribution of radiopaque markers.

Secondary uncovered versus fully-covered metal stents for the management of occluded stent in unresectable distal malignant biliary obstruction

INTRODUCTION

Self-expandable metallic stents (SEMS) have been widely placed for unresectable distal malignant biliary obstruction (UDMBO). However, the dysfunction rate is 19-40% and its treatment is controversial. We aimed asses the efficacy and safety of a secondary biliary stents (uncovered (UC) versus fully-covered (FC) stent) for the management of occluded SEMS.

PATIENTS AND METHODS

Between 2015 and June 2023, 41 patients with UDMBO underwent secondary biliary stent placement as "stent-in-stent" (20 FCSEMS and 21 UCSEMS). The primary outcomes were technical and clinical success of SEMS placement. Secondary outcomes included adverse events (AEs), patency and survival. Patients were prospectively followed until death or loss of follow-up.

RESULTS

Technical (100% vs 85.5%) and clinical (100% vs 95.2%) success rates were similar in FCSEMS and UCSEMS groups. The median follow-up period was 510 days (range 290-630). The median duration of stent patency of FCSEMS (220 days, IQR 137.5-442.5) was longer than UCSEMS (150 days, IQR 110-362.5) (P=0.395), although stent dysfunction within 6 months was not different between groups. Multivariate analysis indicated that sex (HR=0.909, 0.852-0.970), antitumor treatment (HR=0.248, 0.032-0.441), stent patency (HR=0.992, 0.986-0.998) and clinical success (HR=0.133, 0.026-0.690) were significant factors for overall survival. There were no remarkable differences in AEs.

CONCLUSIONS

The placement of additional biliary stent using the stent-in-stent method is an effective and safe rescue treatment for patients with UDMBO and occluded stent. In addition, the use of FCSEMS compared UCSEMS has unclear benefits regarding stent patency and overall survival.

TOKYO criteria 2024 for the assessment of clinical outcomes of endoscopic biliary drainage

The consensus-based TOKYO criteria were proposed as a standardized reporting system for endoscopic transpapillary biliary drainage. The primary objective was to address issues arising from the inconsistent reporting of stent outcomes across studies, which has complicated the comparability and interpretation of study results. However, the original TOKYO criteria were not readily applicable to recent modalities of endoscopic biliary drainage such as biliary drainage based on endoscopic ultrasound or device-assisted endoscopy. There are increasing opportunities for managing hilar biliary obstruction and benign biliary strictures through endoscopic drainage. Biliary ablation has been introduced to manage benign and malignant biliary strictures. In addition, the prolonged survival times of cancer patients have increased the importance of evaluating overall outcomes during the period requiring endoscopic biliary drainage rather than solely focusing on the patency of the initial stent. Recognizing these unmet needs, a committee has been established within the Japan Gastroenterological Endoscopy Society to revise the TOKYO criteria for current clinical practice. The revised criteria propose not only common reporting items for endoscopic biliary drainage overall, but also items specific to various conditions and interventions. The term "stent-demanding time" has been defined to encompass the entire duration of endoscopic biliary drainage, during which the overall stent-related outcomes are evaluated. The revised TOKYO criteria 2024 are expected to facilitate the design and reporting of clinical studies, providing a goal-oriented approach to the evaluation of endoscopic biliary drainage.

Feasibility of Double-Deployment Small-Diameter Covered Metallic Stent for Malignant Distal Biliary Obstruction (with Video)

BACKGROUND/OBJECTIVES

Covered self-expandable metallic stents (CSEMS) are commonly used to treat malignant distal biliary obstructions. A 10-mm CSEMS carries the risk of obstructing the pancreatic and cystic duct orifices by adhering to the bile duct; therefore, postoperative pancreatitis and cholecystitis are reported to occur at a certain frequency. We have adopted a new drainage technique for malignant distal biliary obstruction called ''double-slim SEMS stenting" (DSS), where two small-diameter CSEMS are placed side-by-side. We aimed to compare the efficacy and safety of biliary drainage using DSS with those of conventional CSEMS.

METHODS

In total, 50 patients who underwent endoscopic biliary drainage for malignant distal biliary obstructions between April 2019 and March 2022 at Hyogo Medical University Hospital were enrolled. Patients were divided into DSS and Conventional groups, and the technical success rate, clinical success rate, adverse events, success rate for reintervention, recurrent biliary obstruction (RBO) rate, and time to RBO (TRBO) were evaluated.

RESULTS

There were no significant differences in patient characteristics between the DSS (n = 20) and Conventional groups (n = 30). The technical and clinical success rates were 100% in the DSS group. The incidence of adverse events was not significantly different between the two groups (DSS/Conventional: 10.0% [2/20]/20.0% [6/30]) (p = 0.34). No acute cholecystitis was observed in the DSS group. The incidence rates of RBO were 30% (6/20) and 43% (13/30) in the DSS and Conventional groups, respectively (p = 0.92). The median TRBO in the DSS group was 378 days, while the TRBO in the Conventional group was 195 days (p = 0.03), resulting in significantly longer TRBO in the DSS group.

CONCLUSIONS

DSS emerges as a viable and safe approach for biliary drainage in malignant distal biliary obstruction, demonstrating a lower incidence of adverse events and longer TRBO compared to conventional CSEMS.

Surgical Palliation for Advanced Pancreas Cancer

To provide optimal care in pancreatic ductal adenocarcinoma, involvement of palliative medicine and nutritional support is recommended. Advances in endoscopy have resulted in robust options for biliary and gastrointestinal stenting for relief of obstruction. Notwithstanding, surgical hepaticojejunostomy and gastrojejunostomy remain incontrovertible considerations for biliary obstruction and gastric outlet obstruction, respectively. For PDAC-associated pain, opioid therapy continues to be the mainstay. However, refractory pain may be treated with interventional procedures such as celiac or splanchnic nerve blocks or neurolysis. In patients with PDAC, enteral nutrition can be further complicated by exocrine pancreatic insufficiency, which should be treated with oral pancreatic enzyme supplementation.

Endoscopic Ultrasound-Guided vs Endoscopic Retrograde Cholangiopancreatography-Guided Biliary Drainage as Primary Approach to Malignant Distal Biliary Obstruction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Endoscopic ultrasound-guided biliary drainage (EUS-BD) is an alternative to endoscopic retrograde cholangiopancreatography (ERCP)-guided transpapillary drainage in malignant distal biliary obstruction (MDBO). This meta-analysis of randomized controlled trials (RCTs) aims to compare the outcomes of these 2 approaches.

METHODS

Electronic databases from January 2005 through December 2023 were searched for RCTs comparing outcomes of EUS-BD and ERCP for treating MDBO. Pooled proportions, risk ratio (RR), and odds ratio were calculated using random-effects models.

RESULTS

Five RCTs comprising 519 patients were included in the final analysis. The pooled RR for overall technical success with EUS-BD compared with ERCP was 1.05 (95% confidence interval [CI] = 0.96-1.16, P = 0.246, I2 = 61%) and for clinical success was 0.99 (95% CI = 0.95-1.04, P = 0.850, I2 = 0%). The pooled rate of procedure-related pancreatitis was 7.20% (95% CI = 3.60-13.80, I2 = 34%) in the ERCP group compared with zero in the EUS-BD group. The pooled RR for stent dysfunction with EUS-BD compared with ERCP was 0.48 (95% CI = 0.28-0.83, P = 0.008, I2 = 7%). The weighted mean procedure time was 13.43 (SD = 10.12) minutes for EUS-BD compared with 21.06 (SD = 6.64) minutes for ERCP. The mean stent patency was 194.11 (SD = 52.12) days in the EUS-BD group and 187 (SD = 60.70) days in the ERCP group.

DISCUSSION

EUS-BD is an efficient and safe alternative to ERCP in MDBO. An almost nonexistent risk of procedure-related pancreatitis, lower procedure time, and ease of use make this an attractive primary approach to biliary decompression in centers with expertise.

Risk factors and treatment strategies for cholecystitis after metallic stent placement for malignant biliary obstruction: a multicenter retrospective study

BACKGROUND AND AIMS

Cholecystitis can occur after self-expandable metallic stent (SEMS) placement for malignant biliary obstruction (MBO), but the best treatment option for cholecystitis has not been determined. Here, we aimed to identify the risk factors of cholecystitis after SEMS placement and determine the best treatment option.

METHODS

Incidence, treatments, and predictive factors of cholecystitis were retrospectively evaluated in 1084 patients with distal MBO (DMBO) and 353 patients with hilar MBO (HMBO) who underwent SEMS placement at 12 institutions from January 2012 to March 2021.

RESULTS

Cholecystitis occurred in 7.5% of patients with DMBO and 5.9% of patients with HMBO. The recurrence rate was significantly lower (P = .043) and the recurrence-free period significantly longer (P = .039) in endoscopic procedures than in percutaneous procedures for cholecystitis treatment. EUS-guided gallbladder drainage (EUS-GBD) was better in terms of technical success, procedure time, and recurrence-free period than endoscopic transpapillary gallbladder drainage. Obstruction across the cystic duct orifice by tumor (P = .015) and by stent (P = .037) were independent risk factors for cholecystitis in DMBO. Cases with multiple SEMS placements (odds ratio [OR], 11; 95% confidence interval [CI], 0.68-190; P = .091) and with gallbladder stones (OR, 2.3; 95% CI ,0.92-5.6; P = .075) had a higher risk for cholecystitis in HMBO.

CONCLUSIONS

The incidences of cholecystitis after SEMS placement for DMBO and HMBO were similar. EUS-GBD is the optimal treatment option for patients with cholecystitis after SEMS placement for MBO.

Braided-type stent versus laser-cut-type stent for patients with unresectable distal malignant biliary obstruction: a randomized controlled trial

BACKGROUND AND AIMS

Fully covered self-expandable metallic stents (SEMSs) are laser-cut (L) or braided (B); however, it remains unclear which approach is more effective for distal malignant biliary obstruction (DMBO). This study compared the clinical outcomes of using L-type and B-type stents because we believe that recurrent biliary obstruction (RBO) is less likely to occur with L-type stents.

METHODS

Patients diagnosed with unresectable DMBO were randomly assigned to groups L and B in a stratified block fashion, and outcomes were compared. The primary outcome was the rate of RBO within 1 year; secondary outcomes were adverse events, clinical success rate, time to RBO (TRBO), and overall survival.

RESULTS

Of the 60 enrolled participants, 56 (group L, n = 27; group B, n = 29) were included. The rates of RBO within 1 year were 44.4% and 17.2% in groups L and B, respectively (odds ratio, 2.57; 95% confidence interval [CI], 1.045-6.353). Early adverse events, which improved with conservative treatment, included pancreatitis (n = 4) in group L and pancreatitis (n = 3) and cholecystitis (n = 1) in group B (P = .913). The median TRBO (220 days [95% CI, 56-272] vs 418 days [95% CI, 232-454]) was significantly longer in group B than in group L (log-rank test, P = .0118). The median overall survival (group L, 158 days; group B, 204 days) after stenting was not significantly different between groups (P = .8544).

CONCLUSIONS

In the setting of DMBO, B-type stents are associated with less recurrent obstruction than L-type stents, although there was no difference in safety. (UMIN Clinical Trials Registry number: UMIN000027239.).

A novel fully covered metal stent for unresectable malignant distal biliary obstruction: results of a multicenter prospective study

BACKGROUND/AIMS

Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO.

METHODS

This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events.

RESULTS

A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration.

CONCLUSIONS

The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration.

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.).

Stent Insertion for Inoperable Hilar Cholangiocarcinoma: Comparison Between Unilateral Radioactive Stent and Bilateral Normal Stent

OBJECTIVE

To comparatively analyze the clinical efficacy and safety of unilateral radioactive stent (RS) insertion versus bilateral normal stent (NS) insertion in patients with inoperable hilar cholangiocarcinoma (HC).

PATIENTS AND METHODS

Patients with inoperable HC were treated in our hospital from January 2016 to December 2020. The treatment approach included the insertion of either unilateral RS or bilateral NS, evaluating the efficacy and safety of therapy in 2 distinct groups.

RESULTS

A total of 58 individuals experienced the insertion of a unilateral RS, whereas 57 patients underwent the insertion of bilateral NS. No statistically significant difference between the unilateral RS and bilateral NS groups was seen in the technical success rates (98.3% vs 94.7%, P = 0.598) and clinical success rates (98.2% vs 100%, P = 0.514). While there is no statistically significant difference in the rates of stent restenosis (19.3% vs 9.3%, P = 0.132) between the two groups, the unilateral RS group demonstrated substantially longer stent patency (202 vs 119 d, P = 0.016) and overall survival (229 vs 122 d, P = 0.004) compared with the bilateral NS group. Moreover, 8 patients (14.0%) in the unilateral RS group and 14 patients (25.9%) in the bilateral NS group had postoperative complications with no significant difference ( P = 0.116).

CONCLUSION

When inserting stents for inoperable HC, both unilateral RS and bilateral NS insertion procedures have demonstrated favorable therapeutic efficacy. Nevertheless, inserting a unilateral RS provided a longer duration of stent patency and overall survival than implantation of bilateral NS.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Comparison Between Plastic and Metallic Biliary Stent Placement for Preoperative Patients with Pancreatic Head Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Optimal preoperative biliary drainage for patients with pancreatic cancer before pancreatoduodenectomy remains unclear. This study aimed to investigate the comparison of efficacy and safety between a metallic stent (MS) and a plastic stent (PS).

METHODS

Comparative studies on the use of MS and PS for pancreatic cancer before pancreatoduodenectomy were systematically searched using the MEDLINE and Web of Science databases. Pre- and postoperative data also were extracted. Random-effects meta-analyses were performed to compare post-endoscopic retrograde cholangiopancreatography (ERCP) complications as well as intra- and postoperative outcomes between the two arms of the study, and pooled odds ratios (ORs) or mean differences (MDs) were calculated with 95 percent confidence intervals (CIs).

RESULTS

The study analyzed 12 studies involving 683 patients. Insertion of MS was associated with a lower incidence of re-intervention (OR, 0.06; 95% CI 0.03-0.15; P < 0.001), increased post-ERCP adverse events (OR, 2.22; 95% CI 1.13-4.36; P = 0.02), and similar operation time (MD, 18.0 min; 95% CI -29.1 to 65.6 min; P = 0.46), amount of blood loss (MD, 43.0 ml; 95% CI -207.1 to 288.2 ml; P = 0.73), and surgical complication rate (OR, 0.78; 95% CI 0.53-1.15; P = 0.21). The cumulative stent patency rate after 3 months was higher in the MS group than in the PS group (70-100 % vs 30.0-45.0 %).

CONCLUSION

For biliary drainage in patients with pancreatic cancer during this era of multidisciplinary treatment, MS use might be the first choice because MS provides a more durable biliary drainage and a similar risk of postoperative outcomes compared with PS.

Adverse events of self-expandable metal stent placement for malignant distal biliary obstruction: a large multicenter study

BACKGROUND AND AIMS

Endoscopic placement of self-expandable metal stents (SEMSs) for malignant distal biliary obstruction (MDBO) may be accompanied by several types of adverse events. The present study analyzed the adverse events occurring after SEMS placement for MDBO.

METHODS

The present study retrospectively investigated the incidence and types of adverse events in patients who underwent SEMS placement for MDBO between April 2018 and March 2021 at 26 hospitals. Risk factors for acute pancreatitis, cholecystitis, and recurrent biliary obstruction (RBO) were evaluated by univariate and multivariate analyses.

RESULTS

Of the 1425 patients implanted with SEMSs for MDBO, 228 (16.0%) and 393 (27.6%) experienced early adverse events and RBO, respectively. Pancreatic duct without tumor involvement (P = .023), intact papilla (P = .025), and SEMS placement across the papilla (P = .037) were independent risk factors for acute pancreatitis. Tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis (P < .001). Use of fully and partially covered SEMSs was an independent risk factor for food impaction and/or sludge. Use of fully covered SEMSs was an independent risk factor for stent migration. Use of uncovered SEMSs and laser-cut SEMSs was an independent risk factor for tumor ingrowth.

CONCLUSIONS

Pancreatic duct without tumor involvement, intact papilla, and SEMS placement across the papilla were independent risk factors for acute pancreatitis, and tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis. The risk factors for food impaction and/or sludge, stent migration, and tumor ingrowth differed among types of SEMSs.

Risk factors for early and late cholecystitis after covered metal stent placement for distal biliary obstruction

BACKGROUND

Cholecystitis is a major adverse event after self-expandable metallic stent placement for distal biliary obstruction (DBO). Covered self-expandable metallic stent (CSEMS) is being increasingly used, but few studies have investigated risk factors for cholecystitis limited to CSEMS. The present study aimed to identify risk factors for cholecystitis after CSEMS.

METHODS

Patients who underwent initial CSEMS placement for DBO between November 2014 and September 2021 were enrolled and followed-up until death, recurrent biliary obstruction, cholecystitis, or until March 2022. Cholecystitis within 30 days of CSEMS was defined as early cholecystitis and after 30 days as late cholecystitis.

RESULTS

Cholecystitis occurred in 51 of 339 patients (15%) after CSEMS. Forty-one patients (80.4%) had early cholecystitis, and 10 (19.6%) had late cholecystitis. Multivariate logistic regression analysis revealed that the maximum diameter of the common bile duct (CBD) (per 1 mm increase) (odds ratio [OR]: 0.87; 95% confidence interval [CI]: 0.76-1.00; p = .044), gallbladder stones (OR: 3.63; 95% CI: 1.62-8.10; p = .002), and tumor involvement in the cystic duct (CD) (OR: 4.87; 95% CI: 2.16-11.00; p < .001) were significant independent risk factors associated with early cholecystitis. No significant risk factors were identified for late cholecystitis.

CONCLUSIONS

A smaller CBD diameter, gallbladder stones, and tumor involvement in the CD were identified as risk factors for early cholecystitis development after CSEMS.

Uncovered versus fully covered self-expandable metal stents for the management of distal malignant biliary obstruction

BACKGROUND AND AIM

Self-expandable metal stents (SEMSs) are widely used for palliation of distal malignant biliary obstruction (dMBO). However, previous studies comparing the outcomes between uncovered SEMSs (UCSEMSs) and fully covered SEMSs (FCSEMSs) report conflicting results. This large cohort study aimed to compare the clinical outcomes between UCSEMSs and FCSEMSs for dMBO.

METHODS

A retrospective cohort study was performed in patients with dMBO who underwent either UCSEMS or FCSEMS placement between May 2017 and May 2021. Primary outcomes were rates of clinical success, adverse events (AEs), and unplanned endoscopic reintervention. Secondary outcomes were types of AEs, intervention-free stent patency, and management and outcomes of stent occlusion.

RESULTS

The cohort included 454 patients (364 in the UCSEMS group and 90 in the FCSEMS group). Median follow-up duration was 9.6 months and was similar between the 2 groups. Use of UCSEMSs and FCSEMSs had comparable clinical success (P = .250). However, use of UCSEMSs had significantly higher rates of AEs (33.5% vs 21.1%; P = .023) and unplanned endoscopic reintervention (27.0% vs 11.1%; P = .002). UCSEMSs had a higher rate of stent occlusion (26.9% vs 8.9%; P < .001) and shorter median time to stent occlusion (4.4 months vs 10.7 months; P = .002). Stent reintervention-free survival was higher in the FCSEMS group. FCSEMSs had a significantly higher rate of stent migration (7.8% vs 1.1%; P < .001), but patients in the FCSEMS group had similar rates of cholecystitis (.3% vs 1.1%; P = .872) and post-ERCP pancreatitis (6.3% vs 6.6%; P = .90). When UCSEMSs did occlude, placement of a coaxial plastic stent had a higher rate of stent reocclusion compared with coaxial SEMS placement (46.7% vs 19.7%; P = .007).

CONCLUSION

FCSEMSs should be considered for the palliation of dMBO because of lower rates of AEs, longer patency rates, and lower rates of unplanned endoscopic intervention.

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

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

EUS-Guided Choledocho-duodenostomy Using Lumen Apposing Stent Versus ERCP With Covered Metallic Stents in Patients With Unresectable Malignant Distal Biliary Obstruction: A Multicenter Randomized Controlled Trial (DRA-MBO Trial)

BACKGROUND & AIMS

Several studies have compared primary endoscopic ultrasound (EUS)-guided biliary drainage to endoscopic retrograde cholangiopancreatography (ERCP) with insertion of metal stents in unresectable malignant distal biliary obstruction (MDBO) and the results were conflicting. The aim of the current study was to compare the outcomes of the procedures in a large-scale study.

METHODS

This was a multicenter international randomized controlled study. Consecutive patients admitted for obstructive jaundice due to unresectable MDBO were recruited. Patients were randomly allocated to receive EUS-guided choledocho-duodenostomy (ECDS) or ERCP for drainage. The primary outcome was the 1-year stent patency rate. Other outcomes included technical success, clinical success, adverse events, time to stent dysfunction, reintervention rates, and overall survival.

RESULTS

Between January 2017 and February 2021, 155 patients were recruited (ECDS 79, ERCP 76). There were no significant differences in 1-year stent patency rates (ECDS 91.1% vs ERCP 88.1%, P = .52). The ECDS group had significantly higher technical success (ECDS 96.2% vs ERCP 76.3%, P < .001), whereas clinical success was similar (ECDS 93.7% vs ERCP 90.8%, P = .559). The median (interquartile range) procedural time was significantly shorter in the ECDS group (ECDS 10 [5.75-18] vs ERCP 25 [14-40] minutes, P < .001). The rate of 30-day adverse events (P = 1) and 30-day mortality (P = .53) were similar.

CONCLUSION

Both procedures could be options for primary biliary drainage in unresectable MDBO. ECDS was associated with higher technical success and shorter procedural time then ERCP. Primary ECDS may be preferred when difficult ERCPs are anticipated. This study was registered to Clinicaltrials.gov NCT03000855.

Efficacy and safety of covered versus uncovered self‑expandable metal stents for the palliative treatment of malignant distal biliary stricture: A long‑term retrospective study

Both covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (USEMSs) have been tried in the palliation of malignant distal biliary strictures by means of endoscopic retrograde cholangiopancreatography (ERCP); however, the comparison of efficacy and safety between them remains contested. To the best of our knowledge, no similar studies have assessed this in the Chinese population. In the present study, the clinical and endoscopic data of 238 patients (CSEMSs, n=55; USEMSs, n=183) with malignant distal biliary strictures from 2014 to 2019 were collected. The efficacy indicated by mean stent patency, stent patency rate, mean patient survival time and survival rate, and the safety indicated by adverse events after CSEMS or USEMS placement were retrospectively analyzed and compared. The mean stent patency time was significantly longer in the CSEMSs group than that in the USEMSs group (262.8±195.3 days vs. 169.5±155.7 days, P=0.002). The mean patient survival time was significantly longer in the CSEMSs group than that in the USEMSs group (273.9±197.6 days vs. 184.9±167.6 days, P=0.003). The stent patency rate and patient survival rate were significantly higher in the CSEMSs group than those in the USEMSs group at 6 and 12 months, but not at 1 and 3 months. There was no significant difference in stent dysfunction and adverse events between the two groups, although post-ERCP pancreatitis (PEP) occurred more frequently in the CSEMSs group than in the USEMSs group (18.1% vs. 8.8%, P=0.049). In conclusion, CSEMSs were better than USEMSs for malignant distal biliary strictures in terms of stent patency time and patient survival time as well as stent patency rate and patient survival rate in the long term (>6 months). Adverse events in the two groups occurred at a similar rate, although the incidence of PEP was higher in the CSEMSs group.

Efficacy of Fully Covered Self-Expandable Metal Stents for Distal Biliary Obstruction Caused by Pancreatic Ductal Adenocarcinoma: Primary Metal Stent vs. Metal Stent following Plastic Stent

Fully covered self-expandable metallic stents (FCSEMSs) are inserted in patients with unresectable pancreatic ductal adenocarcinoma (PDAC) to resolve malignant distal bile duct obstructions. Some patients receive FCSEMSs during primary endoscopic retrograde cholangiopancreatography (ERCP), and others receive FCSEMSs during a later session, after the placement of a plastic stent. We aimed to evaluate the efficacy of FCSEMSs for primary use or following plastic stent placement. A total of 159 patients with pancreatic adenocarcinoma (m:f, 102:57) who had achieved clinical success underwent ERCP with the placement of FCSEMSs for palliation of obstructive jaundice. One-hundred and three patients had received FCSEMSs in a first ERCP, and 56 had received FCSEMSs after prior plastic stenting. Twenty-two patients in the primary metal stent group and 18 in the prior plastic stent group had recurrent biliary obstruction (RBO). The RBO rates and self-expandable metal stent patency duration did not differ between the two groups. An FCSEMS longer than 6 cm was identified as a risk factor for RBO in patients with PDAC. Thus, choosing an appropriate FCSEMS length is an important factor in preventing FCSEMS dysfunction in patients with PDAC with malignant distal bile-duct obstruction.

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.

Re-intervention with 10-mm vs 12-mm covered self-expandable metallic stent for recurrent unresectable distal biliary obstruction in patients with previous stent implantation

BACKGROUND

Treatment for unresectable distal malignant biliary obstruction (DMBO) involves placing a 10-mm covered self-expandable metallic stent (CSEMS). In recurrent biliary obstruction (RBO), replacement of the CSEMS is recommended; however, the appropriate stent type remains unknown. We speculated that large-bore CSEMSs would provide longer patency. We compared the efficacy of 10-mm and 12-mm CSEMS in patients with RBO.

METHODS

We retrospectively retrieved data on patients who underwent CSEMS replacement from the endoscopic database. We investigated the time to RBO (TRBO) after CSEMS replacement. The hazard ratio (HR) for the the second TRBO was estimated using the Cox proportional hazard model. The estimated median second TRBO was determined using the Kaplan-Meier method.

RESULTS

Among the 493 patients with DMBOs treated with 10-mm CSEMS, 48 and 29 patients underwent re-intervention with 10-mm and 12-mm CSEMS, respectively. The use of 12-mm CSEMS was inversely associated with second TRBO (multivariable-adjusted HR, 0.62; 95% CI, 0.39-0.98; P = .042). The estimated median second TRBO was greater with the 12 mm CSEMS than with the 10 mm variety (562 days vs 207 days; P = .019).

CONCLUSION

The second intervention with 12-mm CSEMS was associated with a longer TRBO.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

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.

ACG Clinical Guideline: Diagnosis and Management of Biliary Strictures

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

Classification, risk factors, and management of lumen apposing metal stent dysfunction during follow-up of endoscopic ultrasound-guided choledochoduodenostomy: Multicenter evaluation from the Leuven-Amsterdam-Milan Study Group

OBJECTIVES

Long-term outcomes of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) performed with lumen apposing metal stents (LAMS) have been poorly evaluated in small or retrospective series, leading to an underestimation of LAMS dysfunction.

METHODS

All consecutive EUS-CDS performed in three academic referral centers were included in prospectively maintained databases. Technical/clinical success, adverse events (AEs), and dysfunction during follow-up were retrospectively analyzed. Kaplan-Meier analysis was used to estimate dysfunction-free survival (DFS), with Cox proportional hazard regression to evaluate independent predictors of dysfunction.

RESULTS

Ninety-three patients were included (male 56%; mean age, 70 years [95% confidence interval (CI) 68-72]; pancreatic cancer 81%, metastatic disease 47%). In 67% of procedures, 6 mm LAMS were used. Technical and clinical success were achieved in 97.8% and 93.4% of patients, respectively, with AEs occurring in 9.7% (78% mild/moderate). Dysfunction occurred in 31.8% of patients after a mean of 166 days (95% CI 91-241), with an estimated 6 month and 12 month DFS of 75% and 52%, respectively; mean DFS of 394 (95% CI 307-482) days. Almost all dysfunctions (96%) were successfully managed by endoscopic reintervention. Duodenal invasion (hazard ratio 2.7 [95% CI 1.1-6.8]) was the only independent predictor of dysfunction.

CONCLUSIONS

Endoscopic ultrasound-guided choledochoduodenostomy shows excellent initial efficacy and safety, although stent dysfunctions occurs frequently during long-term follow-up. Almost all stent dysfunctions can be managed successfully by endoscopic reinterventions. We propose a comprehensive classification of the different types of dysfunction that may be encountered and rescue procedures that may be employed under these circumstances. Duodenal invasion seems to increase the risk of developing EUS-CDS dysfunction, potentially representing a relative contraindication for this technique.

A case of delayed pancreatic fistula after covered self-expandable metallic stent deployment for pancreatic head cancer

A 69-year-old man was referred to our hospital with obstructive jaundice. A tumor with poor contrast enhancement was found in the pancreatic head, but there was no evidence of pancreatic atrophy, irregular stenosis, or dilation of the main pancreatic duct. He was diagnosed with borderline resectable pancreatic cancer with distal malignant biliary obstruction. After plastic stent placement, serum bilirubin levels improved, and chemotherapy was started. However, he developed cholangitis; thus, the plastic stent was replaced with a covered self-expandable metallic stent. He subsequently developed a delayed pancreatic fistula due to main pancreatic duct disruption. An endoscopic nasopancreatic duct drainage tube was placed to bridge the main pancreatic duct disruption after removing the covered self-expandable metallic stent. In addition, endoscopic ultrasound-guided transmural drainage was performed for the infected fluid collection caused by the pancreatic fistula, and the clinical symptoms quickly improved. This case presents the possibility of a delayed pancreatic fistula due to self-expandable metallic stent deployment. The need for considering such delayed complications when placing self-expanding metallic stents is highlighted.

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.).

Efficacy of a novel self-expandable metal stent with dumbbell-shaped flare ends for distal biliary obstruction due to unresectable pancreatic cancer

This study aimed to evaluate the efficacy of a novel fully covered self-expandable metal stent (SEMS) with dumbbell-shaped flare ends for the palliation of distal biliary obstruction (DBO) due to unresectable pancreatic cancer (UPC). Patients with DBO due to UPC who received the novel HILZO fully covered stent (HFS), the WALLFLEX partially covered stent (WPS) or fully covered stent (WFS) were analyzed. The incidence of recurrent biliary obstruction (RBO), time to RBO (TRBO), and the incidence of complications were compared among the three SEMS groups. Eighty-four patients (HFS, n = 36; WPS, n = 20; WFS, n = 28) were included. The incidence of RBO was low in the HFS group (versus the WPS and WFS group, p = 0.033 and 0.023, respectively). TRBO in the HFS group was longer than that in the WFS group (p = 0.049). Placement of the HFS was an independent factor for long TRBO in multivariable analysis (p = 0.040). The incidence of pancreatitis and cholecystitis in the HFS group was low (one for each). It is recommended to use the HFS for the palliation of DBO due to UPC from the viewpoint of the low incidence of RBO and complications.

Endoscopic palliation of malignant biliary obstruction

Malignant biliary obstruction often presents with challenges requiring the endoscopist to assess the location of the lesion, the staging of the disease, the eventual resectability and patient preferences in term of biliary decompression. This review will focus on the different modalities available in order to offer the most appropriate palliation, such as conventional endoscopic retrograde cholangiopancreatography, endoscopic ultrasound guided biliary drainage as well as ablative therapies including photodynamic therapy or radiofrequency ablation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cholecystectomy before, simultaneously, or after ERCP in patients with acute cholecystitis: A protocol for systematic review and/or meta analysis

INTRODUCTION

Cholecystectomy is the intervention of choice for treating acute cholecystitis; when conservative management does not work, it operates on the patient outside the critical condition. It can be performed together with or after endoscopic papillotomy through endoscopic retrograde cholangiopancreatography (ERCP) when it is concurrent with a situation of cholechodocolithiasis or when there is compression and consequent increase in pressure in the bile duct caused by a calculus jammed in the vesicular infundibulum (Mirizzi's syndrome), with or without jaundice, fever, and pain in the right hypochondrium (Charcot's Triad), which can progress to sepsis of biliary origin. This review aims to assess whether the timing of cholecystectomy (before or after ERCP) interferes with the postoperative period and clinical outcome in patients with acute cholecystitis.

METHODS AND ANALYSIS

By searching the MEDLINE/PubMed, Embase, Web of Science, ScienceDirect, ClinicalTrials.gov, CINAHAL, Latin American and Caribbean Literature in Health Sciences, Scopus and Cochrane Central databases, Controlled Trials Registry Randomized clinical trials will be searched to analyze whether ERCP performed before or after open or laparoscopic cholecystectomy (LC) in patients with acute cholecystitis is beneficial or not, through the analysis of postoperative complications. No language or publication period restrictions will be imposed. The primary outcome will be postoperative complications (postoperative morbidity and mortality). Four independent reviewers will select the studies and extract data from the original publications, with a fifth reviewer in case of disagreement regarding the inclusion or not of particular research in the present review. The risk of bias will be assessed using The Risk of Bias 2 (RoB 2.0) tool, and the certainty of evidence will be evaluated using the grading of recommendations assessment, development, and evaluation. Data synthesis will be performed using the Review Manager software (RevMan V.5.2.3). To assess heterogeneity, we will calculate the I2 statistics. Additionally, a quantitative synthesis will be performed if the included studies are sufficiently homogeneous.

ETHICS AND DISCLOSURE

Since the present study will review secondary data, previously published and scientifically validated, it will not be necessary to obtain ethical approval. The results of this systematic review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

International Prospective Registry of Systematic Reviews (PROSPERO) CRD42021290726.

Current endoscopic approaches to biliary strictures

PURPOSE OF REVIEW

To summarize the current status and future perspectives of the endoscopic management of biliary strictures.

RECENT FINDINGS

In addition to conventional diagnostic modalities, such as cross-sectional imaging and endoscopic ultrasonography (EUS), per-oral cholangioscopy is helpful for indeterminate biliary strictures. It allows direct visualization of the biliary tract and targeted biopsy. For distal malignant biliary obstruction (MBO), a self-expandable metal stent (SEMS) via endoscopic retrograde cholangiopancreatography (ERCP) is a standard of care. EUS-guided biliary drainage (EUS-BD) is an emerging alternative to percutaneous transhepatic biliary drainage in cases with failed ERCP. EUS-BD is also an effective salvage option for perihilar MBO, which can not be managed via ERCP or percutaneous transhepatic biliary drainage. Preoperative drainage is necessary for most jaundiced patients as neoadjuvant chemotherapy is widely administered for resectable and borderline resectable pancreatic cancer, and a SEMS is preferred in this setting, too. For benign biliary strictures, a covered SEMS can improve stricture resolution and reduce the number of endoscopic sessions as compared to plastic stents.

SUMMARY

ERCP and EUS play a central role in the diagnosis and drainage for both malignant and benign biliary strictures.

Covered versus uncovered metal stent for endoscopic drainage of a malignant distal biliary obstruction: Meta-analysis

OBJECTIVES

The role of a covered vs. an uncovered self-expandable metal stent (SEMS) for malignant distal biliary obstruction (MDBO) is not clear. This meta-analysis compared the efficacy of covered vs. uncovered SEMS for patients with MDBO after endoscopic insertion.

METHODS

A systematic meta-analysis of all relevant articles listed in PubMed, the Cochrane Library, and Google Scholar databases was performed. Fixed effects or random effects models were used to investigate pooled effects with 95% confidence intervals (CIs).

RESULTS

The meta-analysis included 2358 patients from 12 eligible studies. Time to recurrent biliary obstruction (RBO) was significantly longer for covered SEMS (mean difference, 45.51 days; 95% CI 11.79-79.24). Although there was no significant difference in the RBO rate, subgroup analysis in pancreatic cancer occupying more than 90% (PC) revealed that the RBO rates were significantly lower for covered SEMS (odds ratio [OR] 0.43, 95% CI 0.25-0.74). Stent migration, sludge formation, and overgrowth were significantly more common with a covered SEMS (OR 7.92, 95% CI 4.01-15.64; OR 3.25, 95% CI 1.89-5.59; OR 2.03, 95% CI 1.20-3.43, respectively). The rate of ingrowth was significantly lower for covered SEMS. There was no significant difference in total procedure-related adverse events between the two types of SEMS.

CONCLUSIONS

A covered SEMS is superior to an uncovered SEMS with respect to prevention of RBO in patients with MDBO, particularly those caused by PC.

Angle of covered self-expandable metallic stents after placement is a risk factor for recurrent biliary obstruction

BACKGROUND

Studies have shown that covered self-expandable metallic stents (CSEMS) with a low axial forces after placement can cause early recurrent biliary obstruction (RBO) due to precipitating sludge formation.

AIM

To ascertain whether the angle of CSEMS after placement is a risk factor for RBO in unresectable distal malignant biliary obstruction (MBO).

METHODS

Between January 2010 and March 2019, 261 consecutive patients underwent self-expandable metallic stent insertion by endoscopic retrograde cholangiopancreatography at our facility, and 87 patients were included in this study. We evaluated the risk factors for RBO, including the angle of CSEMS after placement as the primary outcome. We measured the obtuse angle of CSEMS after placement on an abdominal radiograph using the SYNAPSE PACS system. We also evaluated technical and functional success, adverse events, time to RBO (TRBO), non-RBO rate, survival time, cause of RBO, and reintervention procedure as secondary outcomes.

RESULTS

We divided the patients into two cohorts based on the presence or absence of RBO. The angle of CSEMS after placement (per 1° and per 10°) was evaluated using the multivariate Cox proportional hazard analysis, which was an independent risk factor for RBO in unresectable distal MBO [hazard ratio, 0.97 and 0.71; 95% confidence interval (CI): 0.94-0.99 and 0.54-0.92; P = 0.01 and 0.01, respectively]. For early diagnosis of RBO, the cut-off value of the angle of CSEMS after placement using the receiver operating characteristic curve was 130° [sensitivity, 50.0%; specificity 85.5%; area under the curve 0.70 (95%CI: 0.57-0.84)]. TRBO in the < 130° angle group was significantly shorter than that in the ≥ 130° angle group (P < 0.01).

CONCLUSION

This study suggests that the angle of the CSEMS after placement for unresectable distal MBO is a risk factor for RBO. These novel results provide pertinent information for future stent management.

Biliary metal stents should be placed near the hilar duct in distal malignant biliary stricture patients

BACKGROUND

Endoscopic biliary drainage using a self-expandable metallic stent (SEMS) has been widely performed to treat distal malignant biliary obstruction (DMBO). However, the optimal position of the stent remains unclear.

AIM

To determine the ideal position for SEMS placement.

METHODS

In total, 135 DMBO patients underwent SEMS (uncovered or covered) placement over a ten-year period. A total of 127 patients with biliary obstruction between the junction of the cystic duct and Vater's papilla were enrolled. An SEMS was placed through the upper common bile duct 2 cm from the biliary hilar duct in 83 patients (Hilar group) or near the top of the biliary obstruction in 44 patients (Lower group). Technical and functional success, adverse events, and risk factors for SEMS dysfunction were evaluated.

RESULTS

The stent patency period was significantly longer in the Hilar group than in the Lower group (P value < 0.01). In multivariate analysis, the only statistically significant risk factor for SEMS dysfunction was being in the Lower group (hazard ratio: 9.94, 95% confidence interval: 2.25-44.0, P < 0.01).

CONCLUSION

A longer patency period was achieved by positioning the SEMS near the biliary hilar duct.

Laser-cut-type versus braided-type covered self-expandable metallic stents for distal biliary obstruction caused by pancreatic carcinoma: a retrospective comparative cohort study

BACKGROUND/AIMS

Covered self-expandable metallic stents (CMSs) are widely used for malignant distal biliary obstructions (MDBOs) caused by pancreatic carcinoma. This study compared the efficacy and safety of the laser-cut-type and braided-type CMSs.

METHODS

To palliate MDBOs caused by pancreatic carcinoma, the laser-cut-type CMSs was used from April 2014 to March 2017, and the braided-type CMSs was used from April 2017 to March 2019. The tested self-expandable metallic stents were equipped with different anti-migration systems.

RESULTS

In total, 47 patients received CMSs for MDBOs (24 laser-cut type, 23 braided-type). The time to recurrent biliary obstruction (TRBO) was significantly longer in the braided-type CMSs (p=0.0008), and the median time to stent dysfunction or patient death was 141 and 265 days in the laser-cut-type CMSs and braided-type CMSs, respectively (p=0.0023). Stent migration was the major cause of stent dysfunction in both groups, which occurred in 37.5% of the laser-cut-type CMSs and 13.0% of the braidedtype CMSs. There were no differences in the survival duration between the groups.

CONCLUSION

The TRBO was significantly longer for the braided-type CMSs with an anti-migration system than for the laser-cuttype. Stent migration tended to be less frequent with the braided-type CMSs than with the laser-cut-type CMSs.