Risk factors for pancreatitis following transpapillary self-expandable metal stent placement

Delayed Acute Pancreatitis After Transpapillary Gallbladder Drainage With Plastic Stents

Endoscopic retrograde cholangiopancreatography-guided transpapillary gallbladder drainage has emerged as an effective alternative for management of acute cholecystitis in nonoperable candidates. Delayed acute pancreatitis has not been previously described as an adverse event with this procedure. In this article, we describe 3 patients who developed acute pancreatitis between 2 and 6 weeks after stent insertion with no alternative inciting cause. Delayed acute pancreatitis may represent a rare and previously uncharacterized adverse event related to transpapillary gallbladder drainage.

Computed tomography-based prediction of pancreatitis following biliary metal stent placement with the convolutional neural network

Background and study aims Pancreatitis is a potentially lethal adverse event of endoscopic transpapillary placement of a self-expandable metal stent (SEMS) for malignant biliary obstruction (MBO). Deep learning-based image recognition has not been investigated in predicting pancreatitis in this setting. Patients and methods We included 70 patients who underwent endoscopic placement of a SEMS for nonresectable distal MBO. We constructed a convolutional neural network (CNN) model for pancreatitis prediction using a series of pre-procedure computed tomography images covering the whole pancreas (≥ 120,960 augmented images in total). We examined the additional effects of the CNN-based probabilities on the following machine learning models based on clinical parameters: logistic regression, support vector machine with a linear or RBF kernel, random forest classifier, and gradient boosting classifier. Model performance was assessed based on the area under the curve (AUC) in the receiver operating characteristic analysis, positive predictive value (PPV), accuracy, and specificity. Results The CNN model was associated with moderate levels of performance metrics: AUC, 0.67; PPV, 0.45; accuracy, 0.66; and specificity, 0.63. When added to the machine learning models, the CNN-based probabilities increased the performance metrics. The logistic regression model with the CNN-based probabilities had an AUC of 0.74, PPV of 0.85, accuracy of 0.83, and specificity of 0.96, compared with 0.72, 0.78, 0.77, and 0.96, respectively, without the probabilities. Conclusions The CNN-based model may increase predictability for pancreatitis following endoscopic placement of a biliary SEMS. Our findings support the potential of deep learning technology to improve prognostic models in pancreatobiliary therapeutic endoscopy.

Outcomes of 6-mm diameter fully covered self-expandable metal stents for preoperative biliary drainage in pancreatic cancer

Background

10-mm self-expandable metal stents (SEMSs) are commonly used for preoperative biliary drainage in pancreatic cancer. However, smaller diameter SEMSs have attracted attention with the attempt to reduce stent-related adverse events (AEs).

Methods

We retrospectively analyzed consecutive borderline resectable pancreatic cancer patients who underwent neoadjuvant therapy and fully covered SEMS (FCSEMS) placement from April 2015 to May 2023. The primary outcome was stent-related non-event rate (NER), which was defined as the rate of completion of surgery without developing any preoperative events (recurrent biliary obstruction [RBO] or stent-related AEs). Secondary outcomes included stent-related AEs, causes of RBO, and cumulative incidence of RBO. Risk factors for pancreatitis, RBO, and stent migration were also examined.

Results

A total of 76 patients were included (6-mm group: 23; 10-mm group: 53). Stent-related NER (57% vs. 64%, p = 0.610), stent-related AEs (4% vs. 15%, p = 0.263), overall RBO rates (39% vs. 23%, p = 0.168), cumulative incidence of RBO (hazard ratio, 2.24; 95% confidence interval, 0.95-5.25; p = 0.065) were not significantly different between the two groups. Tumor involvement of the pancreatic duct was identified as a risk-reducing factor for pancreatitis, while an FCSEMS diameter of 6 mm was not identified as a risk factor for RBO and stent migration.

Conclusions

Stent-related NER was not significantly affected by FCSEMS diameter. Further studies are needed to confirm the usefulness of 6-mm diameter FCSEMS for preoperative biliary drainage in patients with borderline resectable pancreatic cancer.

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.

Safety of biliary drainage with 6-mm metallic stent for preoperative obstructive jaundice in pancreatic cancer: PURPLE SIX STUDY

BACKGROUND AND AIM

The 10-mm self-expandable metal stent (SEMS) is the standard for endoscopic transpapillary biliary drainage before pancreatic cancer surgery. However, the efficacy of stents thinner than 10 mm has not been adequately validated. Therefore, we aimed to evaluate the safety of a 6-mm fully covered SEMS (FCSEMS) for distal malignant biliary obstruction (DMBO) during preoperative chemotherapy for pancreatic cancer.

METHODS

This was a single-arm, multicenter, prospective phase II study of endoscopic transpapillary initial biliary drainage for DMBO before pancreatic cancer surgery. The primary endpoint was stent-related adverse events, and the key secondary endpoint was the non-recurrent biliary obstruction (non-RBO) rate during the observation period for both resectable (R) and borderline resectable (BR) pancreatic cancers.

RESULTS

The study enrolled 33 patients, among whom 32 received the study treatment. There were 23 and 9 cases of R and BR pancreatic cancers, respectively. The technical and clinical success rates were 97.0% and 90.1%, respectively. The stent-related adverse event rate was 3.1% (n = 1, acute pancreatitis) (95% confidential interval, 0.00-16.2), which met the criteria to be considered safe. The overall non-RBO rate during the observation period (median 96 days) was 78.1% (82.6% and 66.7% for R and BR pancreatic cancer cases, respectively).

CONCLUSIONS

The 6-mm FCSEMS is an extremely safe metallic stent with a low stent-related adverse event rate of 3.1% for preoperative biliary drainage in pancreatic cancer. It is considered the optimal stent for preoperative biliary drainage in terms of the non-RBO rate. UMIN Clinical Trial Registry (UMIN-CTR 000041704).

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

BACKGROUND AND AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Usefulness of Intraductal Placement of a Dumbbell-Shaped Fully Covered Self-Expandable Metal Stent for Post-Cholecystectomy Bile Leaks

Background and aims: In the treatment of post-cholecystectomy bile leaks, endoscopic naso-biliary drainage (ENBD) or biliary stenting using plastic stents is the standard of care. Fully covered self-expandable metal stent (FCSEMS) placement across the sphincter of Oddi is considered a salvage therapy for refractory cases, but pancreatitis and migration are the major concerns. Intraductal placement of a dumbbell-shaped FCSEMS (D-SEMS) could avoid these drawbacks of FCMSESs. In this retrospective study, we investigated the usefulness of intraductal placement of the D-SEMS for post-cholecystectomy bile leaks. Methods: Six patients who underwent intraductal placement of the D-SEMS for post-cholecystectomy bile leaks were enrolled. This method was performed as initial treatment in three patients and as salvage treatment in three ENBD refractory cases. Results: Technical and clinical successes were obtained in 6 (100%) patients and 5 (83%) patients, respectively. One clinically unsuccessful patient required laparoscopic peritoneal lavage. The early adverse event was one case of mild pancreatitis (17%). The median duration of the D-SEMS indwelling was 61 days (42-606 days) with no migration cases, all of which were successfully removed. The median follow-up after index ERCP was 761 (range: 161-1392) days with no cases of recurrent bile leaks. Conclusions: Intraductal placement of the D-SEMS for post-cholecystectomy bile leaks might be safe and effective even in refractory cases.

Comparison of the mechanical properties of retrieval basket catheters for bile duct stones: An experimental study

BACKGROUND

Although numerous retrieval baskets are currently available for the extraction of bile duct stones, their mechanical properties have not been evaluated. This study aimed to ascertain the characteristics of retrieval baskets for bile duct stones by examining their mechanical properties.

METHODS

This experimental study tested the mechanical properties of seven retrieval baskets for bile duct stones. The radial force (RF) was measured using a dedicated measurement device and the axial force (AF) was measured using the conventional manual method.

RESULTS

The mean RF differed significantly among the baskets (p < 0.001) and was the strongest for VorticCatch (1.62 N ± 0.02) and COAXIS (1.62 N ± 0.04), followed by RASEN (1.27 N ± 0.02), Memory Basket (0.95 N ± 0.01), 8-wire Nitinol Basket (0.93 N ± 0.01), StoneHunter (0.78 N ± 0.01) and Flower Basket (0.37 N ± 0.01), respectively. The mean AF differed significantly among the baskets (p < 0.001) and was the highest for VorticCatch (0.668 N ± 0.032), followed by COAXIS (0.629 N ± 0.041), StoneHunter (0.574 N ± 0.037), 8-wire Nitinol Basket (0.546 N ± 0.010), Memory Basket (0.542 N ± 0.024), RASEN (0.435 N ± 0.008) and Flower Basket (0.297 N ± 0.011), respectively. The baskets were categorized into four groups with comparable mechanical properties based on the RF and AF: group 1, low RF and low AF; group 2, moderate RF and moderate AF; group 3, high RF and moderate AF; and group 4, high RF and high AF.

CONCLUSIONS

This study revealed distinct mechanical properties of various retrieval baskets used for extracting bile duct stones, which may enhance the understanding of their action. Our results could also aid the development of retrieval baskets in future.

Evaluation of the mechanical properties of current biliary self-expandable metallic stents: axial and radial force, and axial force zero border

BACKGROUND/AIMS

Mechanical properties (MPs) and axial and radial force (AF and RF) may influence the efficacy and complications of self-expandable metallic stent (SEMS) placement. We measured the MPs of various SEMSs and examined their influence on the SEMS clinical ability.

METHODS

We evaluated the MPs of 29 types of 10-mm SEMSs. RF was measured using a conventional measurement device. AF was measured using the conventional and new methods, and the correlation between the methods was evaluated.

RESULTS

A high correlation in AFs was observed, as measured by the new and conventional manual methods. AF and RF scatterplots divided the SEMSs into three subgroups according to structure: hook-and-cross-type (low AF and RF), cross-type (high AF and low RF), and laser-cut-type (intermediate AF and high RF). The hook-and-cross-type had the largest axial force zero border (>20°), followed by the laser-cut and cross types.

CONCLUSION

MPs were related to stent structure. Hook-and-cross-type SEMSs had a low AF and high axial force zero border and were considered safest because they caused minimal stress on the biliary wall. However, the increase in RF must be overcome.

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.

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.

Efficacy of pancreatic duct stenting to prevent postendoscopic retrograde cholangiopancreatography pancreatitis after covered self-expandable metal stent deployment

OBJECTIVES

Although covered self-expandable metal stents (CSEMSs) are associated with the risk of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis due to pancreatic duct (PD) orifice obstruction, they are often used for biliary drainage treatment in malignant biliary obstruction (MBO). This study aimed to investigate the efficacy of PD stenting in preventing post-ERCP pancreatitis after CSEMS implantation.

METHODS

This retrospective cohort study analyzed 554 patients with transpapillary CSEMS for MBO. Patients with noninitial deployment, benign disease, CSEMS deployment above the papilla, surgically altered anatomy, uncovered self-expandable metal stents, multiple thin self-expandable metal stents, and unavailable procedure videos were excluded. Logistic regression analysis estimated the association between PD stenting and post-ERCP pancreatitis incidence. We adjusted for age, sex, pancreatitis history, prophylactic rectal nonsteroidal anti-inflammatory drug use, naïve papilla, MBO etiology, and prolonged biliary cannulation time.

RESULTS

Among 554 patients, 67 (12.1%) experienced post-ERCP pancreatitis. Post-ERCP pancreatitis was recorded in 13.7% of patients in the non-PD stenting and 4.3% in the PD stenting groups. Pancreatic duct stenting was associated with lower risks of post-ERCP pancreatitis (odds ratio [OR] 0.28; 95% confidence interval [CI] 0.099-0.79; P = 0.028). In multivariable analysis, the association between PD stenting and lower post-ERCP pancreatitis incidence was consistent (OR 0.19; 95% CI 0.062-0.58; P = 0.0034).

CONCLUSIONS

Pancreatic duct stenting could reduce the risk of post-ERCP pancreatitis after CSEMSs.

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.

Risk Factors Associated with Acute Pancreatitis after Percutaneous Biliary Intervention: We Do Not Know Nearly Enough

Percutaneous transhepatic cholangiodrainage (PTCD) and percutaneous transhepatic biliary stenting (PTBS) may be used as a palliative treatment for inoperable patients with malignant biliary obstruction (MBO) to improve the prognosis and their quality of life. However, acute pancreatitis is a common and severe complication that cannot be ignored after PTCD and PTBS in patients with MBO. A few cases may develop severe pancreatitis with a higher mortality rate. In this study, we summarize the known risk factors for acute pancreatitis after percutaneous biliary interventional procedures and investigate possible risk factors to reduce its occurrence by early identifying high-risk patients and taking appropriate measures.

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.).

Technical Feasibility, Short-Term Patency, Safety, and Efficacy of Percutaneously Delivered Double Pig-Tail Stent for Palliation of Unresectable Biliary Malignancies

Purpose The aim of this study was to evaluate the technical feasibility, complication rate, and efficacy of percutaneously delivered plastic biliary stent, compared with that of internal–external biliary drainage catheter.

Methods Patients with unresectable malignant biliary obstruction were included who underwent percutaneous transhepatic biliary drainage and double pigtail plastic stenting (DPT-PS) or internal–external biliary drainage catheter in 15 months' duration.

Results Seventy-seven patients were included in the study who underwent DPT-PS (n = 37) or internal external drainage catheter placement (n = 40). Overall, the technical success rate for percutaneous plastic stenting was 92.5% and technical success rate for primary stenting at the time of initial puncture was 62%. The incidence of fever and hemobilia was similar across the two groups, whereas bile leakage in the perihepatic space and through the skin at puncture site was higher in patients with internal–external drainage catheter. Both the techniques were effective in reducing the bilirubin levels of patients. Re-intervention was done in five patients in DPT-PS and six patients with ring biliary catheter.

Conclusion DPT-PS may be used as a viable cost-efficient alternative for unresectable biliary malignancies with low post-procedure life expectancy

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.

The Feasibility of Whole-Liver Drainage with a Novel 8 mm Fully Covered Self-Expandable Metal Stent Possessing an Ultra-Slim Introducer for Malignant Hilar Biliary Obstructions

BACKGROUND

In the case of an unresectable malignant hilar biliary obstruction (MHBO), the optimal drainage method has not yet been established. Recently, an 8 mm, fully covered, self-expandable metal stent (FCSEMS) with an ultra-slim introducer has become available. In this article, the results of whole-liver drainage tests using this novel FCSEMS for MHBO are reported.

METHODS

Unresectable MHBOs up to Bismuth IIIa with strictures limited to the secondary branches were eligible. The proximal end of the stent was placed in such a way as to avoid blocking the side branches, and the distal end was placed above the papilla when possible. Consecutive patients treated between April 2017 and January 2021 were retrospectively analyzed. The technical and functional success rates, rates and causes of recurrent biliary obstruction (RBO), time to RBO (TRBO), revision for RBO, and adverse events (AEs) were evaluated.

RESULTS

Eleven patients (Bismuth I/II/IIIa: 1/7/3) were enrolled. Two stents were placed in nine patients and three were placed in two patients. Both the technical and functional success rates were 100%. RBO occurred in four (36%) patients due to sludge formation. Revision was performed for three patients, with the successful removal of all stents. The median TRBO was 187 days, and no late AEs other than the RBO occurred. Regarding the distal position of the stent, the RBO rate was significantly lower (14.3% vs. 75%, p = 0.041) and the cumulative TRBO was significantly longer (median TRBO: not reached vs. 80 days, p = 0.031) in the case of the placement above the papilla than the placement across the papilla.

CONCLUSION

For unresectable MHBOs of Bismuth I, II, and IIIa, whole-liver drainage with a novel 8 mm FCSEMS possessing an ultra-slim introducer was feasible and potentially safe, with favorable stent patency. Placement above the papilla might be preferrable to placement across the papilla.

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.

A Risk Prediction Model for Post-endoscopic Retrograde Cholangiopancreatography Pancreatitis After Stent Insertion for Malignant Biliary Obstruction: Development and Validation

OBJECTIVES

Pancreatitis is the most common complication of post-endoscopic retrograde cholangiopancreatography (ERCP). There are currently no prediction models, particularly for post-ERCP pancreatitis (PEP) after biliary stent placement due to malignant biliary obstruction (MBO). To that end, we aim to develop and validate a predictive model for PEP.

METHODS

We retrospectively analyzed the data of patients who underwent ERCP for biliary stent placement due to MBO at the Second Affiliated Hospital of Harbin Medical University from January 1, 2014 to August 31, 2021. The eligible patients were randomly allocated to the development and validation cohorts. A prediction model was built using the development cohort, and the model's effect was validated using a validation cohort.

RESULTS

A total of 1524 patients were enrolled, including 1016 in the development cohort and 508 in the validation cohort, with an overall PEP rate of 7.1%. The model's predictors included acute pancreatitis history, the absence of pancreatic duct dilation, nonpancreatic cancer, difficult cannulation, and pancreatic injection. The area under the curve (AUC) in the development cohort was 0.810, and the incidence of PEP in the low-risk, medium-risk, and high-risk groups was 1.53%, 9.12%, and 36.36%, respectively. Meanwhile, the AUC of the validation cohort was 0.781, and the incidence of PEP in the low-risk, medium-risk, and high-risk groups was 4.17%, 8.75%, and 41.67%, respectively.

CONCLUSIONS

This study was the first to build and validate a risk prediction model, especially for PEP after biliary stent placement due to MBO. Moreover, this model might assist clinicians in identifying high-risk patients and help implement preventive measures in a more timely manner.

How to successfully administer palliative treatment with a stent for malignant gastric outlet obstruction?

Although endoscopic stenting (ES) has been widely used as a less-invasive palliation method for malignant gastric outlet obstruction (GOO), recent reports have highlighted issues related to the procedure. For successful treatment, various aspects must be assessed before considering the practices. First, it is necessary to eliminate cases with contraindications such as coexistence of distal small-bowel obstruction or perforation. Other factors potentially related to clinical failure (i.e., peritoneal carcinomatosis) may require consideration but remain controversial. ES has better short-term outcomes than surgical gastrojejunostomy (GJ). GJ has recently been considered preferable in cases with longer life expectancy because of superior sustainability. Various types of stents are now commercially available, but their ideal structure and mechanical properties have not yet been clarified. Covered metal stent may reduce stent obstruction but is prone to increase stent migration, and its significance remains uncertain. Subsequent chemotherapy after stenting should be considered, as it is expected to prolong patient survival without increasing the risk of adverse events. Furthermore, it may be helpful in preventing tumor ingrowth. In cases with GOO combined with biliary obstruction, biliary intervention is often difficult. Recently, endoscopic ultrasound-guided biliary drainage (EUS-BD) has been widely used as an alternative procedure for endoscopic transpapillary biliary drainage (ETBD). Despite the lack of consensus as to whether ETBD or EUS-BD is preferred, EUS-BD is useful as a salvage technique for cases where ETBD is difficult. To perform stent placement successfully, it is important to pay attention to the above points; however, many remaining issues need to be clarified in the future.

Efficacy of 6‐mm diameter fully covered self‐expandable metallic stents in preoperative biliary drainage for pancreatic ductal adenocarcinoma

Objectives

Methods

Results

Conclusion

Prevention of pancreatitis after stent implantation for distal malignant biliary strictures: systematic review and meta-analysis

INTRODUCTION

Biliary stent placement remains a palliative treatment for patients with unresectable distal malignant biliary strictures (DMBS). The incidence of post-ERCP-pancreatitis (PEP) significantly increases in patients receiving fully covered self-expandable metal stents (FCSEMS) who undergo endoscopic retrograde cholangiopancreatography (ERCP).

AREAS COVERED

This review provides an overview of prevention of PEP after stent implantation for DMBSs. The following operational variables were evaluated: (1) stent type (plastic or metal stent); (2) stent location (above or across the sphincter of Oddi); (3) prophylactic pancreatic duct stent placement; (4) endoscopic sphincterotomy (EST). PubMed, EMBASE, and Cochrane database were searched to identify eligible studies up to October 2021. The odds ratio (OR) with 95% confidence intervals (CI) were pooled using fixed- or random- effects models.

EXPERT OPINION

1. PEP occurs more frequently in DMBS patients with self-expandable metal stents (SEMS) compared to that plastic stent (PS). 2. The PEP incidence is higher in covered stents than that in uncovered self-expandable metal stents (USEMS), but not significantly. 3. PEP incidence increases in patients receiving transpapillary FCSEMS placement, particularly when there is an absence of pancreatic duct dilation, and prophylactic pancreatic stenting is recommended for these patients. 4. Limited studies with small sample indicate that there is no significant difference in PEP incidence between transpapillary and suprapapillary stents placement for DMBS. 5. Limited studies indicate that EST does not significantly affect the incidence of pancreatitis in DMBS patients.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Dilated main pancreatic duct can be a negative predictor of pancreatitis related to biliary SEMS insertion across the papilla

OBJECTIVES

Post-ERCP pancreatitis (PEP) after self-expandable metallic stent (SEMS) insertion across the papilla of Vater is an important adverse event that affects the patient's quality of life (QOL). We examined the predictive factors of PEP after SEMS insertion to treat obstructive jaundice due to malignancy.

METHODS

Ninety patients who underwent biliary SEMS insertion for biliary obstruction due to malignancy at Iwata City Hospital between 2010 and 2018 were reviewed. We evaluated the relationship between the incidence of PEP after biliary SEMS insertion and clinical factors. We measured the thickness of the pancreatic parenchyma and diameter of the main pancreatic duct (MPD) at the left side of the corpus vertebrae.

RESULTS

Mild and severe PEP were diagnosed in 10 (11.1%) and 1 (1.1%) patients, respectively. Only the thickness of the pancreatic parenchyma and diameter of MPD significantly differed between the PEP and non-PEP groups. The incidence of PEP among patients whose thickness of the pancreatic parenchyma at the left side of the corpus vertebrae was less than 9.5 mm (0%) on computed tomography was lower than that in patients whose thickness was 9.5 mm or greater (34.4%). Similarly, a wider (5 mm or more) diameter of MPD (4.3%) reduced the incidence of PEP compared with a narrower diameter (40.0%). Logistic regression analysis revealed that the probability of PEP decreases 3.91 times for every 1-mm increase in MPD diameter (95% CI 1.23-12.4, p = .02).

CONCLUSION

Based on our study, a dilated MPD is a negative predictive factor of pancreatitis related to biliary SEMS insertion.

Evaluation of post-ERCP pancreatitis after biliary stenting with self-expandable metal stents vs. plastic stents in benign and malignant obstructions

Background and study aims  There are conflicting data regarding the risk of post-ERCP pancreatitis (PEP) with self-expandable metallic stents (SEMS) compared to polyethylene stents (PS) in malignant biliary obstructions and limited data related to benign obstructions. Patients and methods  A retrospective cohort study was performed of 1136 patients who underwent ERCP for biliary obstruction and received SEMS or PS at a tertiary-care medical center between January 2011 and October 2016. We evaluated the association between stent type (SEMS vs PS) and PEP in malignant and benign biliary obstructions. Results  Among the 1136 patients included in our study, 399 had SEMS placed and 737 had PS placed. Patients with PS were more likely to have pancreatic duct cannulation, pancreatic duct stent placement, double guidewire technique, sphincterotomy and sphincteroplasty as compared to the SEMS group. On multivariate analysis, PEP rates were higher in the SEMS group (8.0 %) versus the PS group (4.8 %) (OR 2.27 [CI, 1.22, 4.24]) for all obstructions. For malignant obstructions, PEP rates were 7.8 % and 6.6 % for SEMS and plastic stents, respectively (OR 1.54 [CI, 0.72, 3.30]). For benign obstructions the PEP rate was higher in the SEMS group (8.8 %) compared to the PS group (4.2 %) (OR 3.67 [CI, 1.50, 8.97]). No significant differences between PEP severity were identified based on stent type when stratified based on benign and malignant. Conclusions  PEP rates were higher when SEMS were used for benign obstruction as compared to PS. For malignant obstruction, no difference was identified in PEP rates with use of SEMS vs PS.

Efficacy of an internal anchoring plastic stent to prevent migration of a fully covered metal stent in malignant distal biliary strictures: a randomized controlled study

BACKGROUND

Two types of self-expandable metal stents (SEMS) are available for malignant distal biliary obstruction: fully covered SEMS (FCSEMS) and uncovered SEMS. FCSEMS can prevent stent ingrowth, but a major concern is spontaneous migration. This study aimed to determine whether the additional insertion of a double-pigtail plastic stent to anchor the FCSEMS can prevent migration.

METHODS

68 patients with unresectable, malignant, distal, biliary obstruction were included in this multicenter, randomized, superiority trial. The patients were randomly assigned to receive either the FCSEMS plus an anchoring plastic stent (n = 33) or an FCSEMS alone (n = 35). After placement of the FCSEMS, the anchoring stent was inserted inside the FCSEMS. The primary outcome was the rate of stent migration during the 6-month follow-up. The secondary outcomes were stent-related adverse events, stent patency, and survival rates.

RESULTS

The baseline characteristics were similar between the two groups. The rate of stent migration at 6 months was significantly lower in patients with the FCSEMS plus anchoring stent (15 % vs. 40 %; P = 0.02). The mean stent patency was significantly longer in the FCSEMS plus anchoring group (237 days [95 % confidence interval [CI] 199 to 275] vs. 173 days [95 %CI 130 to 217]; P = 0.048). There were no significant differences in stent-related adverse events and overall survival rates at 6 months between the two groups.

CONCLUSIONS

Our data suggest that the additional double-pigtail plastic stent anchored the FCSEMS to prevent migration and prolonged patency without any serious adverse events.

Development of Severe Acute Pancreatitis Following Uncovered Metallic Stent Placement: A Rare Case Report

Self-expandable metallic stents (SEMSs) are widely used for malignant biliary stricture (MBS). Acute pancreatitis is an early complication following SEMS placement. In the present case, the patient developed severe acute pancreatitis after SEMS placement for MBS because of metastatic lymph nodes. Endoscopic retrograde cholangiopancreatography, endoscopic sphincterotomy and an endoscopic nasobiliary drainage tube placement were performed. After seven days, an uncovered SEMS was placed; however, severe acute pancreatitis occurred, and the SEMS was drawn out emergently. In SEMS placement for patients with MBS caused by non-pancreatic cancer, SEMS should be selected carefully while considering each patient's case.

Antireflux metal stent for biliary obstruction: Any benefits?

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

A Prospective Multicenter Study of Partially Covered Metal Stents in Patients Receiving Neoadjuvant Chemotherapy for Resectable and Borderline Resectable Pancreatic Cancer: BTS-NAC Study

Background/Aims

The aim of this study was to evaluate the safety and efficacy of partially covered self-expandable metallic stents (PCSEMS) in patients undergoing neoadjuvant chemo(radio) therapy (NAC) for pancreatic cancer (PC).

Methods

This was a prospective multicenter study to evaluate the safety and efficacy of PCSEMS in patients receiving NAC for resectable and borderline resectable PC. The primary endpoint was the rate of recurrent biliary obstruction (RBO).

Results

Twenty-six patients with PC (three with resectable PC and 23 with borderline resectable PC) who underwent NAC at seven Japanese centers were included in the analysis. Both the technical and functional success rates of PCSEMS placement were 100%. Early stent-related complications were observed in three patients (11.5%): mild pancreatitis (n=2) and mild liver abscess (n=1). The median time to surgery or palliation was 4.0 months. Surgical resection was eventually performed in 73.1% of patients, and stent removal during surgery was successful in all patients. RBO was observed in nine patients (34.6%): seven with stent occlusion, one with kinking and one with migration. The RBO rates in resected cases and nonresected cases were 36.8% and 28.6%, respectively.

Conclusions

Biliary drainage by PCSEMS was safe and feasible in patients undergoing NAC for resectable and borderline resectable PC.

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.

Retrospective Comparative Study of Side-by-Side and Stent-in-Stent Metal Stent Placement for Hilar Malignant Biliary Obstruction

BACKGROUND

In patients with unresectable hilar malignant biliary obstruction (MBO), bilateral metal stent placement is recommended. However, treatment selection between partially stent-in-stent (SIS) and side-by-side (SBS) methods is still controversial.

STUDY

Clinical outcomes of bilateral metal stent placement by SBS and SIS methods for hilar MBO were retrospectively studied in four Japanese centers. While large-cell-type uncovered metal stents were placed above the papilla in SIS, braided-type uncovered metal stents were placed across the papilla in SBS.

RESULTS

A total of 64 patients with hilar MBO (40 SIS and 24 SBS) were included in the analysis. Technical success rate was 100% in SIS and 96% in SBS. Functional success rate was 93% in SIS and 96% in SBS. Early adverse event rates were higher in SBS (46%) than in SIS (23%), though not statistically significant (P = 0.09). Post-procedure pancreatitis was exclusively observed in SBS group (29%). Recurrent biliary obstruction rates were 48% and 43%, and the median time to recurrent biliary obstruction was 169 and 205 days in SIS and SBS, respectively.

CONCLUSIONS

Other than a trend to higher adverse event rates including post-procedure pancreatitis in SBS, clinical outcomes of SIS and SBS methods were comparable in patients with unresectable hilar MBO.

Novel risk factors for recurrent biliary obstruction and pancreatitis after metallic stent placement in pancreatic cancer

Background and study aims  Self-expandable metallic stents (SEMS) are now widely used even for patients with borderline resectable (BR) pancreatic cancer (PC), as neoadjuvant therapy has become common. Therefore, we conducted this study to evaluate safety of SEMS placement in the population including BR PC and to explore risk factors for recurrent biliary obstruction (RBO), pancreatitis, and cholecystitis. Patients and methods  We retrospectively investigated consecutive patients with PC who received initial SEMS between January 2015 and March 2019. We compared time to RBO (TRBO), causes of RBO, and stent-related adverse events (AEs) according to resectability status. Univariate and multivariate analyses were performed to explore risk factors for TRBO, pancreatitis, and cholecystitis. Results  A total of 135 patients were included (BR 31 and unresectable [UR] 104). Stent-related AEs occurred in 39 patients: pancreatitis 14 (mild/moderate/severe 1/6/7), cholecystitis 12, and non-occluding cholangitis 13. TRBO, causes of RBO, and stent-related AEs were not significantly different according to resectability status. Overall rate of RBO was higher in UR PC due to the longer follow-up period. Sharp common bile duct (CBD) angulation was an independent risk factor for short duration of TRBO. High pancreatic volume index and SEMS of high axial force were independent risk factors for pancreatitis, whereas tumor involvement to orifice of cystic duct was the only risk factor for cholecystitis. Conclusions  We demonstrated that SEMS can be safely deployed even in patients with BR PC. Sharp CBD angulation and high pancreatic volume index were identified as novel risk factors for RBO and pancreatitis, respectively, after SEMS placement.

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

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

Outcomes of EUS-guided choledochoduodenostomy as primary drainage for distal biliary obstruction with covered self-expandable metallic stents

Background and study aims  Endoscopic ultrasonography-guided choledochoduodenostomy (EUS-CDS) is an alternative therapy for percutaneous transhepatic biliary drainage. Outcomes of EUS-CDS for distal biliary tract obstruction with a covered self-expandable metallic stent (SEMS) as a primary drainage technique are unclear because there are few relevant reports. This study aimed to determine outcomes in patients undergoing EUS-CDS using SEMS as the primary drainage technique for malignant distal biliary duct obstruction. Patients and methods  This retrospective study was conducted at Aichi Cancer Center Hospital, from January 2010 to July 2018, using data from our database. Results  EUS-CDS was performed as a primary drainage technique for 92 patients. The technical success rate was 92.8 %, and the clinical success rate was 91.6 %. The overall incidence of adverse events was 15.7 %. The median stent patency time for the EUS-CDS was 396 days. Nineteen patients required re-intervention because of cholangitis or jaundice. Conclusion  EUS-CDS as a primary drainage technique using SEMS has high technical and clinical success rates. It should be considered an effective drainage method with respect to long-term stent patency, low re-intervention rates, and absence of severe complications.

Self-expandable metallic stent placement above the papilla without endoscopic sphincterotomy in patients with distal malignant biliary obstruction

Background and study aims  The best method for endoscopic placement of self-expandable metallic stents (SEMS) for distal malignant biliary obstruction (MBO) has not yet been determined. The aim of this study was to evaluate how SEMS placement above the papilla and without endoscopic sphincterotomy (EST) impacts the time to recurrent biliary obstruction (RBO) in patients with distal MBO. Patients and methods  We retrospectively reviewed data for 73 consecutive patients with unresectable distal MBO who underwent endoscopic SEMS placement for the first time at our institution between April 2014 and March 2016. We compared time to RBO of SEMS placement above the papilla (intraductal placement) with SEMS placement across the papilla (transpapillary placement). In the intraductal placement group, we also compared time to RBO of placement without EST with placement with EST. Results  Endoscopic SEMS placement was performed in 30 patients with intraductal placement and in 43 patients with transpapillary placement. The median time to RBO was significantly longer with intraductal placement (307 days) than with transpapillary placement (161 days) ( P  = 0.022). Complication rates did not differ between the two groups. In both univariate and multivariate analysis, intraductal placement was an independent factor contributing to prolonged time to RBO. In intraductal placement, time to RBO was significantly longer in SEMS placement without EST than with EST (363 days vs. 227 days, respectively; P  = 0.026). Conclusions  Intraductal SEMS placement, especially without EST for distal MBO contributed to longer time to RBO.

International consensus statements for endoscopic management of distal biliary stricture

Distal biliary strictures (DBS) are common and may be caused by both malignant and benign pathologies. While endoscopic procedures play a major role in their management, a comprehensive review of the subject is still lacking. Our consensus statements were formulated by a group of expert Asian pancreatico-biliary interventional endoscopists, following a proposal from the Digestive Endoscopy Society of Taiwan, the Thai Association for Gastrointestinal Endoscopy, and the Tokyo Conference of Asian Pancreato-biliary Interventional Endoscopy. Based on a literature review utilizing Medline, Cochrane library, and Embase databases, a total of 19 consensus statements on DBS were made on diagnosis, endoscopic drainage, benign biliary stricture, malignant biliary stricture, and management of recurrent biliary obstruction and other complications. Our consensus statements provide comprehensive guidance for the endoscopic management of DBS.

Endoscopic sphincterotomy to prevent post-ERCP pancreatitis in patients with biliary neoplasms: a multicenter retrospective cohort study

Background and aims  Treatment of biliary neoplasms often involves multiple endoscopic retrograde cholangiopancreatography (ERCP)-related procedures. Endoscopic sphincterotomy (ES) may prevent post-ERCP pancreatitis (PEP). This retrospective, multicenter cohort study aimed to investigate the effectiveness of ES for prevention of PEP in patients with biliary neoplasm. Methods  Patients with biliary duct neoplasm who underwent ERCP between January 2006 and December 2016 were enrolled. The frequency of PEP was compared between the ES and non-ES groups using propensity score analysis. The effectiveness of ES in subgroups of patients who underwent biliary duct stent placement, intraductal ultrasound (IDUS), and transpapillary biliary duct biopsy was analyzed by logistic regression. Results  Of the 362 patients enrolled, 84 (23.2 %) developed PEP. Propensity score matching for PEP risk factors in 172 ERCP procedures showed that the frequency of PEP in the ES group was lower than that in the non-ES group (19.7 % vs. 33.7 %). Non-ES was also an independent risk factor for PEP in patients who underwent intraductal ultrasound and transpapillary biliary duct biopsy (RR = 4.54 and 5.26), but was not an independent risk factor for PEP in patients with biliary duct stents. In addition, there was no evidence that the frequency of PEP was statistically different between patients with plastic stents and metal stents in the ES and non-ES groups ( P  = 0.14 and 0.10). Conclusions  ES is an effective technique to prevent PEP in patients with biliary neoplasms. In particular, ES is a safe technique to prevent PEP when performing IDUS and transpapillary biliary duct biopsy.

Acute pancreatitis after percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer

AIM

To investigate the incidence and clinical characteristics of acute pancreatitis following percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer. The clinical efficacy of metallic stent insertion was also evaluated.

MATERIALS AND METHODS

Data from 143 patients (75 men, 68 women; mean age, 65.8 years; range, 35-88 years) with unresectable pancreatic cancer who underwent percutaneous metallic biliary stent insertion between March 2007 and December 2017 were evaluated retrospectively. The incidence and clinical characteristics of acute pancreatitis were analysed. Stent patency and patient survival rates were calculated by Kaplan-Meier analysis.

RESULTS

Technical success was achieved in all patients. Among 31 patients with serum amylase levels above normal values (30-110 U/l), only nine had symptoms of acute pancreatitis (incidence, 6.4%). No statistically significant risk factors were identified. Pancreatitis was successfully managed with conservative treatment at a mean of 2.9 days (range, 1-4 days). The median stent patency and patient survival times were 117 days (95% confidence interval [CI], 87-148 days) and 150 days (95% CI, 125-174.9 days), respectively.

CONCLUSIONS

Acute pancreatitis was a relatively rare complication after percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer, and no significant risk factors were identified. Therefore, insertion of metallic biliary stents was seen to be a feasible and effective treatment approach in this patient group.

Modified non-flared fully covered self-expandable metal stent versus plastic stent for preoperative biliary drainage in patients with resectable malignant biliary obstruction

BACKGROUND AND AIM

Fully covered self-expandable metal stents (FCSEMS) may be better than plastic stents (PS) for preoperative biliary drainage (PBD) to relieve cholangitis or jaundice for resectable malignant biliary obstruction (MBO). However, modification of current FCSEMS designed originally for nonresectable MBO is needed to be a proper stent for PBD. The aim of this study was to evaluate the possible superiority of non-flared modified FCSEMS (M-FCSEMS) with 12-mm diameter and waist of central portion over PS in patients with resectable MBO.

METHODS

Eighty-five consecutive patients underwent PBD followed by operation from August 2015 to December 2017. In each M-FCSEMS and PS group, 29 patients were matched for age, sex, body mass index, and preoperative albumin and bilirubin levels.

RESULTS

The overall technical success rates of PBD using M-FCSEMS and PS were 100%. The time to operation was similar between groups (18.6 ± 10.8 vs 19.3 ± 11.6 days, respectively; P = 0.843). The prevalence of PBD-related adverse events (AEs) was 6.9% (2/29) in the M-FCSEMS group versus 27.6% (8/29) in the PS group (P = 0.037). Re-intervention before operation was required in 20.7% (6/29) of patients in the PS group but no patients in the M-FCSEMS group (P = 0.023). No differences were found between perioperative AEs in the M-FCSEMS and PS groups (27.5% vs 31.0%, respectively; P = 0.773).

CONCLUSION

Modified FCSEMS led to lower PBD-related AEs, re-intervention rate, and comparable perioperative AEs compared with PS. M-FCSEMS may be a potential novel stent for PBD in patients with resectable MBO.

Risk Factors for Pancreatitis and Cholecystitis after Endoscopic Biliary Stenting in Patients with Malignant Extrahepatic Bile Duct Obstruction

Background/Aims:

For the treatment of malignant biliary obstruction, endoscopic retrograde biliary drainage (ERBD) has been widely accepted as a standard procedure. However, post-ERBD complications can affect the lives of patients. The purpose of this study was to identify the predictive factors for these complications, including the patient’s status, cancer status, and stent type.

Methods:

This was a retrospective analysis conducted in a single tertiary hospital from January 2007 to July 2017. The following variables were evaluated: sex, age, body mass index, cancer type, history of pancreatitis, gallbladder stone, previous biliary stenting, precut papillotomy, stent type, contrast injection into the pancreatic duct or gallbladder, cystic duct invasion by the tumor, and occlusion of the cystic duct orifice by a metal stent.

Results:

Multivariate analysis showed that contrast injection into the pancreatic duct was a risk factor for pancreatitis. Patients with a history of bile drainage showed a lower risk of pancreatitis. For cholecystitis, the analysis revealed contrast injection into the gallbladder and cystic duct invasion by the tumor as important predictive factors. Metal stents showed a greater risk of post-procedure pancreatitis than plastic stents, but did not affect the incidence of cholecystitis.

Conclusions:

Considering that contrast injection is the most important factor for both complications, a careful approach by the physician is essential in preventing the occurrence of any complications. Further, choosing the type of stent is an important factor for patients at a risk of post-procedure pancreatitis.

Endoscopic Sphincterotomy before Fully Covered Metal Stent Placement Is Not Required for Distal Malignant Biliary Stricture due to a Pancreatic Head Tumor

Background/Aims

Endoscopic sphincterotomy (EST) is often performed before fully covered self-expandable metal stent (FCSEMS) placement in order to prevent pancreatitis. However, it is not clear whether EST prevents pancreatitis or affects other adverse events (AEs). This study is conducted to evaluate the necessity of EST before FCSEMS placement for distal malignant biliary strictures due to a pancreatic head tumor.

Methods

This study included 68 patients who underwent FCSEMS placement for distal malignant biliary stricture due to a pancreatic head tumor. Treatment outcomes and AEs were retrospectively compared between 32 patients with EST before FCSEMS placement (EST group) and 36 patients without EST (non-EST group).

Results

The success rates of drainage for the EST and non-EST groups were 100% and 97.2%, respectively (P = 0.95). The incidence of pancreatitis in the EST and non-EST groups was 3.1% and 0%, respectively (P = 0.95). The incidence of hyperamylasemia in the EST and non-EST groups was 12.5% and 13.9%, respectively (P = 0.85). The incidence of all AEs in the EST and non-EST groups was 15.6% (pancreatitis: 1, cholecystitis: 2, and stent migration: 2) and 13.9% (cholecystitis: 3, stent migration: 2), respectively (P = 0.89).

Conclusions

EST before FCSEMS placement for distal malignant biliary stricture due to a pancreatic head tumor does not affect the successful drainage and incidence of adverse events. The necessity of EST to prevent pancreatitis before FCSEMS placement was deemed low.