Inside Plastic Stents versus Metal Stents for Treating Unresectable Malignant Perihilar Biliary Obstructions: A Retrospective Comparative Study

Development and application of an early warning model for predicting early mortality following stent placement in malignant biliary obstruction: A comparative analysis of logistic regression and artificial neural network approaches

Patients with malignant biliary obstruction (MBO) are often treated with endoscopic retrograde cholangiopancreatography (ERCP) combined with biliary stent placement for tumor progression. However, certain patients die within 30 days after the procedure, increasing healthcare resource consumption and patient burden. Therefore, the development of early mortality prediction models is important for optimizing treatment decisions. The present study retrospectively analyzed the clinical data of 285 patients with MBO, including demographic information, laboratory indicators and tumor-related factors. Logistic regression and artificial neural network (ANN) models were used to construct a prediction tool, and the model performance was evaluated using area under the curve (AUC), accuracy, sensitivity and specificity. The logistic regression model, which identified the cancer antigen 19-9 (CA19-9) level and a history of previous ERCP surgery as independent risk factors, had an AUC of 0.727 and an accuracy of 65.0%. The ANN model, which combined five variables, namely CA19-9, history of previous ERCP surgery, neutrophil-lymphocyte ratio (NLR), liver metastasis and carcinoembryonic antigen, demonstrated that NLR was the most weighted predictor. Furthermore, the ANN model had an AUC of 0.813, an accuracy of 88.2% and a specificity that was markedly higher than that of the logistic regression model (95.5 vs. 83.3%). However, the ANN model was revealed to be slightly less sensitive compared with the logistic regression model (61.1 vs. 61.2%). In conclusion, compared with logistic regression, the ANN model had a greater performance level in terms of predictive power and specificity, and is suitable for capturing complex non-linear relationships. However, its complexity and risk of overfitting need to be further optimized. The present study provides a new tool for the accurate prediction of the risk of early death after ERCP in patients with MBO, which could help improve individualized treatment strategies.

Evaluating safety and efficacy of plastic versus metal stenting in malignant hilar biliary obstruction: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Stenting malignant hilar biliary obstruction (MHBO) is challenging due to its complex structure, and it is less effective than blockages in the distal bile duct area. Plastic stents (PSs) and metal stents (MSs) are commonly used for stenting MHBO. This study aims to compare the outcomes of PSs and MSs in MHBO patients.

METHODS

We conducted a search of medical databases up to March 2024. Using a fixed-effect model, we analyzed the risk ratios (RRs) of the outcomes between the PS and MS groups. We calculated the RR for clinical and technical success, reinterventions, and adverse events, as well as the hazard ratio (HR) for survival and stent patency.

RESULTS

This analysis includes five randomized controlled trials (RCTs) that met the inclusion criteria, comprising a total of 322 patients (156 in the PS group and 166 in the MS group). Significant differences (P < .05) in favor of the MS group were found in the reinterventions (RR 1.80, 95% CI 1.07-3.04), and stent patency (HR 0.54, 95% CI 0.32-0.90). There were no significant differences (P > 0.05) between the PS and MS groups regarding technical success (RR 1.01, 95% CI 0.94-1.09), clinical success (RR 0.86, 95% CI 0.69-1.07), overall survival (HR 0.71, 95% CI 0.47-1.05), stent migration (RR 0.69, 95% CI 0.08-6.02), stent occlusion (RR1.32, 95% CI 0.97-1.81), and adverse events (RR 0.80, 95% CI 0.53-1.20).

CONCLUSION

Both PS and MS are effective for managing MHBO, while MS offers greater efficacy in increased stent patency and lower reintervention rates. Key message What is already known on this topic Metal stents (MSs) and plastic stents (PSs) are used for palliative treatment of malignant hilar biliary obstruction (MHBO). MSs significantly reduced the need for reinterventions compared to PSs in patients with MHBO. What this study adds There were no significant differences between MSs and PSs in terms of technical success, clinical success, overall survival, stent migration, stent occlusion, or adverse events. How this study might affect research, practice, or policy The study's findings may prompt researchers to design more targeted studies to further investigate these specific outcomes in MHBO patients. The results encourage endoscopists to consider patient-specific factors, such as life expectancy and preference for minimizing recurrent procedures, when choosing between MSs and PSs for MHBO.

Unilateral drainage and chemotherapy prolong the patency of a plastic stent placed above the sphincter of Oddi in patients with malignant hilar biliary obstruction

OBJECTIVES

To evaluate the results of inside stent therapy for unresectable malignant hilar biliary obstruction and identify factors related to stent patency duration.

METHODS

Of 44 patients who underwent initial inside-stent placement above the sphincter of Oddi from April 2017 to December 2022, 42 with the resolution of jaundice (clinical success rate, 95.5%) were retrospectively analyzed. Univariate and multivariate logistic regression analysis identified factors associated with stent patency duration.

RESULTS

Univariate analysis revealed significant differences in the drainage method (406 days for unilateral drainage vs. 305 days for bilateral drainage of the right and left liver lobes, p = 0.022) with or without chemotherapy (406 days with vs. 154 days without, p = 0.038). Multivariate analysis (Cox proportional hazards analysis) revealed similar results, with unilateral drainage (p = 0.031) and chemotherapy (p = 0.048) identified as independent factors associated with prolonged stent patency. Early adverse events were observed in two patients (4.8%; one cholangitis, one pancreatitis).

CONCLUSIONS

Inside-stent therapy was safely performed in patients with malignant hilar biliary obstruction. Simple unilateral drainage and chemotherapy may prolong stent patency.

Current status of preoperative endoscopic biliary drainage for distal and hilar biliary obstruction

The purpose of preoperative biliary drainage (PBD) is to reduce complications during the perioperative period. The extrahepatic bile duct comprises distal and hilar bile ducts and assessing the need for PBD must be considered separately for each duct, as surgical procedures and morbidities vary. The representative disease-causing distal bile duct obstruction is pancreatic cancer. A randomized controlled trial has revealed that PBD carries the risk of recurrent cholangitis and pancreatitis before surgery, thus eliminating the need for PBD when early surgery is feasible. However, neoadjuvant therapy has seen a rise in recent years, resulting in longer preoperative waiting periods and an increased demand for PBD. In such cases, metal stents are preferable to plastic stents due to their lower stent occlusion rates. When endoscopic transpapillary biliary drainage (EBD) is not viable, endoscopic ultrasound-guided biliary drainage may be a suitable substitute. In the hilar bile duct, the representative disease-causing obstruction is hilar cholangiocarcinoma. PBD's necessity has long been a subject of contention. In spite of earlier criticisms of routine PBD, recent views have emerged recommending PBD, particularly when major hepatectomy is required, to prevent postoperative liver failure. Given the risk of tumor seeding associated with percutaneous transhepatic biliary drainage, EBD is preferable. Nevertheless, as its shortcomings involve recurrent cholangitis until surgery due to stent or tube obstruction, it is necessary to seek out novel approaches to circumvent complications. In this review we summarize the current evidence for PBD in patients with distal and hilar biliary obstruction.

Safety and efficacy of biliary suprapapillary metal and plastic stents in malignant biliary obstruction: a systematic review and meta-analysis

BACKGROUND AND AIMS

Biliary drainage is vital in managing malignant biliary obstruction (MBO). Suprapapillary stenting has emerged as a viable alternative to transpapillary stenting and is performed using inside plastic (iPS) or metal stents (iMS). This meta-analysis aims to evaluate the outcomes of suprapapillary stent placement for MBO.

METHODS

The Embase, PubMed, and Web of Science databases were systematically searched to include all studies published before September 31, 2023, that reported on the outcomes of suprapapillary stents placed for MBO. Using the random-effect model, the pooled, weight-adjusted event rate estimate for the clinical outcomes was calculated with 95% confidence intervals (CIs).

RESULTS

Twenty-eight studies were included, with a total of 1401 patients. The pooled clinical success rate was 98.9%. A subgroup analysis yielded non-significant differences between the iPS and iMS groups (99.3% vs. 98.6%, respectively; P = 0.44). The pooled incidence rate of adverse events (AE) with suprapapillary stents was 9.5%. In a subgroup analysis, the incidence of AEs with iPS was 10.7% compared to 9% in the iMS group without a statistical difference (P = 0.32). The most common adverse event was cholangitis (2.2%), followed by pancreatitis (1.1%), cholecystitis (0.5%), and bleeding (0.12%).

CONCLUSION

When technically feasible, suprapapillary stenting for MBO is a viable endoscopic option with a high clinical success rate and acceptable adverse event rates. Both iPS and iMS exhibit similar efficacy.

Biliary drainage in hilar and perihilar cholangiocarcinoma: 25-year experience at a tertiary cancer center

BACKGROUND AND AIMS

This study analyzed the optimal biliary stenting strategy for palliation in cholangiocarcinoma (CCA).

METHODS

This was a retrospective study of patients with CCA who underwent biliary drainage from 1997 to 2023. A per-patient analysis of percutaneous transhepatic biliary drainage (PTBD) rates, the median number of ERCPs, and overall survival (OS) and a per-procedure analysis of clinical success (CS), stent-specific adverse events (AEs), and mean time to repeat ERCP by stent type and laterality (unilateral and bilateral) are presented.

RESULTS

A total of 333 patients underwent 1050 ERCPs, 85% with plastic stents (PSs). PTBD was eventually done in 23% of PS patients, 35% of whom had their PS removed before PTBD. ERCPs with the use of self-expandable metal stents (SEMSs)/unilateral SEMSs had higher CS (89%/91%) versus PSs/unilateral plastic stents (uPSs) (85% both) and PSs within SEMSs (PS-SEMSs)/uPS-SEMSs (71%/74%; P = .013/P = .054). Compared with PSs, SEMSs and PS-SEMSs were associated with higher stent-specific AEs (odds ratios [ORs]: SEMSs 4.85 [95% confidence interval (CI), 3.23-7.27], PS-SEMSs 9.99 [95% CI, 5.33-18.71]; P < .001). Straight PSs were associated with more stent-specific AEs compared with double-pigtail stents (OR 6.74 [95% CI, 3.95-11.45]; P < .001). More 7F stents were used in cases with balloon dilation (BD) (109 with BD vs 88 without BD; P < .001). BD had a 79% CS rate versus 87% without BD (P < .001). Cases with pus on ERCP and those with BD had a shorter mean time to repeat ERCP. On regression analyses, higher Bismuth class, PS use, and PS-SEMS use were associated with a shorter mean time to repeat ERCP. Fifty-two percent of patients in the bilateral SEMS arm died from cholangitis (P = .005).

CONCLUSIONS

The relatively higher CS rate of SEMSs is countered by the higher stent-specific AE rate. PSs can be removed and may better facilitate PTBD. Within PS types, double-pigtail stents may have fewer stent-specific AEs. Cases requiring BD and with endoscopic evidence of pus may benefit from earlier reintervention.

Endoscopic nasobiliary drainage versus endoscopic biliary stenting for preoperative biliary drainage in patients with malignant hilar biliary obstruction: Propensity score-matched multicenter comparative study

OBJECTIVES

For preoperative biliary drainage (PBD) of malignant hilar biliary obstruction (MHBO), current guidelines recommend endoscopic nasobiliary drainage (ENBD) due to the higher risk of cholangitis after endoscopic biliary stenting (EBS) during the waiting period before surgery. However, few studies have supported this finding. Therefore, we aimed to compare the outcomes of preoperative ENBD and EBS in patients with MHBO.

METHODS

Patients with MHBO who underwent laparotomy for radical surgery after ENBD or EBS were included from retrospectively collected data from 13 centers (January 2014 to December 2018). We performed a 1:1 propensity score matching between the ENBD and EBS groups. These patients were compared for the following: cholangitis and all adverse events (AEs) after endoscopic biliary drainage (EBD) until surgery, time to cholangitis development after EBD, postsurgical AEs, and in-hospital death after surgery.

RESULTS

Of the 414 patients identified, 355 were analyzed in this study (226 for ENBD and 129 for EBS). The matched cohort included 63 patients from each group. The proportion of cholangitis after EBD was similar between the two groups (20.6% vs. 25.4%, P = 0.67), and no significant difference was observed in the time to cholangitis development. The proportions of surgical site infections, bile leaks, and in-hospital mortality rates were similar between the groups.

CONCLUSION

For PBD of MHBO, the proportion of AEs, including cholangitis, after EBD until surgery was similar when either ENBD or EBS was used.

Comparison of unilateral and bilateral intraductal plastic stent placement for unresectable malignant hilar biliary obstruction: A propensity score-matched cohort analysis

BACKGROUND

Although intraductal plastic stent (IS) placement is an effective treatment for unresectable malignant hilar biliary obstruction (UMHBO), the effectiveness of unilateral and bilateral IS drainage remains controversial. This retrospective study investigated the effectiveness of bilateral IS placement for UMHBO using the propensity score matching method.

METHODS

Patients who underwent transpapillary endoscopic stenting for UMHBO were analyzed for technical and clinical success, adverse events, and time to recurrent biliary obstruction (TRBO).

RESULTS

A total of 321 patients were enrolled in the study with 27 patients in each unilateral and bilateral IS group in the propensity score-based cohort. Technical success was 100%, while clinical success was 93% and 96% in the unilateral and bilateral IS groups, respectively (p = 1.0). Cholecystitis occurred in 4% and 7%, respectively (p = 1.0). The median TRBO was shorter in the unilateral group (129 [5-383] days) than that in the bilateral group (226 [16-563] days) (p = .0281). Bilateral IS placement was an independent long TRBO factor (hazard ratio [HR] 0.46; 95% confidence interval [CI]: 0.21-0.97; p = .041).

CONCLUSIONS

Unilateral and bilateral IS placement had high technical and clinical success rates in primary stent placement. However, bilateral IS placement showed a longer TRBO. Bilateral IS placement may be a good option for initial UMHBO drainage.

A Novel Method of Calculating the Drained Liver Volume Using a 3D Volume Analyzer for Biliary Drainage of Unresectable Malignant Hilar Biliary Obstruction

OBJECTIVES

In patients with unresectable malignant hilar biliary obstruction (UMHBO), drainage of ≥ 50% liver volume correlates with better clinical outcomes. Accurately measuring the liver volume to be drained by biliary stents is required. We aimed to develop a novel method for calculating the drained liver volume (DLV) using a 3D volume analyzer (3D volumetry), and assess the usefulness for drainage in patients with UMHBO.

METHODS

Three-dimensional volumetry comprises the following steps: (1) manual tracing of bile duct using 3D imaging system; (2) 3D reconstruction of bile duct and liver parenchyma; and (3) calculating DLV according to the 3D distribution of bile ducts. Using 3D volumetry, we reviewed data of patients who underwent biliary drainage for UMHBO, calculated the DLV, and determined the association between DLV and biliary drainage outcome.

RESULTS

There were 104 eligible cases. The mean DLV was 708 ± 393 ml (53% ± 21%). and 65 patients (63%) underwent drainage of   ≥50% liver volume. The clinical success rate was significantly higher in patients with DLV ≥ 50% than in patients with DLV < 50% (89% vs. 28%, P < 0.001). The median time to recurrence of biliary obstruction (TRBO) and survival time were significantly longer in patients with DLV ≥ 50% than in patients with DLV < 50% (TRBO, 292 vs. 119 days, P = 0.03; survival, 285 vs. 65days, P = 0.004, log-rank test, respectively).

CONCLUSIONS

Three-dimensional volumetry, a novel method to calculate DLV accurately according to bile duct distribution was useful for drainage in UMHBO patients.

Partial Stent-in-Stent Method with an Uncovered Self-Expandable Metallic Stent for Unresectable Malignant Hilar Bile Duct Obstruction

(1) Background: There is controversy regarding stent placement for unresectable malignant hilar biliary obstruction (UMHBO). We mainly use the partial stent-in-stent (PSIS) method with an uncovered self-expandable metallic stent (UCSEMS) based on the drainage area and patency period. In this study, we investigated the usefulness and safety of the PSIS method. (2) Methods: In total, 59 patients who underwent the PSIS method for UMHBO at our hospital were included in the study. The technical success rate, clinical success rate, time to recurrent biliary obstruction (TRBO) and overall survival (OS) from the first placement, factors affecting TRBO and OS, and early complications within 30 days after the procedure were evaluated retrospectively. (3) Results: The technical and clinical success rates were 100% and 96.6%, respectively, with a TRBO of 121 days [95% confidence interval: 82-231] and an OS of 194 days [95% confidence interval: 113-305] after the first placement. Early complications occurred in nine patients (15.3%), including five cases of cholangitis, three cases of pancreatitis, and one case of cholecystitis. (4) Conclusions: The PSIS method for UMHBO is safe and useful with high technical and clinical success rates.

Utility of bilateral intraductal plastic stent for malignant hilar biliary obstruction compared with bilateral self-expandable metal stent: a propensity score-matched cohort analysis

BACKGROUND AND AIMS

Intraductal plastic stent (IS) placement for unresectable malignant hilar biliary obstruction (UMHBO) is an effective option for biliary drainage. However, the effectiveness of bilateral IS placement compared with bilateral self-expandable metal stent (SEMS) placement remains unclear.

METHODS

Overall, 301 patients with UMHBO were enrolled; 38 patients underwent bilateral IS placement (IS group) and 38 patients underwent SEMS placement (SEMS group) in the propensity score-based cohort. Both groups were compared for technical and clinical success, adverse events (AEs), recurrent biliary obstruction (RBO), time to RBO (TRBO), overall survival (OS), and endoscopic reintervention (ERI).

RESULTS

No significant differences were observed between the groups regarding technical and clinical success, AEs and RBO occurrence rates, TRBO, or OS. The median initial endoscopic procedure time was significantly shorter in the IS group (23 vs 49 minutes, P < .01). ERI was performed on 20 and 19 patients in the IS and SEMS groups, respectively. The median ERI procedure time was significantly shorter in the IS group (22 vs 35 minutes, P = .04). Median TRBO after ERI with plastic stent placement tended to be longer in the IS group (306 vs 56 days, P = .068). A Cox multivariate analysis showed that the IS group was the significant related factor for TRBO after ERI (hazard ratio, .31; 95% confidence interval, .25-.82; P = .035).

CONCLUSIONS

Bilateral IS placement can reduce the duration of the endoscopic procedure and provide sufficient stent patency both initially and after ERI stent placement, and the stents are removable. Bilateral IS placement is considered a good option for initial UMHBO drainage. (Clinical trial registration number: UMIN000050546.).

Suprapapillary placement of plastic versus metal stents for malignant biliary hilar obstructions: a multicenter, randomized trial

BACKGROUND AND AIMS

The efficacy of the suprapapillary placement of inside plastic stents (iPSs) for unresectable malignant hilar biliary obstructions (MHOs) is unknown compared with that of uncovered inside metal stents (iMSs). This randomized controlled trial was designed to evaluate the outcomes of endoscopic placement of these stents for unresectable MHOs.

METHODS

This open-label, randomized study was conducted at 12 Japanese institutions. The enrolled patients with unresectable MHOs were allocated to iPS and iMS groups. The primary outcome was defined as the time to recurrent biliary obstruction in patients for whom the intervention was both technically and clinically successful.

RESULTS

Among 87 enrollments, 38 patients in the iPS group and 46 patients in the iMS group were analyzed. Technical success rates were 100% (38 of 38) and 96.6% (44 of 46), respectively (P = 1.00). After transferring 1 unsuccessful iMS-group patient to the iPS group (since iPSs were deployed), the clinical success rates were 90.0% (35 of 39) for the iPS group and 88.9% (40 of 45) for the iMS group from a per-protocol analysis (P = 1.00). Among the patients with clinical success, the median times to recurrent biliary obstruction were 250 (95% confidence interval, 85-415) and 361 (95% confidence interval, 107-615) days (log-rank test, P = .34). No differences were detected in rates of adverse events.

CONCLUSIONS

This Phase II randomized trial did not show any statistically significant difference in stent patency between suprapapillary plastic versus metal stents. Considering the potential advantages of plastic stents for malignant hilar obstruction, these findings suggest that suprapapillary plastic stents could be a viable alternative to metal stents for this condition.

Endoscopic retrograde stent drainage therapies for malignant biliary obstruction: the distal opening of stent location above or across the duodenal papilla? A systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the efficacy and safety of the method of placing the distal stent opening above the duodenal papilla (hereinafter referred to Above method) for endoscopic retrograde stent internal drainage in MBO patients.

METHODS

PubMed, Embase, Web of science and Cochrane databases were searched to identify clinical studies comparing the stent distal opening mounted above the papilla and across the papilla (hereinafter referred to Across method), Comparison indicators included stent patency, stent occlusion rate, clinical success rate, overall complication rate, postoperative cholangitis rate, and overall survival. Revman5.4 software was used for meta-analysis, funnel plot and publication bias and Egger's test were completed by Stata14.0 software.

RESULTS

A total of 11 clinical studies (8 case-control studies, 3 RCT studies) were included, with a total of 751 patients (318 cases in the Above group and 433 cases Across group). The overall patency of Above method was longer than that of Across method (HR = 0.60, 95%CI [0.46-0.78], p < 0.001). Subgroup analysis showed statistical difference using plastic stent (HR = 0.49, 95%CI [0.33,0.73], p < 0.001). Inversely, there didn't exist significant difference in which metal stent were adopted (HR= 0.74, 95%CI [0.46,1.18], p = 0.21). Similarly, there also without statistical difference between patients with plastic stent placed above the papilla and metal stent mounted Across the papilla (HR = 0.73, 95%CI [0.15,3.65], p = 0.70). Moreover, the overall complication rate of the Above method was lower than that of the Across method (OR = 0.48,95%CI [0.30,0.75], p = 0.002). On the contrary, the differences of stent occlusion rate (OR = 0.86,95%CI [0.51,1.44], p = 0.56), overall survival (HR = 0.90, 95%CI [0.71,1.13]), p = 0.36), the clinical success rate (OR = 1.30, 95%CI [0.52,3.24], p = 0.57) and postoperative cholangitis rats (OR = 0.73, 95%CI [0.34,1.56], p = 0.41) were not statistically significant.

CONCLUSIONS

The distal opening of the stent can be placed above the duodenal main papilla for eligible MBO patients who receiving endoscopic retrograde stent drainage treatment, which can effectively prolong the patency duration when plastic stent is used, and reduce the overall risk of complications.

Clinical Outcomes of Inside Stents and Conventional Plastic Stents as Bridge-to-Surgery Options for Malignant Hilar Biliary Obstruction

BACKGROUND

The appropriate method of preoperative endoscopic biliary drainage (EBD) for cholangiocarcinoma with hilar biliary obstruction remains controversial. The inside-stent technique is a method of placing plastic stents entirely inside the bile duct. Several studies of patients with unresectable stage have reported longer stent patency compared with conventional endoscopic biliary stenting (EBS). Inside-stent techniques have been introduced as a bridge-to-surgery option and as an alternative to conventional EBS.

AIMS

We aimed to evaluate the clinical outcomes of inside stent use and conventional EBS.

METHODS

During this retrospective multicenter study, we reviewed consecutive patients with cholangiocarcinoma who underwent radical surgery after conventional EBS or inside-stent insertion. Adverse event (AE) rates after EBD and post-surgical AEs were compared. A multivariable analysis was performed to identify factors affecting cholangitis after EBD.

RESULTS

Conventional EBS and inside-stent procedures were performed for 56 and 73 patients, respectively. Patient backgrounds were similar between groups, except for percutaneous transhepatic portal vein embolization. The waiting time before surgery was similar between groups (28.5 days vs. 30 days). There were no significant differences in the cholangitis rate (21.4% vs. 26.0%; P = 0.68) and all AEs (25.0% vs. 30.1%; P = 0.56) between groups. The post-surgical AE rate was similar between the groups. The multivariable analysis found that preprocedural cholangitis was a risk factor for cholangitis after EBD (odds ratio: 5.67; 95% confidence interval: 1.61-19.9).

CONCLUSIONS

The outcomes of inside-stent techniques and conventional EBS for the management of preoperative EBD are comparable for patients with cholangiocarcinoma.

Development of novel biliary metal stent with coil-spring structure and its application in vivo swine biliary stricture model

Background

As of date, endoscopic biliary stenting with plastic stent (PS) and self-expandable metal stent (SEMS) have been widely used for the palliation of biliary tract strictures. However, these two stents have several limitations regarding the management of biliary strictures caused by intrahepatic and hilar cholangiocarcinoma. PS has short patency and also risks bile duct injury and bowel perforation. SEMS is difficult to revise when occluded by tumor overgrowth. To compensate for such shortcomings, we developed a novel biliary metal stent with coil-spring structure. The aim of this study was to investigate the feasibility and efficacy of the novel stent in a swine model.

Methods

The biliary stricture model was prepared in six mini-pigs using endobiliary radiofrequency ablation. Conventional PS (n=2) and novel stents (n=4) were deployed endoscopically. Technical success was defined as successful stent placement and clinical success was defined as >50% reduction of serum bilirubin level. Adverse events, stent migration, and endoscopic removability for one month after stenting were also assessed.

Results

The biliary stricture was successfully created in all animals. The technical success rate was 100 %, and the clinical success rate was 50% in the PS group and 75% in the novel stent group. In the novel stent group, the median pre- and post-treatment serum bilirubin levels were 3.94 and 0.3 mg/dL. Stent migration occurred in two pigs and two stents were removed by endoscopy. There was no stent-related mortality.

Conclusions

The newly designed biliary metal stent was feasible and effective in a swine biliary stricture model. Further studies are needed to verify the usefulness of the novel stent in the management of biliary strictures.

The feasibility of percutaneous transhepatic gallbladder aspiration for acute cholecystitis after self-expandable metallic stent placement for malignant biliary obstruction: a 10-year retrospective analysis in a single center

BACKGROUND/AIMS

Patients with acute cholecystitis (AC) after metallic stent (MS) placement for malignant biliary obstruction (MBO) have a high surgical risk. We performed percutaneous transhepatic gallbladder aspiration (PTGBA) as the first treatment for AC. We aimed to identify the risk factors for AC after MS placement and the poor response factors of PTGBA.

METHODS

We enrolled 401 patients who underwent MS placement for MBO between April 2011 and March 2020. The incidence of AC was 10.7%. Of these 43 patients, 37 underwent PTGBA as the first treatment. The patients' responses to PTGBA were divided into good and poor response groups.

RESULTS

There were 20 patients in good response group and 17 patients in poor response group. Risk factors for cholecystitis after MS placement included cystic duct obstruction (p<0.001) and covered MS (p<0.001). Cystic duct obstruction (p=0.003) and uncovered MS (p=0.011) demonstrated significantly poor responses to PTGBA. Cystic duct obstruction is a risk factor for cholecystitis and poor response factor for PTGBA, whereas covered MS is a risk factor for cholecystitis and an uncovered MS is a poor response factor of PTGBA for cholecystitis.

CONCLUSION

The onset and poor response factors of AC after MS placement were different between covered and uncovered MS. PTGBA can be a viable option for AC after MS placement, especially in patients with covered MS.

Self-expandable metal stents have longer patency and less cholangitis than inside stents in malignant perihilar biliary obstruction

Background and Aim

Outcomes of an inside stent (IS, a plastic stent placed above the sphincter of Oddi) versusa self-expandable metal stent (SEMS) for the drainage of malignant perihilar biliary obstruction has not been fully studied. The drainage strategy for perihilar biliary obstruction is difficult and should be clarified.

Methods

Clinical data of patients who underwent biliary drainage for malignant perihilar biliary obstruction with IS or SEMS between April 2016 and September 2021 at our institution were retrospectively examined. Outcomes, including the time to recurrent biliary obstruction (TRBO), survival, and incidence of recurrent biliary obstruction with concomitant cholangitis (RBOC), were retrospectively evaluated.

Results

Median TRBO was 280 (95% confidence interval [CI], 110-not available) days in the SEMS group (n = 24) and 113 (95% CI, 74-192) days in the IS group (n = 25) (P = 0.043). Among the patients with perihilar cholangiocarcinoma, the median survival of the two groups was comparable, namely 330 days in the SEMS group and 359 days in the IS group (P = 0.46). The incidence of RBOC at re-intervention was significantly higher in patients with ISs (83.9%) than in those with SEMSs (0%) (P = 0.00004).

Conclusions

TRBO was significantly longer in the SEMS group. Regardless of whether SEMSs or ISs were placed during the first intervention, patient survival was similar. Using easily removable ISs first might be a reasonable option because TRBO with SEMSs was shorter than patient survival. Cholangitis is a problem associated with the placement of IS.

Recent advances regarding endoscopic biliary drainage for unresectable malignant hilar biliary obstruction

Biliary drainage for unresectable malignant hilar biliary obstruction (UMHBO) is still associated with a number of controversies to be resolved. The superiority of bilateral drainage in comparison to unilateral drainage has not been proven obviously yet. However, bilateral drainage is necessary to treat obstructive jaundice in some UMHBO patients, and this may be connected with preservation of the functional liver volume. The partial stent-in-stent (SIS) method and side-by-side (SBS) method developed as bilateral drainage methods. There is no significant difference in the technical or clinical success rates of the SIS and SBS methods. In addition, these methods are comparable in terms of adverse events, patency period, and survival period. On the other hand, reintervention for recurrent biliary obstruction (RBO) after the SBS method seems to be easier in comparison to cases with RBO after the SIS method; however, there is no remarkable difference in the clinical results of these procedures. Endoscopic ultrasound (EUS)-guided biliary drainage also has become an option for patients with UMHBO. Left hepatic drainage using EUS-guided hepaticogastrostomy (EUS-HGS) has become common; however, few studies have reported the results of bridging drainage for the right lobe using the EUS-HGS route or EUS-guided hepaticojejunostomy. A few studies addressed the results of newly designed stents, such as the 6-mm braided metal stent and inside stent. The development of various drainage methods and new devices is necessary for the further advancement of endoscopic biliary drainage for patients with UMHBO, further studies to evaluate those methods and devices are warranted.

Double-scope method is helpful to rescue a retrieval thread attached to a stent caught on the duodenoscope forceps elevator

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Endoscopic or percutaneous biliary drainage in hilar cholangiocarcinoma: When and how?

Hilar cholangiocarcinoma (hCCA) is a primary liver tumor associated with a dim prognosis. The role of preoperative and palliative biliary drainage has long been debated. The most common techniques are endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic biliary drainage (PTBD); however, recently developed endoscopic ultrasound-assisted methods are gaining more atention. Selecting the best available method in any specific scenario is crucial, yet sometimes challenging. Thus, this review aimed to discuss the available techniques, indications, perks, pitfalls, and timing-related issues in the management of hCCA. In a preoperative setting, PTBD appears to have some advantages: low risk of postprocedural complications (namely cholangitis) and better priming for surgery. For palliative purposes, we propose ERCP/PTBD depending on the experience of the operators, but also on other factors: the level of bilirubin (if very high, rather PTBD), length of the stenosis and the presence of cholangitis (PTBD), ERCP failure, or altered biliary anatomy.

Endoscopic or percutaneous biliary drainage in hilar cholangiocarcinoma: When and how?

Hilar cholangiocarcinoma (hCCA) is a primary liver tumor associated with a dim prognosis. The role of preoperative and palliative biliary drainage has long been debated. The most common techniques are endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic biliary drainage (PTBD); however, recently developed endoscopic ultrasound-assisted methods are gaining more atention. Selecting the best available method in any specific scenario is crucial, yet sometimes challenging. Thus, this review aimed to discuss the available techniques, indications, perks, pitfalls, and timing-related issues in the management of hCCA. In a preoperative setting, PTBD appears to have some advantages: low risk of postprocedural complications (namely cholangitis) and better priming for surgery. For palliative purposes, we propose ERCP/PTBD depending on the experience of the operators, but also on other factors: the level of bilirubin (if very high, rather PTBD), length of the stenosis and the presence of cholangitis (PTBD), ERCP failure, or altered biliary anatomy.

Editors' Choice of Noteworthy Clinical Endoscopy Publications in the First Decade

This is a special review to celebrate the 10th anniversary of Clinical Endoscopy. Each deputy editor has selected articles from one's subspecialty that are significant in terms of the number of downloads, citations, and clinical importance. The articles included original articles, review articles, systematic reviews, and meta-analyses.