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

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Retrospective comparative study of new slim-delivery and conventional large-cell stents for stent-in-stent methods for hilar malignant biliary obstruction

OBJECTIVES

Endoscopic management of unresectable hilar malignant biliary obstruction (HMBO) is technically challenging, and effectiveness of stent-in-stent using large-cell, metal stents was reported. A new, large-cell stent with a 6F tapered delivery system was recently developed. The aim of this study was to compare clinical outcomes of slim-delivery and conventional large-cell stents.

METHODS

This was a multicenter retrospective comparative study of stent-in-stent methods using slim-delivery stents (Niti-S Large Cell SR Slim Delivery [LC slim-delivery]) and conventional stents (Niti-S large-cell D-type; LCD) for unresectable HMBO.

RESULTS

Eighty-three patients with HMBO were included; 31 LC slim-delivery and 52 LCD. Overall technical and clinical success rates were 100% and 90% in LC slim-delivery group and 98% and 88% in LCD group. Use of the LC slim-delivery was associated with shorter stent placement time in the multiple regression analysis, with a stent placement time of 18 and 23 min in LC slim-delivery and LCD groups, respectively. The early adverse event (AE) rate of LC slim-delivery was 10%, with no cholangitis or cholecystitis as compared to 23% in the LCD group. Recurrent biliary obstruction (RBO) rates and time to RBO were comparable between the two groups: 35% and 44%, and 8.5 and 8.0 months in LC slim-delivery and LCD groups, respectively. The major cause of RBO was tumor ingrowth (82%) in the LC slim-delivery group and sludge (43%) and ingrowth (48%) in LCD group.

CONCLUSION

Stent-in-stent methods using LC slim-delivery shortened stent placement time with low early AE rates and comparable time to RBO in patients with HMBO.

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.

Skeletal muscle status and survival among patients with advanced biliary tract cancer

BACKGROUND

Studies have demonstrated a prognostic role of sarcopenia (i.e., loss of skeletal muscle volume and functionality) in patients with various cancer types. In patients with biliary tract cancer, the quantity and quality of skeletal muscles and their serial changes have not been fully investigated in relation to survival outcomes.

METHODS

We identified 386 patients with unresectable or recurrent biliary tract cancer and calculated skeletal muscle index (SMI) and skeletal muscle density (SMD) to estimate muscular quantity and quality, respectively, based on computed tomography images. Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) according to skeletal muscle status and its serial change.

RESULTS

Compared to patients without sarcopenia, patients with sarcopenia were associated with shorter PFS (multivariable HR, 1.60; 95% CI, 1.15-2.22; P = 0.005), but not with OS (P = 0.027) at the adjusted α level of 0.013. SMD at baseline was associated with OS (multivariable HR comparing the extreme quartiles, 1.52; 95% CI, 1.07-2.14; Ptrend = 0.012), but not with PFS (Ptrend = 0.13). A reduction in SMI rather than that in SMD was associated with OS. Progressive disease was a risk factor for reductions in SMI and SMD.

CONCLUSIONS

Skeletal muscle quantity and quality and their serial changes were associated with survival outcomes in patients with advanced biliary tract cancer. Our data highlight the importance of designing nutritional and physical interventions for improvements in skeletal muscle status.

Endoscopic Treatment of Malignant Hilar Biliary Obstruction

Stent implantation is an effective approach for palliative treatment of Bismuth-Corlette type III-IV malignant hilar biliary obstructions (MHBOs). In this article, we reviewed the currently used access methods for biliary stent placement (percutaneous transhepatic biliary drainage, endoscopic biliary drainage, endosonography guided biliary drainage), the available stent types (plastic stent, self-expanding metallic stent, full cover self-expanding metallic stent, radioactive self-expanding metallic stent), major approaches (unilateral, bilateral) and deployment methods (stent-in-stent, stent-by-stent). Finally, this review gives an outlook on perspectives of development in stenting and other palliative methods in MHBO.

Meta-analysis on clinical outcomes of suprapapillary versus transpapillary stent insertion in malignant biliary obstruction

BACKGROUND/AIMS

Endoscopic biliary stenting is an essential treatment for malignant biliary obstruction (MBO). However, the optimal location for the placement of metal stents (MS) or plastic stents (PS) during the management of MBO, whether above (suprapapillary) or across (transpapillary) the sphincter of Oddi (SO), has not been thoroughly evaluated. This meta-analysis aims to compare the clinical outcomes associated with endoscopic retrograde cholangiopancreatography (ERCP)-guided biliary stents placed above and across the SO in patients with MBO.

METHODS

A comprehensive search of electronic databases was carried out to identify studies published from inception to April 2022. The clinical outcomes examined including stent patency, stent occlusion, and overall adverse events (AEs) such as cholangitis, post-ERCP pancreatitis (PEP), cholecystitis, stent migration, and bleeding. The selection of a random-effects model or fixed-effects model was based on the presence of heterogeneity.

RESULTS

A total of 12 articles involving 751 patients were analyzed. The findings showed that the suprapapillary approach had longer stent patency compared to the transpapillary approach (mean difference: 38.58; 95% confidence interval 16.02-61.14, P < 0.0001). Additionally, the suprapapillary approach was associated with a lower risk of stent occlusion and overall AEs (P = 0.04, P = 0.002, respectively), particularly in the incidence of PEP (P = 0.009). The incidence of cholangitis, cholecystitis, stent migration, and bleeding were similar between the suprapapillary and transpapillary approaches. The subgroup analyses indicated that suprapillary PS had a significant decrease in the incidence of stent occlusion and longer stent patency, while suprapillary MS had a significant decrease in the incidence of overall AEs and PEP than the transpapillary approach.

CONCLUSION

Compared with the transpapillary approach, the suprapapillary stent had superiority in longer stent patency, lower rates of stent occlusion and overall AEs, and notably, a lower incidence of PEP. The incidence of cholangitis, cholecystitis, stent migration, and bleeding were similar between the suprapapillary and transpapillary approaches. Further large-scale randomized controlled studies are needed to confirm our findings.

REGISTRATION NO

CRD42022336435.

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.

Endoscopic Transpapillary Stenting for Malignant Hilar Biliary Stricture: Side-by-Side Placement versus Partial Stent-in-Stent Placement

BACKGROUND/AIMS

Endoscopic uncovered metal stent (UMS) placement has been widely performed for unresectable hilar malignant biliary stricture (UHMBS). Two stenting methods are used for the two bile duct branches: side-by-side placement (SBS) and partial stent-in-stent placement (PSIS). However, it remains controversial whether SBS or PSIS is superior. This study aimed to compare SBS and PSIS in UHMBS cases with UMS placement in two branches of the IHD.

METHODS

This retrospective study included 89 cases of UHMBS treated with UMS placement through the SBS or PSIS technique using endoscopic retrograde cholangiopancreatography at our institution. Patients were divided into two groups, SBS (n = 64) and PSIS (n = 25), and compared.

RESULTS

Clinical success was achieved in 79.7% and 80.0% in the SBS and PSIS groups, respectively (p = 0.97). The adverse event rate was 20.3% and 12.0% in the SBS and PSIS groups, respectively (p = 0.36). The recurrent biliary obstruction (RBO) rate was 32.8% and 28.0% in the SBS and PSIS groups, respectively (p = 0.66). The median cumulative time to RBO was 224 and 178 days in the SBS and PSIS groups, respectively (p = 0.52). The median procedure time was 43 and 62 min in the SBS and PSIS groups, respectively, which was significantly longer in the PSIS group (p = 0.014).

CONCLUSIONS

No significant differences were noted in the clinical success rate, adverse event rate, time to RBO, or overall survival between the SBS and PSIS groups, other than the significantly longer procedure time in the PSIS group.

Comparison of the hybrid and partial stent-in-stent method for endoscopic three-segment drainage for unresectable malignant hilar biliary obstruction

Background and study aims  The clinical outcome of the new hybrid drainage method for unresectable malignant hilar biliary obstruction (UMHBO) has not yet been compared with that of the partial stent-in-stent (PSIS) method with three or more stents.

Patients and methods  Patients with UMHBO underwent drainage of three segments using the hybrid or PSIS method. The clinical outcomes of both methods were compared retrospectively.

Results  Overall, 54 patients underwent the hybrid (n = 31) or PSIS (n = 23) method of drainage with three or more stents for UMHBO. There were no significant differences in the technical success rate (hybrid vs. PSIS, 87.1 % vs. 87 %), clinical success rate according to per-protocol analysis (81.5 % vs. 70 %), early adverse events rate (14.8 % vs. 10%), late adverse events rate (7.4 % vs. 0 %), and technical success rate of the endoscopic transpapillary reintervention (90.9 % vs. 100 %). Time to recurrent biliary obstruction (TRBO) of the hybrid and PSIS methods was 178 and 231 days, respectively, with no significant difference ( P  = 0.354).

Conclusions  The choice between the two methods should be made at the physician’s discretion.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Success, complication, and mortality rates of initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma

BACKGROUND

The patients with unresectable perihilar cholangiocarcinoma require biliary drainage to relieve symptoms and allow for palliative systemic chemotherapy. The aim of this study was to establish the success, complication, and mortality rates of the initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma at presentation.

METHODS

In this retrospective multicenter study, patients with unresectable perihilar cholangiocarcinoma who underwent initial endoscopic or percutaneous transhepatic biliary drainage between 2002 and 2014 were included. The success of drainage was defined as a successful biliary stent or drain placement, no unscheduled reintervention within 14 days, and serum bilirubin levels <50 μmol/L (ie, 2.9 mg/dL) or a >50% decrease in serum bilirubin after 14 days. Severe complications, and 90-day mortality were recorded.

RESULTS

Included were 186 patients: 161 (87%) underwent initial endoscopic biliary drainage and 25 (13%) underwent initial percutaneous transhepatic biliary drainage. The success of initial drainage was observed in 73 patients (45%) after endoscopic biliary drainage and 6 (24%) after percutaneous transhepatic biliary drainage. The reasons for an unsuccessful initial drainage were: the failure to place a drain or stent in 39 patients (21%), an unplanned reintervention within 14 days in 52 patients (28%), and the bilirubin level >50 μmol/L (or not halved) after 14 days of initial drainage in 16 patients (9%). Severe drainage-related complications occurred in 19 patients (12%) after endoscopic biliary drainage and in 3 (12%) after percutaneous transhepatic biliary drainage. Overall, 66 patients (36%) died within 90 days after initial biliary drainage.

CONCLUSION

Initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma had a success rate of 45% and a 90-day mortality rate of 36%. Future studies for patients with perihilar cholangiocarcinoma should focus on improving biliary drainage.

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.

Endoscopic palliation of malignant biliary obstruction

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

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.

Role of ERCP in Malignant Hilar Biliary Obstruction

Malignant hilar biliary obstruction (MHO), an aggressive perihilar biliary obstruction caused by cholangiocarcinoma, gallbladder cancer, or other metastatic malignancies, has a poor prognosis. Surgical resection is the only curative treatment method for biliary malignancies. However, most of the patients with MHO cannot undergo surgeries on presentation because of an advanced inoperable state or a poor performance state due to old age or comorbid diseases. Therefore, palliative biliary drainage is mandatory to improve symptomatic jaundice and quality of life. Among drainage methods, endoscopic biliary drainage is the current standard for the palliation of unresectable advanced MHO. The development of stents and various accessories and advances in endoscopic techniques including endoscopic ultrasonography have facilitated primary endoscopic intervention in difficult high-grade hilar strictures. However, some issues are still under debate, such as palliation methods, appropriate stents, the number of stents, deployment methods, and additional local ablation therapies. Therefore, this review presents currently optimal endoscopic palliation methods for advanced MHO based on the reported literature.

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.

Endoscopic Bilateral Stent-in-Stent Versus Stent-by-Stent Deployment in Advanced Malignant Hilar Obstruction: A Meta-Analysis and Systematic Review

BACKGROUND AND AIM

There is no clear data to compare the effectiveness and safety of bilateral stent-in-stent (SIS) or stent-by-stent (SBS) deployment for advanced malignant hilar obstruction (MHO). This meta-analysis was done to investigate clinical outcomes of these deployment methods.

METHODS

We did a literature search to identify studies that reported the clinical outcomes of bilateral metal stents in patients with advanced MHO. Weighed pooled rates (WPR) along with 95% confidence interval (95% CI) were calculated in order to compare outcomes including technical and clinical success, adverse events, and stent occlusion between the two groups. We conducted a meta-analysis using a random-effects model.

RESULTS

Five comparative studies with 250 patients, and 20 single-arm studies for the SIS or SBS method were eligible for the meta-analysis and systematic review. The bilateral SIS deployment had a significantly higher technical success rate than did SBS deployment (OR 6.43; 95% CI 1.08-38.09). There was no difference in the clinical success (OR 1.23; 95% CI 0.45-3.38), overall adverse events rates (OR 0.42; 95% CI 0.15-1.18), or overall occlusion rate (OR 1.55; 95% CI 0.89-2.70). As a single-armed group, WPR of technical success of the SIS and SBS groups was 96.4% and 89.6%, respectively. Clinical success was 97.5% and 98.3%. Overall, adverse events were 35.9% and 22.6%. Occlusion rates were 27.7% and 37.7%.

CONCLUSIONS

Although there was a lack of quality data and heterogeneity, bilateral SIS deployment had a higher technical feasibility than did the SBS method in patients with advanced MHO, without differences in terms of clinical success, adverse events, or occlusion rates.

Possible reasons for the regrettable results of patency of an inside stent in endoscopic transpapillary biliary stenting

Endoscopic biliary decompression is a minimally invasive procedure for cholestasis since the first endoscopic retrograde cholangiopancreatography-guided biliary stenting performed by Soehendra and Reynders-Frederix. Among the endoscopic biliary decompression, endoscopic transpapillary biliary stenting (EBS), is a mainstream choice and presently has two methods of placement: stenting above the sphincter of Oddi (SO) (suprapapillary) and stenting across the SO (transpapillary). Stent patency is the most important concern for patients, endoscopists and physicians because it can affect both the life prognosis and treatment schedule of patients. Biliary stent occlusion can occur because of several factors. Among them, direct food impaction, biofilm formation, and sludge formation play important roles and are presumed to be theoretically overcome by EBS above the SO. Thus, EBS above the SO is expected to result in a longer patency than EBS across the SO. In the literature, there have been six comparative studies on EBS for distal biliary obstruction in which the stent was placed above or across the SO, including two randomized controlled trials (RCTs) with negative results of stenting above the SO. With respect to EBS for hilar biliary obstruction, there have been no RCTs, whereas four retrospective comparative studies with negative results and four retrospective comparative studies showing positive results of stenting above the SO have been reported. In this review, we focused on EBS above and across the SO, and summarized the positive and negative results of the two types of stenting to promote effective clinical practice and to provide a basis for future studies.

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.

Percutaneous stent-in-stent placement with large cell-type stents for malignant hilar biliary obstruction

BACKGROUND

To overcome the technical difficulty of bilateral stent-in-stent placement, large cell-type biliary stents have been developed. However, most of the studies using large cell-type stents were conducted with endoscopic method.

PURPOSE

To evaluate the efficacy and safety of percutaneous stent placement with a stent-in-stent method using large cell-type stents in patients with malignant hilar biliary obstruction.

MATERIAL AND METHODS

From December 2015 and October 2018, 51 patients with malignant hilar biliary obstruction were retrospectively studied. All of the patients underwent bilateral (n=46) or unilateral (n=5) stenting in a T, Y, or X configuration with a stent-in-stent method using large cell-type stents. Technical success, complications, successful internal drainage, stent patency, and patient survival were analyzed.

RESULTS

A total of 118 stents were successfully placed in 51 patients (100.0%). Three patients had minor complications with self-limiting hemobilia. Major complications were not observed in any patient. Successful internal drainage was achieved in 45 patients (88.2%). Clinical follow-up information until death or the end of the study was available for 50 of 51 patients. The median patient survival was 285.5 days (95% confidence interval [CI] 197-374). Stent dysfunction occurred in 16 patients (35.6%) due to tumor ingrowth (n=9) or tumor ingrowth combined with biliary sludge (n=7) among the patients who achieved successful internal drainage. Median stent patency was 179 days (95% CI 104-271).

CONCLUSION

Percutaneous stent-in-stent placement with large cell-type stents is technically feasible and safe, and can be an effective technique in patients with malignant hilar biliary obstruction.

Multi-center study of endoscopic revision after side-by-side metal stent placement for malignant hilar biliary obstruction

BACKGROUND

The recent development of ultra-thin delivery systems, which enable simultaneous insertion of two metal stents, has encouraged wider adoption of side-by-side (SBS) stent placement for malignant hilar biliary obstruction (MHBO). However, the management of stent occlusion after SBS placement has not been well-characterized. This study aimed to examine the outcomes of endoscopic reintervention (E-RI) after SBS placement in patients with MHBO.

METHODS

Sixty-seven patients who underwent E-RI for stent occlusion after SBS placement between 2013 and 2020 at three tertiary-care referral centers were investigated. We evaluated the technical success, clinical success, recurrent biliary obstruction (RBO), and adverse events other than RBO rates associated with E-RI. Furthermore, the factors associated with successful E-RI were also evaluated.

RESULTS

The technical success and clinical success rates were 79.1% (53/67) and 76.1% (51/67), respectively. Early adverse events other than RBO occurred in 4.5% (3/67) and late events in 3.9% (2/51). The RBO rate after E-RI was 52.9% (27/51), and the median time to RBO after E-RI was 85 days. Common bile duct (CBD) diameter (odds ratio 2.62; 95% confidence interval, 1.37-5.01; P = 0.003) and metastatic disease (odds ratio, 0.11; 95% confidence interval, 0.02-0.64; P = 0.015) were independently correlated with E-RI success in the multivariate analysis.

CONCLUSIONS

This study demonstrated that E-RI after SBS placement is technically feasible and safe, but the success rate was significantly lower in patients with narrow CBDs and metastatic diseases. These factors may be useful for the selection of the initial stenting method.

A Prospective Multicenter Study of "Inside Stents" for Biliary Stricture: Multicenter Evolving Inside Stent Registry (MEISteR)

Background: Endoscopic biliary stent placement is the standard of care for biliary strictures, but stents across the papilla are prone to duodenobiliary reflux, which can cause stent occlusion. Preliminary studies of “inside stents” placed above the papilla showed encouraging outcomes, but prospective data with a large cohort were not reported. Methods: This was a prospective multicenter registry of commercially available inside stents for benign and malignant biliary strictures. Primary endpoint was recurrent biliary obstruction (RBO). Secondary endpoints were technical success of stent placement and removal, adverse events, and stricture resolution. Results: A total of 209 inside stents were placed in 132 (51 benign and 81 malignant) cases with biliary strictures in 10 Japanese centers. During the follow-up period of 8.4 months, RBO was observed in 19% of benign strictures. The RBO rate was 49% in malignant strictures, with the median time to RBO of 4.7 months. Technical success rates of stent placement and removal were both 100%. The adverse event rate was 8%. Conclusion: This prospective multicenter study demonstrated that inside stents above the papilla were feasible in malignant and benign biliary strictures, but a randomized controlled trial is warranted to confirm its superiority to conventional stents across the papilla.

Endoscopic retrograde cholangiopancreatography drainage for palliation of malignant hilar biliary obstruction — stent-in-stent or side-by-side? A systematic review and meta-analysis

BACKGROUND

Biliary drainage, either by the stent-in-stent (SIS) or side-by-side (SBS) technique, is often required when treating a malignant hilar biliary obstruction (MHBO). Both methods differ from each other and have distinct advantages.

AIM

To compare both techniques regarding their efficacy and safety in achieving drainage of MHBO.

METHODS

A comprehensive search of multiple electronic databases (MEDLINE, Embase, LILACS, BIREME, Cochrane) was conducted and grey literature from their inception until December 2020 with no restrictions regarding the year of publication or language, since there was at least an abstract in English. The included studies compared SIS and SBS techniques through endoscopic retrograde cholangiopancreatography. Outcomes analyzed included technical and clinical success, early and late adverse events (AEs), stent patency, reintervention, and procedure-related mortality.

RESULTS

Four cohort studies and one randomized controlled trial evaluating a total of 250 patients (127 in the SIS group and 123 in the SBS group) were included in this study. There were no statistically significant differences between the two groups concerning the evaluated outcomes, except for stent patency, which was higher in the SIS compared with the SBS technique [mean difference (d) = 33.31; 95% confidence interval: 9.73 to 56.90, I² = 45%, P = 0.006].

CONCLUSION

The SIS method showed superior stent patency when compared to SBS for achieving bilateral drainage in MHBO. Both techniques are equivalent in terms of technical success, clinical success, rates of both early and late AEs, reintervention, and procedure-related mortality.

Bilateral stenting for hilar biliary obstruction: a meta-analysis of side-by-side versus stent-in-stent

PURPOSE

To evaluate the efficacy of stent-in-stent (SIS) and side-by-side (SBS) bilateral stenting for treating malignant hilar biliary obstruction (MHBO).

MATERIAL AND METHODS

Relevant studies in Pubmed, Embase, and Cochrane Library were identified through June 2020. This meta-analysis was conducted using RevMan v5.3, using relevant endpoint data relating to clinical and technical success, complications, stent dysfunction, and overall survival (OS) rates extracted from these studies.

RESULTS

We identified six relevant studies which included 315 MHBO patients treated with either SBS (n = 161) or SIS bilateral (n = 154) stenting. We saw no significant difference between these two groups with respect to clinical success (OR: 1.07; 95% CI: 0.46, 2.49, p = .87), complication (HR: 0.12; 95% CI: -0.04, 0.27, p = .15), stent dysfunction (OR: 0.68; 95% CI: 0.42, 1.10, p = .11), or OS (HR: 0.97; 95% CI: 0.82, 1.16, p = .74). However, the SBS group exhibited significantly lower technical success rates (OR: 6.55; 95% CI: 1.10, 38.83, p = .04). Significant heterogeneity was only detected for the endpoint of complication rates (I² = 60%).

CONCLUSION

These results suggest that SIS bilateral stenting yields better rates of technical success than does SBS bilateral stenting in MHBO patients.

Unilateral versus Bilateral Endoscopic Nasobiliary Drainage and Subsequent Metal Stent Placement for Unresectable Malignant Hilar Obstruction: A Multicenter Randomized Controlled Trial

(1) Background: Endoscopic management of hilar biliary obstruction is still challenging. Compared with unilateral drainage, bilateral drainage could preserve larger functional liver volume and potentially improve clinical outcomes. To evaluate the effectiveness of bilateral drainage, we conducted this multicenter randomized controlled study. (2) Methods: Patients with unresectable malignant hilar biliary obstruction were assigned to unilateral or bilateral group. At first, patients underwent endoscopic nasobiliary drainage (ENBD), and subsequently underwent self-expandable metallic stent (SEMS) deployment. Primary outcomes were the functional success rate of ENBD and time to recurrent biliary obstruction (TRBO) after SEMS deployment. (3) Results: During the study period, 38 and 39 patients were enrolled in the unilateral and bilateral groups. The functional success rate was similar in the uni- and bi-ENBD group (57% vs. 56%; p = 0.99), but the rate of additional drainage was higher in uni-ENBD group. Although TRBO and overall survival time after SEMS deployment were not different between the groups (p = 0.11 and 0.78, respectively), the incidence of early adverse events tended to be higher in the bi-SEMS group (5.3% vs. 28%; p = 0.11). (4) Conclusions: Our study failed to demonstrate the superiority of bilateral over unilateral biliary drainage in terms of functional success rate and TRBO.