New 10F soft and pliable polyurethane stents decrease the migration rate compared with conventional 10F polyethylene stents in hilar biliary obstruction: results of a pilot study

Effect of percutaneous stenting strategy of unresectable malignant hilar biliary obstruction by three-dimensional reconstruction volumetry

PURPOSE

To explore clinical outcomes of percutaneous stent implantation using volumetric criteria for unresectable malignant hilar biliary obstruction (MHBO). Additionally, aimed to identify the predictors of patients' survival.

METHODS

Seventy-two patients who were initially diagnosed with MHBO between January 2013 to December 2019 in our center were retrospectively included. Patients were stratified according to the drainage achieved ≥50%, <50% of the total liver volume. Patients were divided into two groups: Group A (≥50% drainage), and Group B (<50% drainage). The main outcomes were evaluated in terms of relief of jaundice, effective drainage rate, and survival. Related factors that affect survival were analyzed.

RESULTS

62.5% of the included patients reached effective biliary drainage. The successful drainage rate was significantly higher in Group B than in Group A (p < 0.001). The median overall survival (mOS) of included patients was 6.4 months. Patients who received drainage ≥50% of hepatic volume achieved longer mOS than those who received drainage <50% of hepatic volume (7.6 months vs. 3.9 months, respectively, p = 0. 011). Patients who received effective biliary drainage had longer mOS than those who received ineffective biliary drainage (10.8 months vs. 4.4 months, respectively, p < 0.001). Patients who received anticancer treatment had longer mOS than those who only received palliative therapy (8.7 months vs. 4.6 months, respectively, p = 0.014). In the multivariate analysis, KPS Score ≥ 80 (p = 0.037), ≥50% drainage achieved (p = 0.038), and effective biliary drainage (p = 0.036) were protective prognostic factors that affected patients' survival.

CONCLUSION

Drainage achieved ≥50% of the total liver volume by percutaneous transhepatic biliary stenting seemed to have a higher effective drainage rate in MHBO patients. Effective biliary drainage may create chances for these patients to receive anticancer therapies that seem to provide survival benefits.

Endoscopic management of benign and malignant hilar stricture

Management of hilar strictures pose a significant challenge for endoscopists. Several strategies have been demonstrated in the last decade beyond decompression, however, there remains controversy and minimal consensus in the literature. This review seeks to summarize the current literature and discuss emerging therapies, such as photodynamic therapy and radiofrequency ablation.

Stent placement above the sphincter of Oddi is a useful option for patients with inoperable malignant hilar biliary obstruction

BACKGROUND AND AIMS

Endoscopic biliary drainage (EBD) is essential for the management of malignant hilar biliary obstruction (MHBO). We prospectively evaluated the efficacy and safety of "inside-stent" therapy, where a plastic stent is placed above the sphincter of Oddi without endoscopic sphincterotomy, in patients with inoperable MHBO.

METHODS

This study was a multicenter, single-blinded, randomized controlled trial at three centers. Patients with inoperable MHBO were enrolled in this study, and randomly assigned to receive an inside-stent or conventional-stent therapy. The primary endpoint was cumulative stent patency of the initial stent. The secondary endpoints were second stent patency, technical and clinical success rate, adverse events, re-intervention rate, and overall patient survival.

RESULTS

Forty-three patients were randomly assigned to the inside-stent group (n = 21) or the conventional-stent group (n = 22). The median cumulative stent patency of the initial stent was 123 days in the inside-stent group and 51 days in the conventional-stent group (P = .031). For patients with the initial stent dysfunction in the conventional-stent group, the inside-stent was placed as a second stent, and its patency was significantly longer than that of the initial stent (P = .0001). The technical and clinical success rate, re-intervention rate, second stent patency, adverse events, and survival probability did not differ between the groups.

CONCLUSIONS

Inside-stent therapy appears to be useful not only as an initial stent but also as a second stent for patients with inoperable MHBO.

TRIAL REGISTRATION NUMBER

UMIN000004587.

Fishing line assisted endoscopic placement of multiple plastic biliary stents for unresectable malignant hilar biliary obstruction: a retrospective study

BACKGROUND AND AIMS

Stent migration is one of the most common complications during the placement of multiple plastic biliary stents (MPBS) under endoscopy. This study aims to evaluate the feasibility and efficiency of the fishing line assisted (FLA) method for preventing the complication.

METHODS

Patients with unresectable malignant hilar biliary obstruction (MHBO) who undergone endoscopic placement of MPBS using the FLA or conventional method from May 2018 to April 2021 in our center were enrolled in the study. The endpoints of this study were the stent migration rate, technical success rates, adverse events rates, times of stent migration, and the procedure time.

RESULTS

FLA group (N = 19) and conventional group (N = 22) had similar baseline characteristics of the patients. The technical success rates (100% vs. 95.5%; P > 0.05), ERCP-related adverse events rates (5.3% vs. 4.5%; P > 0.05), and the stent-related adverse events rates (0% vs. 4.5%; P > 0.05) were no significant differences between the FLA and conventional groups. MPBS inserted using the conventional method consumed more time (median, 33.9 min vs. 15.6 min; P < 0.05) method and increased the times of stent migration (median, 3 times vs. 0 times; P < 0.05) than using the FLA method. Even if no statistical difference was detected in the stent migration rate between groups, this rate was lower in the FLA group than the conventional group (0% vs. 13.6%; P > 0.05).

CONCLUSIONS

FLA method is an effective technique for MPBS implantation to prevent stent migration during endoscopic retrograde cholangiography (ERCP). The method should be applied to patients with unresectable MHBO who need to place MPBS.

[Mechanisms and prevention of biliary stent occlusion]

One of significant achievements of modern endoscopy is development of retrograde biliary stenting for obstructive jaundice. This method ensured widespread application of endoscopic decompression in the treatment of patients with malignant biliary obstruction as preparation before radical surgery and final palliative care. Endoscopic retrograde transpapillary stenting firmly took its place together with antegrade and percutaneous stenting. There are certain advantages of this technique including minimally invasiveness and favorable quality of life. However, this approach is associated with some drawbacks associated with stent occlusion and difficult correction of this complication. The maximum diameter of the plastic stent (PS) is determined by the width of the working channel of the duodenoscope. In this regard, self-expandable metal stents (SEMS) were developed to increase the diameter of bile drainage channel. SEMS are associated with prolonged function. However, there is another problem. It is a germination of SEMS followed by impossible removal of the stent for its subsequent replacement. A further step in development of endoscopic biliary stents was the use of special SEMS coating to exclude tumor or granulation ingrowth. The problem of biliary stent occlusion remains relevant despite some improvement of stenting results. Mechanisms of occlusion of biliary stents and prevention of these events are discussed in this review.

Endoscopic management of duodenal perforations caused by migrated biliary plastic stents

Background and study aims  Duodenal perforation by migration of plastic stents placed to treat biliary lesions is rare but can be life-threatening. Surgical management is preferred, but it may increase risks of mortality and morbidity, especially in patients with underlying comorbidities and those of advanced age. We describe five cases of duodenal perforation that were successfully managed endoscopically. Four patients were elderly, and one had end-stage renal disease. We used cylindrically adapted cap-fitted endoscopy to successfully retrieve migrated plastic stents and to close the perforated walls with hemoclips. No post-procedural complication was noted. In conclusion, endoscopic management is appropriate as a first-line approach in patients with duodenal perforations caused by plastic stent migration.

Endoscopic Drainage of >50% of Liver in Malignant Hilar Biliary Obstruction Using Metallic or Fenestrated Plastic Stents

OBJECTIVES

Endoscopic drainage of complex hilar tumors has generally resulted in poor outcomes. Drainage of >50% of liver volume has been proposed as optimal, but not evaluated using long multifenestrated plastic stents (MFPS) or self-expanding metal stents (SEMS). We evaluated outcomes of endoscopic drainage of malignant hilar strictures using optimal strategy and stents, and determined factors associated with stent patency, survival, and complications.

METHODS

Cross-sectional study was conducted at an academic center over 5 years. MFPS (10 French or 8.5 French) or open-cell SEMS were used for palliation of unresectable malignant hilar strictures, with imaging-targeted drainage of as many sectors as needed to drain >50% of viable liver volume. Risk factors were evaluated using regression analysis. The cumulative risk was assessed using Kaplan-Meier analysis.

RESULTS

77 patients with malignant hilar biliary strictures (median Bismuth IV) underwent targeted stenting (41 MFPS and 36 SEMS). Comparing MFPS vs. SEMS, technical success (95.1 vs. 97.2%, P=0.64), clinical success (75.6 vs. 83.3%, P=0.40), frequency of multiple stents (23/41 vs. 25/36, P=0.19), survival and adverse events were similar, but stent patency was significantly shorter (P<0.0001). Factors associated with survival were Karnofsky score and serum bilirubin level at presentation. Outcomes were independent of Bismuth class with acceptable results in Bismuth III and IV.

CONCLUSIONS

Endoscopic biliary drainage with MFPS or open-cell SEMS targeting >50% of viable liver resulted in effective palliation in patients with complex malignant hilar biliary strictures. Patency was shorter in the MFPS group, but similar survival and complications were found when comparing MFPS and SEMS group.

Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention

Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, we will discuss basic mechanisms of plastic stent occlusion, along with a systematic summary of previous efforts and related studies to improve stent patency and potential new techniques to overcome existing limitations.

An Update to Hepatobiliary Stents

Endoscopic stent placement is a common primary management therapy for benign and malignant biliary strictures. However, continuous use of stents is limited by occlusion and migration. Stent technology has evolved significantly over the past two decades to reduce these problems. The purpose of this article is to review current guidelines in managing malignant and benign biliary obstructions, current endoscopic techniques for stent placement, and emerging stent technology. What began as a simple plastic stent technology has evolved significantly to include uncovered, partially covered, and fully covered self-expanding metal stents (SEMS) as well as magnetic, bioabsorbable, drug-eluting, and antireflux stents.(1).

Endoscopic management of benign biliary strictures

The majority of recent studies of benign biliary strictures (BBSs) have reported on treatment of stenotic injuries following cholecystectomy, orthotopic liver transplantation, living donor liver transplantation, chronic pancreatitis, and different inflammatory conditions such as common bile-duct-related strictures. Information about previous surgical procedures is very important for making a BBS diagnosis. Diagnostic tools for indeterminate strictures have increased to include (1) highly specialized cytological techniques such as fluorescence in situ hybridization, (2) cholangioscopy, and (3) endoscopic ultrasound with fine needle aspiration (FNA) and intraductal ultrasound. Magnetic resonance cholangiopancreatography before endoscopic retrograde cholangiopancreatography (ERCP) usually provides an adequate map to plan the endoscopic therapy. After traversing the stricture with a guidewire and, occasionally, performing balloon dilatation, plastic stents continue to be the basic endotherapy, trying to insert the maximum possible number, with an exchange every 3 months during a 12-month period. Progressive stenting requires a median number of five ERCPs; therefore, it is technically demanding and burdensome but has an average of 80% long-term durable stricture dilation. For not-hilar BBS, fully covered self-expanding metal stents (FCSEMSs) are emerging as a promising therapy needing fewer of the endoscopist's technical skills and reducing ERCP procedures and, probably, costs. To equal a 10-mm diameter provided by a single FCSEMS, about three plastic stents placed side-by-side are needed. Manufacturers are working to improve FCSEMS designs to reduce migration rate and to allow an easy extraction after several months in place. Many studies have tried to show reproducible protocols for the duration of FCSEMS therapy and the results in different types of BBSs.

Future developments in biliary stenting

Biliary stenting has evolved dramatically over the past 30 years. Advancements in stent design have led to prolonged patency and improved efficacy. However, biliary stenting is still affected by occlusion, migration, anatomical difficulties, and the need for repeat procedures. Multiple novel plastic biliary stent designs have recently been introduced with the primary goals of reduced migration and improved ease of placement. Self-expandable bioabsorbable stents are currently being investigated in animal models. Although not US Food and Drug Administration approved for benign disease, fully covered self-expandable metal stents are increasingly being used in a variety of benign biliary conditions. In malignant disease, developments are being made to improve ease of placement and stent patency for both hilar and distal biliary strictures. The purpose of this review is to describe recent developments and future directions of biliary stenting.