Efficacy and safety evaluation of paclitaxel-loaded metal stents in patients with malignant biliary obstructions

An exploratory research on antitumor effect of drug-eluting slow-releasing electrospinning membranes

Objective

To evaluate the long-term inhibition of malignant biliary tumor growth using paclitaxel (PTX)-covered polycaprolactone (PCL) electrospun membranes.

Methods

A mixture of PCL, a material used to fabricate polymer stents, and PTX, a widely used chemotherapeutic agent, was synthesized by electrospinning. After preparing the drug-eluting membrane, drug release and fiber degradation were assessed in vitro under different pH conditions. The QBC939 cholangiocarcinoma cell line was cultured to establish a xenograft nude mouse model. Finally, the drug-eluting membrane was implanted into the mouse model, and the relative tumor inhibition rate was evaluated.

Results

A new PTX-loaded PCL electrospun fiber membrane was developed. The drug release rate was about 20-40% in the 32-day release cycle, and the release quantity was between 20 and 170 mg. As pH decreased, the release rate increased significantly. The degradation rate of the fiber membranes in vitro was approximately 20-48%, and was positively correlated with the drug loading rate. In animal experiments, the growth of tumors in mice was suppressed using drug-eluting membranes.

Conclusion

The PTX-loaded PCL electrospun fiber membrane enhanced the long-term drug release and exhibited excellent antitumor effects in vivo.

Biliary drainage in malignant biliary obstruction: an umbrella review of randomized controlled trials

Background

There are still many controversies about biliary drainage in MBO, and we aimed to summarize and evaluate the evidence associated with biliary drainage.

Methods

We conducted an umbrella review of SRoMAs based on RCTs. Through July 28, 2022, Embase, PubMed, WOS, and Cochrane Database were searched. Two reviewers independently screened the studies, extracted the data, and appraised the methodological quality of the included studies. GRADE was used to evaluate the quality of the evidence.

Results

36 SRoMAs were identified. After excluding 24 overlapping studies, 12 SRoMAs, including 76 RCTs, and 124 clinical outcomes for biliary drainage in MBO were included. Of the 124 pieces of evidence evaluated, 13 were rated "High" quality, 38 were rated "Moderate", and the rest were rated "Low" or "Very low". For patients with MBO, 125I seeds+stent can reduce the risk of stent occlusion, RFA+stent can improve the prognosis; compared with PC, SEMS can increase the risk of tumor ingrowth and reduce the occurrence of sludge formation, and the incidence of tumor ingrowth in C-SEMS/PC-SEMS was significantly lower than that in U-SEMS. There was no difference in the success rate of drainage between EUS-BD and ERCP-BD, but the use of EUS-BD can reduce the incidence of stent dysfunction. For patients with obstructive jaundice, PBD does not affect postoperative mortality compared to direct surgery. The use of MS in patients with periampullary cancer during PBD can reduce the risk of re-intervention and stent occlusion compared to PC. In addition, we included four RCTs that showed that when performing EUS-BD on MBO, hepaticogastrostomy has higher technical success rates than choledochoduodenostomy. Patients who received Bilateral-ENBD had a lower additional drainage rate than those who received Unilateral-ENBD.

Conclusions

Our study summarizes a large amount of evidence related to biliary drainage, which helps to reduce the uncertainty in the selection of biliary drainage strategies for MBO patients under different circumstances.

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

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

Futuristic Developments and Applications in Endoluminal Stenting

Endoscopic stenting is a well-established option for the treatment of malignant obstruction, temporary management of benign strictures, and sealing transmural defects, as well as drainage of pancreatic fluid collections and biliary obstruction. In recent years, in addition to expansion in indications for endoscopic stenting, considerable strides have been made in stent technology, and several types of devices with advanced designs and materials are continuously being developed. In this review, we discuss the important developments in stent designs and novel indications for endoluminal and transluminal stenting. Our discussion specifically focuses on (i) biodegradable as well as (ii) irradiating and drug-eluting stents for esophageal, gastroduodenal, biliary, and colonic indications, (iii) endoscopic stenting in inflammatory bowel disease, and (iv) lumen-apposing metal stent.

Drug Eluting Versus Covered Metal Stents in Malignant Biliary Strictures-Is There a Clinical Benefit?: A Systematic Review and Meta-Analysis

GOALS/BACKGROUND

Patients with malignant biliary obstruction (MBO) often require transpapillary stenting for symptomatic relief and biliary decompression. Plastic stents and uncovered metal stents are now replaced by covered self-expanding metal stents (SEMS). However, stent occlusion from tumor overgrowth and chronic inflammation continues to be an issue. Drug-eluting stents (DES), through an antitumor paclitaxel membrane, have been used to combat this problem. The aim of this study was to conduct a meta-analysis comparing DES to SEMS in MBO.

STUDY

Multiple databases were searched to identify studies that compared the clinical outcomes of SEMS and DES in patients with MBO. Random-effects model was used to calculate the pooled odds ratio and the pooled individual outcomes. Our primary goals were to assess the stent patency and overall survival in days. Secondary outcomes assessed the individual reported adverse events and/or complications.

RESULTS

Five studies including 348 patients (175 males and 173 females) were included. The pooled odds ratio of stent patency was 1.03 (95% confidence interval: 0.68-1.54, P=0.9) and overall survival was 1.16 (95% confidence interval: 0.63-2.11, P=0.6). The pooled rate of stent patency was 168.3 (95% 140.7-196.4) days for DES and 149.4 (117.6-181.2) days for SEMS. The pooled rate of overall survival was 267.2 (206.2-328.2) days for DES and 218.2 (148.5-287.8) days for SEMS.

CONCLUSION

On the basis of this meta-analysis, DES and SEMS seem to demonstrate comparable clinical outcomes in patients with malignant biliary strictures. Reported adverse events and/or complications were comparable as well.

Advances in stent therapy for malignant biliary obstruction

Malignant biliary obstruction (MBO), result of pancreatobiliary diseases is a challenging condition. Most patients with MBO are inoperable at the time of diagnosis, and the disease is poorly controlled using external-beam radiotherapy and chemotherapy. Biliary stent therapy emerged as a promising strategy for alleviating MBO and prolonging life. However, physicians find it difficult to determine the optimal type of biliary stent for the palliation of MBO. Here, we review the safety and efficacy of available biliary stents, used alone or in combination with brachytherapy, photodynamic therapy and advanced chemotherapeutics, in patients with pancreatobiliary malignancies and put forward countermeasures involving stent obstruction. Furthermore, 3D-printing stents and nanoparticle-loaded stents have broad application prospects for fabricating tailor-made biliary stents.

Construction of multilayer films with bactericidal and long-term antitumor drug release properties as a non-vascular stent coating for therapy in obstruction

An antibacterial and antitumor coating for non-vascular stent was constructed via the layer-by-layer electrostatic self-assembly method.