Comparison of metal stents versus plastic stents for preoperative biliary drainage: a meta-analysis of five randomized controlled trials

12-mm Versus 10-mm Metallic Stents for Malignant Biliary Obstructions: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Endoscopic drainage of malignant biliary obstruction using metal stents is widely used to treat obstructive jaundice. However, the occurrence of stent occlusion or migration raises the hypothesis using stents with larger diameters may be associated with better outcomes.

METHODS

PubMed, Embase, and Cochrane databases were systematically searched for studies comparing 10-mm vs. 12-mm covered metallic stents for recurrent unresectable biliary obstruction. The primary outcomes were recurrent biliary obstruction (RBO) and time to RBO (TRBO). Statistical analyses were performed using R software version 4.3.1. The risk ratio (RR) was used for binary outcomes, with their respective 95% confidence interval (CI). Heterogeneity was assessed using the Cochran Q test and I2 statistics.

RESULTS

We included five studies-one randomized clinical trial and four cohort studies-totaling 520 patients. Among these, 280 received 10-mm stents, while 240 were treated with 12-mm stents. The 12-mm stent is associated with a greater TRBO (HR 1.72; 95% CI 1.36 to 2.18), lower incidence of RBO (RR 0.59; 95% CI 0.44 to 0.78; I2=34%), and stent obstruction (RR 0.52; 95% CI 0.34 to 0.81; I2=33%). No significant differences were found for stent migration and adverse events rate between groups.

CONCLUSION

The 12-mm metallic stents significantly increase stent patency and reduce the incidence of RBO and stent obstruction in managing recurrent unresectable biliary obstruction, with no differences regarding stent migration and adverse events compared to 10-mm stents.

Fully covered self-expandable metallic stents versus plastic stents for preoperative biliary drainage in patients with pancreatic head cancer and the risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis

Objectives

Optimal stents for preoperative biliary drainage (PBD) for patients with possible resectable pancreatic cancer remain controversial, and risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP), followed by PBD, are unknown. In this study, the efficacy and safety of fully covered self-expandable metallic stents (FCSEMSs) and plastic stents (PSs) were compared, and the risk factors for PEP, followed by PBD, were investigated for patients with pancreatic cancer.

Methods

Consecutive patients with pancreatic cancer who underwent PBD between April 2005 and March 2022 were included. We retrospectively evaluated recurrent biliary obstruction, adverse events (AEs), and postoperative complications for FCSEMS and PS groups and investigated the risk factors for PEP.

Results

A total of 105 patients were included. There were 20 patients in the FCSEMS group and 85 patients in the PS group. For the FCSEMS group, the rate of recurrent biliary obstruction (0% vs. 25%, p = 0.03) was significantly lower. There was no difference in AE between the two groups. No significant differences were observed in the overall postoperative complications, but the volume of intraoperative bleeding was larger for the PS group than it was for the FCSEMS group (p < 0.001). From multivariate analysis, being female and lack of main pancreatic duct dilation were independent risk factors for pancreatitis (odds ratio, 5.68; p = 0.028; odds ratio, 4.91; p = 0.048).

Conclusions

FCSEMSs are thought to be preferable to PSs for PBD due to their longer time to recurrent biliary obstruction. Being female and the lack of main pancreatic duct dilation were risk factors for PEP.

Fully covered versus partially covered self-expandable metal stents for palliation of distal malignant biliary obstruction: a systematic review and meta-analysis

BACKGROUND AND AIMS

Self-expandable metal stents (SEMSs) are standardly used for distal malignant biliary obstruction (dMBO). Although data suggest that covered versus uncovered SEMSs increase the time to recurrent biliary obstruction (TRBO), no data are available for fully covered (FC) versus partially covered (PC) designs.

METHODS

PubMed, Scopus, and Cochrane databases were screened up to January 2023 for studies concerning dMBO treated by an FC- or PC-SEMS and describing adverse events (AEs), recurrences, or TRBO for specific design subpopulations. Pooled proportions or means were calculated using a random-effects model. Several subanalyses were preplanned, including a subanalysis restricted to prospective studies and unresectable diseases. Heterogeneity and publication bias were explored. Standardized differences (d-values) were calculated between groups.

RESULTS

From 1290 records, 62 studies (3327 using FC-SEMSs and 2322 using PC-SEMSs) were included. FC- versus PC-SEMSs showed negligible differences in the rate of total AEs (12% vs 9.9%) and all specific AEs, including cholecystitis (2.5% vs 2.6%). In a subanalysis restricted to prospective studies and unresectable diseases, the rate of RBO was comparable between FC-SEMSs (27.3% [95% confidence interval {CI}, 23.7-31.2], I2 = 35.34%) and PC-SEMSs (25.3% [95% CI, 20.2-30.7], I2 = 85.09%), despite small differences (d-values between .186 and .216) in the rate of ingrowth (.5% vs 2.9%) favoring FC-SEMSs and migration (9.8% vs 4.3%) favoring PC-SEMSs. TRBO was shorter for FC-SEMSs (238 days [95% CI, 191-286], I2 = 63.1%) versus PC-SEMSs (369 days [95% CI, 290-449], I2 = 71.9%; d-value = .116).

CONCLUSIONS

Despite considerable heterogeneity and small standardized differences, PC-SEMSs consistently exhibited longer TRBO than FC-SEMSs across analyses, without any other differences in AE rates, potentially proposing PC-SEMSs as the standard comparator and TRBO as the primary outcome for future randomized studies on dMBO. (Clinical trial registration number: CRD42023393965.).

Metal vs plastic stents for preoperative biliary drainage in patients with periampullary cancer: An updated systematic review and meta-analysis

BACKGROUND/PURPOSE

Metal stents (MS) are recommended for preoperative biliary drainage (PBD) in patients with periampullary cancer, but whether MS are superior in terms of re-intervention and direct cost is debatable. This study aimed to compare the effects of MS and PS on the outcomes of patients with periampullary cancer.

METHODS

For this random-effects meta-analysis, electronic databases were screened for randomized controlled trials (RCTs) published until January 2022. Subgroup analyses were performed basis on the center type and presence of NAC.

RESULTS

In this meta-analysis, seven RCTs (440 participants) were included. MS reduced re-interventions (risk ratio [RR] = 0.42, 95% confidence interval [CI] = 0.25-0.72) and direct costs (mean difference = -474 USD, 95% CI = -656 to -292). PBD-related complications (RR = 0.74, 95% CI = 0.32-1.71) and postoperative complications (RR = 0.73, 95% CI = 0.45-1.17) did not differ between MS and PS. Compared PS, MS reduced postoperative complications in high-volume centers (RR = 0.64, 95% CI = 0.49-0.84) and PBD-related complications in patients receiving NAC (RR = 0.29, 95% CI = 0.08-1.08).

CONCLUSIONS

Metal stents likely reduces re-interventions and direct costs. Further studies are needed to confirm the effects of MS on the outcomes.