Plastic Versus Metal Stents for Hilar Cholangiocarcinoma: a Meta-Analysis and Systematic Review

Background: Metallic or plastic stents are used for palliating inoperable malignant hilar obstruction. It is unclear if there is a difference between metallic versus plastic stenting in these patients. Aim: To compare metallic and plastic stents for malignant hilar obstruction. Method: Study Selection Criteria: Studies using metallic or plastic stents for stenting of malignant hilar obstruction were selected. Data collection & extraction: Articles were searched in Medline, Pubmed, Ovid journals, CINAH, International pharmaceutical abstracts, old Medline, Medline non indexed citations, and Cochrane Central Register of Controlled Trials & Database of Systematic Reviews. Two reviewers independently searched and extracted data. Any differences were resolved by mutual agreement. Statistical Method: Pooled proportions were calculated using both Mantel- Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). Results: 1630 reference was identified, of which 159 relevant articles were selected and reviewed. 8 studies (N=575) for unilateral metallic stents, 7 studies (N=850) for unilateral plastic stents, 13 studies (N=340) for bilateral metallic stents and 8 studies (N=367) for bilateral plastic stents which met the inclusion criteria were included in this analysis. Pooled data are shown in Table 1 and 2. The pooled estimates calculated by fixed and random effect models were similar. The p for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10. Conclusion: For unilateral stenting, metallic stents have lower complication rate and cholangitis when compared to plastic stents. Metallic stents have a higher mean survival, patency rate, and 30 day mortality. For unilateral stenting in malignant hilar obstruction, metallic stents are superior to plastic stents. For bilateral stenting, metallic stents have lower complication rate and early cholangitis when compared to plastic stents. Metallic stents have a higher mean survival, patency rate, and 30 day mortality. For bilateral stenting in hilar malignant obstruction, metal stents are superior to plastic stents.