Bilateral and unilateral stenting for malignant hilar obstruction: a systematic review and meta-analysis.

BACKGROUND: Stents are used for palliating inoperable malignant bile duct hilar obstruction. It is not clear if bilateral stenting provides any advantage over unilateral stenting in these patients. Compare bilateral and unilateral stenting in malignant hilar obstruction.

STUDY SELECTION CRITERIA: Studies using stents for palliation in patients with malignant hilar obstruction were selected.

DATA COLLECTION AND EXTRACTION: Articles were searched in MEDLINE, PubMed, Ovid journals, CINAH, International Pharmaceutical Abstracts, OLDMEDLINE, MEDLINE nonindexed citations, and Cochrane Central Register of Controlled Trials and Database of Systematic Reviews. Two reviewers independently searched and extracted data. Any differences were resolved by mutual agreement.

STATISTICAL METHODS: Pooled proportions were calculated using both the Mantel-Haenszel method (fixed effects model) and DerSimonian-Laird method (random effects model). The heterogeneity among studies was tested using Cochran's Q test based upon inverse variance weights. The initial search identified 1,640 reference articles, of which 169 were selected and reviewed. Thirteen studies (n = 340) for bilateral metallic stents, eight studies (n = 575) for unilateral metallic stents, eight studies (n = 367) for bilateral plastic stenting, and seven studies (n = 850) for unilateral plastic stenting which met the inclusion criteria were included in this analysis. Pooled data are shown in Tables 1 and 2. The pooled estimates by the fixed and random effect models were similar. The p for chi-squared heterogeneity for all the pooled accuracy estimates was >0.10. Bilateral metal stenting seems to have lower odds of overall complications when compared to unilateral metallic stenting. Bilateral metal stents seem to have higher odds of lowering bilirubin than unilateral metal stents, but the 30-day mortality was no different. For metal stents, bilateral metal stents are superior in palliating symptoms due to hyperbilirubinemia. Unilateral plastic stenting seems to have similar odds of overall complications, cholangitis, and 30-day mortality when compared to bilateral plastic stenting for malignant hilar strictures. In patients with malignant hilar stricture, unilateral plastic stenting is comparable to bilateral plastic stenting for adverse events.