Are self-expandable metal stents superior to plastic stents in palliating malignant distal biliary strictures? A meta-analysis and systematic review.

BACKGROUND: Palliation for inoperable malignant distal biliary strictures can be achieved with self-expandable metal stents (SEMS) and plastic stents (PS). This is a meta-analysis to compare PS and SEMS. The aim of the study is to compare clinical outcomes in patients with SEMS and PS. METHODS: Study selection criteria were studied using SEMS and PS for palliation in patients with malignant distal biliary stricture. For data collection and extraction, articles were searched in Ovid journals, Medline, Cochrane database, and Pubmed. Pooled proportions were calculated using both Mantel-Haenszel method and DerSimonian Laird method for statistical analysis. RESULTS: Initial search identified 1376 reference articles, of which 112 were selected and11 studies (N = 947) were included in this analysis. Pooled analysis showed SEMS patency to be 167.7days (95% CI = 159.2-176.3) compared to 73.3days (95% CI = 69.8-76.9) in PS. SEMS have lower odds of occlusion when compared to PS with an odds ratio of 0.48 (95% CI = 0.34-0.67). SEMS has a lower odds of cholangitis compared to SP, with an odds ratio of 0.46 (95% CI = 0.30-0.69). CONCLUSION: SEMS seem to be superior to PS with better patency periods and survival duration. SEMS have lower occlusion rates, re-intervention rates, and cholangitis.

Covered versus uncovered self-expandable metal stents for malignant biliary strictures: A meta-analysis and systematic review.

Self-expandable metal stents (SEMS) are used for palliating inoperable malignant biliary strictures. It is unclear if covered metal stents are superior to uncovered metal stents in these patients. We compared clinical outcomes in patients with covered and uncovered stents. Studies using covered and uncovered metallic stents for palliation in patients with malignant biliary stricture were reviewed. Articles were searched in MEDLINE, PubMed, and Ovid journals. Fixed and random effects models were used to calculate the pooled proportions. Initial search identified 1436 reference articles, of which 132 were selected and reviewed. Thirteen studies (n = 2239) for covered and uncovered metallic stents which met the inclusion criteria were included in this analysis. Odds ratio for stent occlusion rates in covered vs. uncovered stents was 0.79 (95 % CI = 0.65 to 0.96). Survival benefit in patients with covered vs. uncovered stents showed the odds ratio to be 1.29 (95 % CI = 0.95 to 1.74). Pooled odds ratio for migration of covered vs. uncovered stents was 9.9 (95 % CI = 4.5 to 22.3). Covered stents seemed to have significantly lesser occlusion rates, increased odds of migration, and increased odds of pancreatitis compared to uncovered stents. There was no statistically significant difference in the survival benefit, overall adverse event rate, and patency period of covered vs. uncovered metal stents in patients with malignant biliary strictures.

Diagnostic accuracy of endoscopic ultrasound in pancreatic neuroendocrine tumors: a systematic review and meta analysis.

AIM: To detect pancreatic neuroendocrine tumors (PNETs) has been varied. This study is undertaken to evaluate the accuracy of endoscopic ultrasound (EUS) in detecting PNETs. METHODS: Only EUS studies confirmed by surgery or appropriate follow-up were selected. Articles were searched in Medline, Ovid journals, Medline nonindexed citations, and Cochrane Central Register of Controlled Trials and Database of Systematic Reviews. Pooling was conducted by both fixed and random effects model). RESULTS: Initial search identified 2610 reference articles, of these 140 relevant articles were selected and reviewed. Data was extracted from 13 studies (n = 456) which met the inclusion criteria. Pooled sensitivity of EUS in detecting a PNETs was 87.2% (95%CI: 82.2-91.2). EUS had a pooled specificity of 98.0% (95%CI: 94.3-99.6). The positive likelihood ratio of EUS was 11.1 (95%CI: 5.34-22.8) and negative likelihood ratio was 0.17 (95%CI: 0.13-0.24). The diagnostic odds ratio, the odds of having anatomic PNETs in positive as compared to negative EUS studies was 94.7 (95%CI: 37.9-236.1). Begg-Mazumdar bias indicator for publication bias gave a Kendall's tau value of 0.31 (P = 0.16), indication no publication bias. The P for χ² heterogeneity for all the pooled accuracy estimates was > 0.10. CONCLUSION: EUS has excellent sensitivity and specificity to detect PNETs. EUS should be strongly considered for evaluation of PNETs.

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.