Duplication and transposition of inferior vena cava: A meta-analysis of prevalence

Objective: The primary aim of this article was to establish the actual prevalence of transposition and duplication of the inferior vena cava and to increase awareness about them. Methods: A meta-analysis of prevalence was conducted of cases obtained from PubMed, Web of Science, and Scopus databases. Results: A total of 48 studies contained data that allowed us to estimate the prevalence of these variants (39 for duplication and 32 for transposition). The overall prevalence of duplication was 0.7%, with a 95% confidence interval between 0.5% and 0.9%; for transposition, the prevalence was 0.3%, with a 95% confidence interval between 0.2% and 0.5%. The publication bias was minimal. Duplication prevalence was significantly higher in anatomy studies compared with imaging and surgery studies; for transposition, there were no statistically significant differences by detection technique. Conclusions: The overall prevalence of duplication of the inferior vena cava is 0.7%; for transposition, it is 0.3%. Even if they are obviously rare conditions, their presence must be suspected by practitioners as they can have important clinical consequences, may require changes in the surgery protocol, or can be associated with other congenital abnormalities.