Short-axis versus long-axis approach for ultrasound-guided vascular access: An updated systematic review and meta-analysis of randomised controlled trials

There are two approaches for ultrasound (US)-guided vessel cannulation: the short axis (SA) approach and the long axis (LA) approach. However, it remains to be seen which approach is better. Therefore, we performed the present updated systematic review and meta-analysis to assess the effectiveness and safety of US-guided vascular cannulation between the SA and LA techniques. We performed a comprehensive electronic database search in PubMed, Embase, Cochrane Library and Web of Science for the relevant studies from inception to June 2022. Randomised controlled trials comparing the SA approach and the LA approach for US-guided vascular access were incorporated in this updated meta-analysis. The first-attempt success rate was the primary outcome. The secondary outcomes were the overall success rate, cannulation time, number of attempts and the incidence of complications. The statistical analysis was conducted using RevMan software (version 5.4; the Nordic Cochrane Centre, the Cochrane Collaboration, Copenhagen, Denmark). The Cochrane risk of bias tool was used to evaluate each study's potential risk for bias. In total, 16 studies consisting of 1885 participants were incorporated in this updated meta-analysis. No statistically significant difference was found between the SA and LA vascular access techniques for first-pass success rate (risk ratio = 1.07, 95% confidence interval: 0.94-1.22). The overall cannulation success rate, complication rate, average cannulation time and average number of attempts were not significantly different between the SA and LA groups. This updated meta-analysis demonstrated that the SA and LA approaches of US-guided vessel cannulation are similar regarding first-pass success, overall cannulation success rate, total complication rate, cannulation time and the number of attempts.