Comparison between the long-axis in-plane and short-axis out-of-plane approaches for ultrasound-guided arterial cannulation: a meta-analysis and systematic review

BACKGROUND: The two most common methods for ultrasound-guided arterial cannulation are the long-axis in-plane (LA-IP) and short-axis out-of-plane (SA-OOP) approaches. However, it is uncertain which method is more advantageous. We conducted a meta-analysis of reported randomized clinical trials (RCTs) comparing the two techniques in terms of success rate, cannulation time, and complications. METHODS: We systematically searched PubMed, Embase, and the Cochrane Library database for RCTs comparing the LA-IP and SA-OOP techniques for ultrasound-guided arterial cannulation published from inception through April 31, 2022. The Cochrane Collaboration’s Risk of Bias Tool was used to evaluate the methodological quality of each RCT. Review Manager 5.4 and Stata/SE 17.0 were used to analyze the two primary outcome measures (first-attempt success rate and total success rate) and two secondary outcome measures (cannulation time and complications). RESULTS: A total of 13 RCTs with 1,377 patients were included. There were no significant differences in first-attempt success rate (risk ratio [RR], 0.93; 95% confidence interval [CI], 0.78–1.12; P = 0.45; I(2) = 84%) and overall success rate (RR, 0.99; 95% CI, 0.95–1.02; P = 0.48; I(2) = 57%). When compared with the LA-IP technique, the SA-OOP technique was associated with an increased incidence of posterior wall puncture (RR, 3.01; 95% CI, 1.27–7.14; P = 0.01; I(2) = 79%) and hematoma (RR, 2.15; 95% CI, 1.05–4.37; P = 0.04; I(2) = 63%). There was no significant difference in the incidence of vasospasm between techniques (RR, 1.26; 95% CI, 0.37–4.23; P = 0.07; I(2) = 53%). CONCLUSIONS: The present results suggest that the SA-OOP technique is associated with a higher incidence of posterior wall puncture and hematoma than the LA-IP technique, whereas success rates are similar for the two ultrasound-guided arterial cannulation techniques. These findings should be experimentally evaluated in a more rigorous manner due to high inter-RCT heterogeneity.