Comparison 7. [Radial] In‐plane B‐mode ultrasound versus out‐of‐plane B‐mode ultrasound.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
7.1 First‐attempt success rate	8	1051	Risk Ratio (M‐H, Random, 95% CI)	0.85 [0.65, 1.12]
7.2 First‐attempt success rate ‐ trials at low risk of bias	5	616	Risk Ratio (M‐H, Random, 95% CI)	0.92 [0.73, 1.17]
7.3 Overall success rate	8	1051	Risk Ratio (M‐H, Random, 95% CI)	1.00 [0.96, 1.05]
7.4 Overall success rate ‐ trials at low risk of bias	5	616	Risk Ratio (M‐H, Random, 95% CI)	1.05 [0.95, 1.16]
7.5 Time needed for a successful procedure	9	1134	Mean Difference (IV, Random, 95% CI)	‐0.06 [‐0.16, 0.05]
7.6 Time needed for a successful procedure ‐ trials at low risk of bias	6	699	Mean Difference (IV, Random, 95% CI)	‐0.05 [‐0.23, 0.12]
7.7 Major haematoma	9	1159	Risk Ratio (M‐H, Random, 95% CI)	0.49 [0.22, 1.08]
7.8 Major haematoma ‐ trials at low risk of bias	6	724	Risk Ratio (M‐H, Random, 95% CI)	0.59 [0.23, 1.54]
7.9 Adverse events (thrombosis)	5	688	Risk Ratio (M‐H, Random, 95% CI)	3.18 [0.13, 76.69]
7.10 Adverse events (thrombosis) ‐ trials at low risk of bias	4	538	Risk Ratio (M‐H, Random, 95% CI)	3.18 [0.13, 76.69]
7.11 Adverse events (oedema)	3	421	Risk Ratio (M‐H, Random, 95% CI)	0.07 [0.00, 1.14]
7.12 Adverse events (oedema) ‐ trials at low risk of bias	2	271	Risk Ratio (M‐H, Random, 95% CI)	0.07 [0.00, 1.14]
7.13 Adverse events (vasospasm)	6	748	Risk Ratio (M‐H, Random, 95% CI)	0.80 [0.24, 2.69]
7.14 Adverse events (vasospasm) ‐ trials at low risk of bias	5	598	Risk Ratio (M‐H, Random, 95% CI)	0.95 [0.25, 3.54]
7.15 Adverse events (posterior wall damage)	3	375	Risk Ratio (M‐H, Random, 95% CI)	0.45 [0.10, 1.97]
7.16 Adverse events (ischaemia)	2	327	Risk Ratio (M‐H, Fixed, 95% CI)	0.27 [0.05, 1.42]