Modified long-axis in-plane ultrasound-guided radial artery cannulation in adult patients: A randomized controlled trial

•A modified ultrasound approach increased the success rate of arterial cannulation.•The modified approach showed shorter cannulation time and a lower rate of haematoma.•The artery axis is kept in the ultrasound plane to obtain the maximum artery diameter.•Two signal lines on the probe increase the geometrical accuracy of puncturing.