Comparison of Mill Suss™-guided radial artery catheterization with the long-axis in-plane ultrasound-guided method under general anesthesia: a randomized controlled trial.

Continuous arterial blood pressure measurement is an effective perioperative monitoring method in patients with high-risk comorbidities. Recently, ultrasound guidance has been reported to facilitate radial artery catheterization. A new device, Mill Suss™, has also been developed for visualization of the radial artery and superficial veins using near-infrared laser light. In this study, we hypothesized that the Mill Suss-guided method might reduce the time and the number of attempts required for radial artery catheterization under general anesthesia, as compared to the long-axis in-plane ultrasound-guided method. Seventy-two adult patients aged 20-80 years, ASA physical status I or II, were randomly assigned to the Mill Suss-guided group (Group M: n = 36) or ultrasound-guided group (Group U: n = 36). Primary outcomes were the time required for successful radial artery catheterization and the number of cannulation attempts. There were no significant differences in the characteristics of patients between the two groups. The time required for successful radial artery catheterization was significantly shorter in Group M than in Group U. The number of attempts for successful cannulation was not statistically significantly different between the two groups. However, the results might be different among anesthesiologists well experienced in the ultrasound-guided method.