Biplanar Handheld Ultrasound for Transradial Artery Puncture

Ultrasound guidance is used to improve visualization of the radial artery during vascular access. Conventional high-frequency linear-array ultrasound systems provide either a short-axis or a long-axis image, depending on probe orientation and puncture technique. During puncture, the operator may need to adjust the probe repeatedly to maintain visualization of the needle tip and its position relative to the radial artery.

The TUOREN biplanar handheld ultrasound system uses a T-shaped dual-probe configuration to display simultaneous long-axis and short-axis views of the radial artery and puncture needle. The long-axis view is intended to show the needle trajectory and advancement, while the short-axis view is intended to show the lateral position of the needle relative to the vessel.

This is a prospective, randomized, parallel-group, single-center superiority trial conducted at Shanghai Fourth People's Hospital. Eligible participants scheduled for cerebral angiography or neurointerventional treatment through a transradial approach will be allocated in a 1:1 ratio using block randomization with allocation concealment.

Participants in the experimental group will undergo radial artery puncture guided by the TUOREN biplanar handheld ultrasound system. Participants in the active comparator group will undergo radial artery puncture guided by a conventional high-frequency linear-array ultrasound system using either a short-axis out-of-plane technique or a long-axis in-plane technique. Other components of the radial artery cannulation procedure will be standardized between the two groups.

The study is designed to evaluate whether simultaneous biplanar ultrasound visualization improves first-attempt radial artery cannulation success and procedural efficiency compared with conventional ultrasound guidance. Puncture attempts, procedure-related time intervals, and ultrasound findings will be recorded according to prespecified study definitions.

Inclusion criteria

• Adults aged 18 years or older, regardless of sex, who are scheduled to undergo cerebral angiography or neurointerventional treatment through a transradial approach.
• Adequate collateral circulation between the radial and ulnar arteries, as demonstrated by the modified Allen test or vascular ultrasound.
• Radial artery diameter of at least 1.5 mm on preprocedural ultrasound examination.
• Ability to understand the study procedures, willingness to participate voluntarily, and provision of written informed consent.

Exclusion criteria

• Infection or skin damage at the intended puncture site; known radial artery occlusion or severe stenosis; or inadequate collateral circulation between the radial and ulnar arteries.
• Radial artery diameter of less than 1.5 mm on preprocedural ultrasound examination, or severe radial artery tortuosity or anatomical variation that may interfere with the puncture procedure.
• Previous puncture, surgery, or trauma involving the radial artery on the intended puncture side that may have altered the local anatomy.
• Hemodynamic instability requiring urgent hemodynamic support, including cardiogenic shock or severe hypotension.
• Impaired consciousness, psychiatric illness, or any other condition that prevents the participant from cooperating with the study procedures or completing the required follow-up.
• Severe coagulation abnormality, defined as an international normalized ratio greater than 1.8 or a platelet count below 80 × 10^9/L.