Assessment and Access of Radial Artery

Current Guidelines and Evidence

The American Heart Association recommends that performing Allen's or Barbeau test to confirm dual arterial circulation to the hand is "only of historical interest" 1
Recent studies have found no differences in thumb capillary lactate, grip strength, or incidence of ischemia between patients with normal and abnormal Allen's test results who underwent transradial access 1
The American College of Cardiology, as per the referenced guidelines, implies that cardiac specialists no longer confirm collateral circulation to the hand with Allen's test as it does not predict hand ischemia 2
The RADAR trial found no evidence of hand ischemia in patients undergoing transradial access, even in those with abnormal Allen's test results 3

The robust collateral circulation in the hand from the ulnar artery makes ischemic complications from radial artery access extraordinarily rare 2
Radial artery occlusion occurs in less than 5% of patients with current prevention strategies and is almost always clinically silent due to collateral circulation 3
Ultrasound guidance increases the speed and efficacy of transradial access, decreasing time to access and number of attempts 3

Ultrasound imaging may be helpful in identifying an occluded radial artery that fills via retrograde collaterals 1
The reverse Allen or Barbeau test may also help identify occluded radial arteries 1

Routine application of the Allen or Barbeau test is not a useful triage strategy for radial artery access 1
An abnormal Allen's test should not preclude transradial access 1, 2
Patients should not be denied a radial approach simply because of a "failed" Allen test 2
Assessment of the radial pulse remains important, but the Allen's test is no longer considered necessary 1