Correlation of Modified Allen Test with Doppler Ultrasonography

The feasibility of using modified Allen tests to evaluate arterial circulation in the forearm for possible radial artery grafting, and the correlation of these tests with Doppler ultrasonography, were examined. The hand circulation of 50 patients scheduled for coronary artery bypass grafting was assessed by plethysmography, pulse oximetry, and pencil Doppler, as well as Doppler ultrasonography. Flow, velocity, and diameter of the radial, ulnar, and snuffbox arteries were recorded, and radiological screening indices were evaluated to establish a standard set of criteria. The results of modified Allen tests by plethysmography and pulse oximetry demonstrated the dominance of the ulnar artery. The indices of flow × diameter and velocity × diameter, obtained from Doppler ultrasound measurements, confirmed the dominance of the ulnar artery. When compression was applied to the arteries sequentially, significant alterations were found. The arterial circulation in the forearm can be safely evaluated by the modified Allen tests with plethysmography, pulse oximetry, and pencil Doppler, as these results correlated with Doppler ultrasound.