Reliability of Allen's test in selection of patients for radial artery harvest

Background. Alien's test is widely used to assess the ulnar collateral bloo d supply of the hand before radial artery harvest for coronary bypass surge ry. This study was performed to determine the optimum cut-off point for a p ositive Alien's test and the clinical reliability of Alien's test in this r ole. Methods. Patients undergoing coronary artery bypass surgery were examined b y independent observers using both Alien's test and a Doppler ultrasound te st of the ulnar collateral circulation. Results. We examined 93 hands in 47 patients; mean age was 63.6 years. Rece iver operating characteristic analysis found that at a conventional cut-off of 6 seconds on Alien's test had a sensitivity of 54.5%, specificity of 91 .7%, and diagnostic accuracy of 78.5%. At a cut-off of 5 seconds diagnostic accuracy was maximal (79.6%), with sensitivity of 75.8% and specificity of 81.7%; 100% sensitivity occurred at a cut-off of 3 seconds, with specifici ty of 27% and diagnostic accuracy of 52%. Conclusions. At no cut-off point does Alien's test perform satisfactorily a s a discriminatory test. It should be replaced by more objective tests, suc h as Doppler ultrasound. (C) 2000 by The Society of Thoracic Surgeons.