<P> The utility of the modified Allen's test is questionable, and no direct correlation with reduced ischemic complications of radial artery cannulation have ever been proven . In 1983, Slogoff and colleagues reviewed 1,782 radial artery cannulations and found that 25% of them resulted in complete radial artery occlusion, without apparent adverse effects . A number of reports have been published in which permanent ischemic sequelae occurred even in the presence of a normal Allen's test . In addition, the results of Allen's tests do not appear to correlate with distal blood flow as demonstrated by fluorescein dye injections . </P> <P> Further modifications to the test have been proposed to improve reliability . </P>

Explain the modified allen test and tinel's sign