RESUMEN
By intrabrachial artery injections of a bolus of human albumin microspheres labeled with 99mTc in patients with primary or secondary Raynaud's phenomenon (RP) and in a group of healthy volunteers, the authors developed a method of detecting the patency rate of arteriovenous anastomoses (AVA) in the hand, after local heat and cold stimulation, by quantifying the radioactivity of the lungs expressed as a percentage of an intravenously injected radionuclide dose. With strain gauge plethysmography, simultaneous changes in the digital total (DTF) flow were also measured. After exposure of fingers to cold, 25 of 26 subjects had a clear reduction in both DTF and the AVA patency rate (APR) in comparison with the corresponding heat values. The RP patients, in particular, showed a statistically significant reduction in DTF (P less than 0.001) and in APR (P less than 0.001). These results appear to be consistent with the onset of critically reduced patency of the AVA of the hand during the ischemic phase of RP.