A search for arteriovenous anastomoses in human skin using ultrasound Doppler

The possible existence of arteriovenous anastomoses (AVAs) in skin regions of the head and thorax has been investigated using the synchronous vasomotion of the AVAs. Simultaneous pairs of blood velocity recordings were made using pulsed, bidirectional Doppler ultrasound. In each pair of registrations, blood velocity was recorded in a reference artery supplying a skin area known to contain AVAs (the radial artery) together with one of four other arteries investigated, i.e. the facial artery, the angular artery, the temporal artery, and the cutaneous branches of the lateral thoracic artery. The typical large, regular fluctuations in blood velocities caused by synchronous vasomotion in the AVAs in the skin of the hand and fingers were observed invariably in the radial artery. Similar flow variations were found in the angular artery. The fluctuations in this and the radial artery were, in turn, found to be synchronous. However, we have not been able to find the flow pattern characteristic of AVA vasomotion in the temporal artery or in the cutaneous branches of the lateral thoracic artery. These results show that the skin area of the nose supplied by the angular artery contains AVAs. These AVAs partly may explain the important role of face skin in temperature regulation. These results also support the earlier assumptions that there are no or very few AVAs in the skin areas supplied by the temporal artery and the cutaneous branches of the lateral thoracic artery.