Competição de fluxo fisiológica na circulação arterial do arco palmar

Abstract

Flow competition has been described as a situation in which two vessels are responsible for blood supply to the same area and that the flow of one of them could be impaired according to the flow of the other one. The present literature discusses this situation in the context of myocardial revascularization where there is a risk of occlusion of the surgically implanted graft when the obstruction in the native coronary that receives the anastomosis is not severe but only moderate. However, there are parts of the human body, such as the hand, where there is a closed system in which two arteries function physiologically to supply arterial blood to the same site. Given the clinical relevance of the subject, evaluation of the arterial circulation flow of the palmar arch is the target of this study. This study aims to evaluate the physiological flow competition, using as a model the arterial circulation of the palmar arch. It was analyzed the flow of radial artery and ulnar artery in 23 healthy individuals using two- dimensional Doppler flowmetry ultrasonography. The variables obtained were: peak systolic velocity (PSV), end diastolic velocity (eDV) and resistance, at rest and during compression of the ulnar and radial arteries. When the ulnar artery was compressed, the radial artery responded with a significant increase in PSV relative to rest in the dominant limb (40,50 vs 55,70, P <0,0001), and in the non-dominant one (34,96 vs 53,10, P <0,0001). There was also an increase of the eDV in the dominant limb (9,23 vs 12,61, P = 0,0046) and non-dominant (7,83 vs 11,70, P = 0,0012). The ulnar artery also presented increased PSV (44,12 vs 67,94, P <0,0001) and eDV (10,04 vs 16,82, P = 0,0001) in the dominant limb, but in the non- dominant limb there was a significant increase in PSV only (44,15 vs 63,31, P <0,0001) and not eDV (11,07 vs 13,37, P = 0,2778). There was no significant variation of resistance in both arteries and in both limbs, neither at rest nor after compression. We conclude that the flow competition may be physiological and would not entail the risk of occlusion.