eComment: Is the inner diameter of radial artery reliable for its suitability as a graft?

removal of the radial artery for myocardial revascularization: a Doppler study to prevent ischemic complications to the hand. Assessment of the radial artery and hand circulation by computed tomography angiography: a pilot study. According to your study w1x, one of the contraindications for radial artery harvesting is its small inner proximal and distal diameter, smaller than 2 mm (Tables 2 and 3 of the above study). This consideration is arbitrary and undocumented. The inner instantaneous diameter of the radial artery is the result of a dynamic and sensitive process, depending on the instantaneous vascular tone respectively. Especially for muscular type arteries such as radial, the vascular tone is very variable. On the contrary, large arteries modify their blood flow by increasing or reducing their internal diameter. Such a flow-dependent dilatation represents a fundamental mechanism that opposes the equivalent neurogenic and myogenic mechanisms that are activated during exercise vasoconstriction; in order to maintain sheer stress within physiological levels w2x. Factors such as the environmental temperature, muscular exercise, post-ischemia hyperemia, levels of endogenous or exogenous catecholamines, a-agonists, and heart failure result from time to time in a continuous variability of the radial diameter and wall thickness/diameter ratio. Giannattasio et al. w3x demonstrated that congestive heart failure (CHF) is characterized by a reduction of the inner diameter of muscular arteries, which is proportionally related too the severity of the disease. In addition, Boutouyrie et al. w4x reported that the radial artery in hypertensive patients was not dilated but was with a thicker wall, compared to the normotensive population. Thus, the wall cross-sectional area and wall/lumen ratio were markedly increased in hypertensive patients, factors that indicated the normalization of circumferential wall stress. In conclusion, in patients with coronary artery disease (CAD) and simultaneously left ventricular dysfunction, or with hypertension, the estimation of the inner diameter of the radial artery may lead to false rejection of radial artery suitability as a graft ('false – unsuitable'). Luescher T. Nitric oxide is responsible for flow-dependent dilatation of human peripheral conduit arteries in vivo. and aortic distesibility in congestive heart failure: effects of high-dose angiotensin-converting enzyme inhibitor of low-dose association with angiotensin type-1 receptor blockade. Association between local pulse pressure, mean blood pressure, and large-artery remodeling. We were reading the study performed by Kohonen et al. w1x with great interest and congratulate the authors for the additional research on radial arteries. The results give us some hints to …