ACUTE EFFECTS OF PERIARTERIAL SYMPATHECTOMY ON THE CUTANEOUS MICROCIRCULATION

The clinical effects of peripheral sympathectomy; on patients with vas o-occlusive disease are often dramatic and include relief of pain, imp roved quality of life, and healing of ulcers, Peripheral periarterial sympathectomy is known to increase skin temperature and to maximize th e nutritional component of peripheral blood flow, but the pathophysiol ogy of vaso-occlusive disease and the physiologic mechanisms of this t reatment sue unknown. In this study, the acute effects of periarterial sympathectomy were directly observed in a rabbit ear model of digital microcirculation (arterioles arteriovenous anastomoses, and venules). The effects of periarterial sympathectomy on cutaneous perfusion and total flow were also examined using laser Doppler perfusion imaging an d digital temperature measurements. The central auricular artery becam e dilated (50-100%) immediately after sympathectomy; the arterioles, a rteriovenous anastomoses, and venules dilated to 165, 156, and 223%, r espectively, at 30 minutes and to 187, 174, and 204%, respectively, at 60 minutes, relative to their baseline diameters prior to sympathecto my. Laser Doppler perfusion imaging values and ear temperatures were n oted to Increase after sympathectomy (8.9%, 3 degrees C), although the core temperature of the rabbit did not change. Thus, acute periarteri al sympathectomy can (a) effectively reduce the vascular tone of the d istal microvasculature and (b) increase total microcirculatory perfusi on - cutaneous and thermoregulatory by both venular and arteriolar dil ation. Periarterial sympathectomy has the clinical potential to increa se nutritional blood flow, thereby ameliorating the signs and symptoms of ischemia associated with thermoregulatory abnormalities. Dilation of the arteriovenous anastomoses, with a subsequent reduction in vascu lar resistance, may contribute to the increased cutaneous temperature noted after sympathectomy.