EFFECT OF LOW-GRADE RADIOFREQUENCY HEATING ON ARTERIAL VASOSPASM IN THE PORCINE MODEL

Nineteen pigs were studied in order to assess the effect of low grade, radiofrequency-powered, thermal balloon angioplasty on the vasoconstr ictor response of peripheral arteries, A mechanical stimulus was used to induce vasospasm, Thermal angioplasty reduced the extent of inducib le vasospasm from 79% to 6% compared to nonthermal control inflations, which reduced the vasoconstrictor response from 75% to 60% (P < 0.001 ), Histologic studies demonstrated that the extent of myocyte necrosis was significantly greater in the thermally treated arteries than in t he control vessels (P < 0.01), Thermal balloon angioplasty at 60 degre es C significantly attenuates peripheral arterial vasospasm induced by mechanical trauma in the porcine model. This paralytic effect may be related to the lass of myocytes secondary to thermal necrosis. (C) 199 7 Wiley-Liss, Inc.