High-intensity Focused Ultrasound In Interventricular Septal Myocardial Ablation: Effects Of Coronary Flow

Abstract Background High-intensity focused ultrasound (HIFU) can generate necrotic damage in deep tissues through thermal ablation and cavitation, without significant damage to the surrounding tissues. The high blood perfusion of heat affects the deposition of energy. The aim of this study was to evaluate the effect of cooling of coronary blood flow for high-intensity focused ultrasound ablation. Methods Continuous and pulsed HIFU (2000 J) at duty cycles (DCs) of 100% and 20% were examined for their capacity to ablate the perfused porcine heart tissue in vitro. After ablation, gray scale changes and pathological features were observed or measured, and tissue necrosis area and volume were calculated. Results The cardiomyocytes in the lesions underwent necrosis with a clear boundary. The endocardium was intact without necrosis. The three-dimensional morphology of the lesions appeared approximately as ellipsoids. With the increase of perfusion speed, the necrotic volume in the target area was gradually reduced. Conclusions HIFU has the potential to become a new minimally invasive surgery for ventricular septal myocardial ablation. Reducing coronary blood flow can improve the ablation effect.