A Study on Vessel Wall Shrinkage and Tissue Damage of Compressed Vascular Using Therapeutic Ultrasound

Abstract--Ultrasound therapy has been proven to be a method of ablating diseased blood vessels. Currently, experiments have proven that external pressure on the vascular region to be treated can effectively improve the success rate of closure. However, the degree of resulting thermal damage to surrounding tissue and the reason for the effects of compression on the shrinkage of tissue-encased blood vessels remain unclear. To address this issue, we conducted a study comparing the rate of shrinkage and surrounding tissue damage of compressed vessels encapsulated in muscle tissue to vessels with normal blood flow before and after treatment using the Simulation experiment and the ex-vivo tissue experiment. The results show that in the simulated model of compressed blood vessels with static blood flow, the temperature rise is significantly higher compared to the model with simulated blood flow. In the ex-vivo tissue experiment, the shrinkage rate of the blood vessel with static blood flow reaches up to 57% after the treatment, while the area of thermal damage is 28.8mm$^{2}$. In contrast, in the blood vessel with flowing blood, the vessels undergo almost no shrinkage but still cause 5.16mm$^{2}$ of thermal damage to the surrounding tissue. Our findings confirm that compressing the vessel is an effective and necessary step for the ultrasound closure of the vessel. But at the same time, to alleviate additional thermal damage, trying to change the way and position of the compression during treatment may be necessary.