Experimental Investigation and Modeling of Catheter Temperature in Atherectomy
Atherectomy, which is generally featured by a high-speed grinding, is a common intervention process to treat atherosclerosis and simultaneously restore the blood flow. The friction, generated among the rotational drive shaft, the stationary sheath, and guidewire in the catheter, usually causes the blood temperature rise, which may result in the thermal damage to the artery tissue. This paper is devoted to investigating the catheter temperature in atherectomy. In this study, experiments were conducted to investigate the effects of rotational speed, saline flow, and catheter curvature on the catheter temperature rise. A thermal model to calculate the temporal and spatial distribution of catheter temperature rise was developed to predict the potential thermal damage and the safety interventional parameters in atherectomy. The catheter temperature increases with the time, the length of the catheter, and rotational speed. The curvature induced catheter temperature rise is less than 0.3 °C, which is negligible. Temperature rise under the clinical condition can potentially reach 12 °C at 175,000 rpm. The proposed thermal model can be used to predict the saline temperature within a variation of 0.4 °C. The heat generated in the catheter may cause potential thermal damage to the blood and artery tissues in atherectomy. Furthermore, the safety process time is less than 6 s and safety minimum saline flow rate is 33 ml/min under all recommended rotational speeds. Increasing the saline flow rate is a method to reduce the temperature rise effectively and lower the thermal damage to blood and tissues.