Hemodynamics of Endoscopic Imaging of Chronic Total Occlusions

Abstract

This thesis investigates the fluid dynamics of saline flushing in endovascular catheters used in the treatment and diagnosis of chronic total occlusions (CTOs) in arteries. Using computational fluid simulations different designs of catheters are studied to understand and optimize parameters involved in flushing blood from the lumen space between the catheter tip and the CTO. Simple injection catheters are studied initially, and, in the interest of improving the catheter functionality, design modifications are made to the catheter. A suction lumen is introduced and its influence is investigated while testing different shapes and relative locations of the two lumens (injection and suction) in the catheter. The simulations are improved by introducing a pulsatile external blood pressure from the heart beat, different arterial radii and curvature in the artery to explore the different physical phenomena that could affect the performance of the catheter. Various plaque buildup and morphologies are investigated to test the viability of the catheter design. A new and improved method of saline injection, suction and control, which helps avoid risk of catheter failure and injury to the patient, is proposed. An optical analysis is performed to provide confirm clearance of blood obtained in simulations. Analyzing the physical variables involved in the medical procedure, such as injection pressure and time to clear the lumen for optical transparency, as done in this thesis, helps recommend new and improved designs for catheters and can be used to reduced risk and improve success rates associated with the technique.