Abstract
To evaluate the mechanical factors that determine ablation depth rate in vivo, we studied samples of canine aortas in a model system. The segments of atherosclerotic arteries were irradiated using a 308nm XeCl excimer laser energy delivered through a fiberoptic that was held in constant contact with the tissue.
The effect of the mechanical factors, such as the applied pressure and laser pulse repetition rate, on the ablation depth rate was studied. The ablation depth rate was found to depend on applied pressure and laser pulse repetition rate. That is, the ablation depth rate increased as applied pressure and laser pulse repetition rate increased. No effect of the laser pulse repetition rate on ablation depth rate was observed when the tissue was irradiated by a focused bare beam (applied pressure=0). Histological finding suggested that a mechanical tearing of tissue occurs.
Conclusion: Our study suggested that in a clinical setting, not only a laser energy but also the mechanical factors such as the applied pressure and laser pulse repetition rate affected the ablation depth rate.
