Cooled-tip diode laser catheter for improved catheter ablation of XXXX .

@entity1165 @entity39 @entity235 @entity406 @entity715 @entity943
Catheter ablation for the treatment of @entity943 has evolved dramatically over the past two decades. Researchers have investigated alternative energy sources and catheter constructs to improve the efficacy and safety of catheter ablation. This study tested the hypothesis that a new prototype cooled-tip laser catheter used with a low-power diode laser would improve catheter ablation of @entity1165 . Four mongrel @entity235 underwent a median sternotomy. The cooled-tip laser catheter was advanced into the left ventricle via the left carotid artery and positioned adjacent to the endocardium. Laser powers of 3 and 4 W were delivered at four exposure times to select areas of the endocardium. During application of laser energy, room-temperature saline was circulated through the catheter. At necropsy the hearts were examined and fixed in @entity406 for histologic examination. Gross examination of the endocardial surfaces showed no indication of crater or @entity715 formation. Cross-section of the lesions revealed sharply demarcated, circular-shaped areas of coagulative @entity39 extending into the mid-myocardium. Areas of coagulative @entity39 were identified within the myocardium extending into the mid-myocardium and occasionally the subepicardium. A sharp line of demarcation was observed between the lesions and the surrounding normal myocardium. The results of this study showed that we could use surface cooling during slow laser heating to create large subsurface lesions with characteristics appropriate for treatment of @entity1165 and little to no surface damage. We believe our catheter system addresses many of the previous issues with laser-based approaches.
