Er:YAG laser-assisted resection of human calcified heart valves

Background and objective: Endovascular procedures for heart valve replacement provide an alternative to open surgery. It might be necessary to remove the native valve before implantation of a new valve mounted in a collapsible stent. The aim of this study was to evaluate the feasibility of using an Er:YAG laser for the resection of human calcified valves and to quantify this process. Materials and methods: A commercially available Er:YAG laser with a specially designed fiber coupling device and fiber tip was used to cut calcified aortic and mitral valve leaflets (n=12) in vitro. Light and electron microscopic analyses of the debris were performed. Results: Cutting velocities of up to 15.3 mm per minute were achieved with an average of 7.67±4.28 mm per minute. The cutting efficiency depended on the rate of tissue calcification. The debris particle size ranged from smaller than 10 μm to 1 mm. Conclusions: Calcified heart valves can be cut using an Er:YAG laser system in vitro. Nonetheless, cutting times were rather long considering a future in vivo use of this technique.