The Exploration Of Ho:yag Laser Output Power In Cardiac Valvoplasty:an In Vitro Study

Objective To investigate the Optimal output power of Ho:YAG laser for cardiac valvoplasty.Methods 1. 30 pieces of mitral valve from patients with Rheumatic Heart Disease were divided into three groups according to the output powers of Ho:YAG laser: Groupâ‘ 10watts,Groupâ‘¡15watts, Groupâ‘¢20 watts.Each group had 10 pieces.2. Calcified plaque and thickened fibrous tissue were removed with the Ho: YAG laser.3. The histomorphology of valves before Ho: YAG laser irradiation was analyzed using hematoxylin-eosin (HE) staining and scanning electron microscopy, and using HE staining, masson staining and scanning electron microscope after Ho: YAG laser irradiation,Results 1. HE staining: Before the laser irradiation, the cardiac valve was proliferated, degenerated mucoidly and calcificated focally; after the laser irradiation, the focal pathological calcification was basically eliminated, and the cardiac valve surface was uneven.2. Masson staining: The valve surface was uneven and rough and the collagen fiber was exposed after the cardiac valvoplasty.3. Scanning electron microscope: before the cardiac valvoplasty, the cardiac valves had many calcified plaques on the surface; after the cardiac valvoplasty, the great majority of calcified plaques on the valves surface were disappeared, the endothelial cells were damaged and the collagen fibers were exposed.4. Valvoplasty effects according to different output powers of Ho:YAG laser: Groupâ‘ :most of the calcified plaques on the surface were removed and same calcified plaques were still residual, the cardiac valves surface was uneven, some collagen fibers were exposured, Groupâ‘¡:the cardiac valve calcification patchs were basiclly cleared, the valves surface was more flat and had some laser cut pit,and many collagen fibers were exposured, Groupâ‘¢: the Cardiac valve calcification plaques were basiclly cleared, the cardiac valve surface was uneven and rough and had more laser cut pit, more collagen fibers were exposed .Conclusions The cardiac valvoplasty was safe and effective with the output power 15 watts of the Ho: YAG laser.