Diode laser vascular welding of swine aorta under scattering light monitoring

To develop the catheter-based laser vascular welding device against aortic dissection, we studied fundamental characteristics of the laser vascular welding for aorta dissection model in vitro with the scattering light monitoring to obtain welding proceedings. We employed the laser vascular welding by means of the combination of the diode laser irradiation and indocyanine green (ICG) stain to the dissected vessel surface in a swine aortic dissection model to obtain localized heat generation on the surface. The forward and backward scattering lights of the diode laser from the welding portion were measured during the laser irradiation. The breaking stresses of the welded aortic pieces were measured. The breaking stress of 170gf/cm 2 obtained with the 425W/cm 2 , 2.4s irradiation may be strong enough to the successful therapy for aortic dissection regarding to the dissecting force caused by blood flow. By analyzing forward and backward scattering lights, we could observe the occurrence of water evaporation in the welding portion, the bleaching of the ICG and the carbonization of the welding portion. Then we could monitor the proceedings of the welding process. The temperature estimation of the welding portion and the microscopic observation revealed that the mechanism of our welding may be basically elastic fiber entwining. We think our vascular welding with the scattering light monitoring of the welding process has the potential to apply catheter-based therapy for aortic dissection.