Fundamental research on in vitro laser vascular-welding for aortic dissection

An in vitro experiment for the fundamental research to develop a catheter-based laser vascular-welding device used in aortic dissection was studied. We employed laser vascular-welding by means of combining diode laser irradiation and indocyanine green stain to the dissected vessel surface in a swine aortic dissection model to obtain localized heat generation. We successfully demonstrated laser vascular-welding of this aortic dissection model. The breaking strengths of the welded aortic pieces were measured. The breaking strength of 170 gf/cm2 obtained with 425 \V/cmz, 2.4 s irradiation may be strong enough for successful therapy of aortic dissection regarding the dissecting force caused by blood flow. By analyzing the reflecting and transmitting light of the diode laser from the welding section, we could monitor the progress of the welding process in the deep portion of the dissection model. A welding section temperature of approximately 300CC, which corresponds to the melting point of elastin, was estimated by thermal conduction calculation using the finite element method. From the fluorescence image of the aortic pieces, elastic fiber was observed at the dissection model surface. The mechanism of this laser vascular-welding may be based on elastic fiber entwining. We believe there is potential for this method to be applied to catheter-based therapy for aortic dissection.