Patch welding with a pulsed diode laser and indocyanine green

Laser tissue welding is a sutureless method of wound closure that has been used successfully in nerve, skin and arterial anastomoses. An elastin-based biomaterial patch was welded to the intimal surface of porcine aorta in the present study. The aorta was stained with indocyanine green dye to efficiently absorb the 808 nm diode laser light. Laser welding with a pulsed diode laser thermally confines heating to the stained portion of tissue, minimizing adjacent tissue damage. Laser welds of stained aorta to biomaterial were attempted by sandwiching the samples between glass slides and applying pressures ranging from 4 to 20 N cm(-2) for 5 ms pulse durations and 83 mJ mm(-2) radiant exposure. Bleaching of the indocyanine green by as much as 85% was observed after exposure laser irradiation. Finally, successful welds required 5 N cm(-2) of pressure between the elastin biomaterial and aorta.