Welding artificial biomaterial with a pulsed diode laser and indocyanine green dye

Laser tissue welding is a sutureless method of wound closure that has been used successfully in nerve, skin, and arterial anastomoses. We welded an elastin-based biomaterial that elicits minimal foreign body reaction to the intimal surface of porcine aorta. 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 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 4-20 N/cm² for 5 ms pulse durations and 83 mJ/mm² radiant exposure. Welds were successful for pressure above 5 N/cm². Transmission measurements of stained aorta were made using radiant exposures of 6-129 mJ/mm² using pulse durations of 0.5-5 ms. Transmission increases and reaches a maximum of 80-85% with successive pulses for radiant exposure greater than 26 mJ/mm² for a spot size of 9 mm² and 13 mJ/mm² for a spot size of 36 mm².