ICG-dyed albumin and diode laser heating for soldering of the trachea

Abstract

Laser tissue soldering is a technique for the closure of incisions, which provides an immediate air-and watertight bond. Previous studies have shown that this method can bond tracheal incisions with the aid of stay sutures or solid albumin strips. In this study we investigated whether soldering using a diode laser and indocyanine green (ICG) dyed liquid albumin solution as solder, was efficacious for the repair of tracheal incisions without the need for additional strengthening aids. A transverse incision was made in isolated pig tracheas. The incision was smeared with liquid solder composed of 42% bovine albumin and 0.1 mg/ml ICG, and soldered using a temperature-controlled fiberoptic diode laser system. The soldered tracheal ends were sealed and the burst pressure measured. In a series of experiments the burst pressure was found to be higher than 382 mm Hg. These preliminary results demonstrate that diode laser tissue soldering of tracheal incisions provides better results than with a CO2 laser, and that it is possible to achieve considerable soldering strength without the use of any additional strengthening procedures.

Laser Soldering of Cartilage Graft Interposed Into a Tracheal Incision in a Porcine Model

“…These results, however, were inconsistent, with measurements as low as 102 mm Hg. These results were found to be significantly poorer than those of the previous study by Shapira et al, in which a single incision in a porcine trachea was soldered with an indocyanine green–dyed liquid albumin solution.…”

“…Laser soldering of tissue allows for dissipation of the heat energy through the solder material, so the heat energy in the tissue is lower, reducing the risk for thermal damage. Furthermore, some of the mechanical strength of the bond may be attributable to the coagulated solder . Irradiation of the solder produces a temperature gradient throughout the solder that is dependent on the absorption coefficient and the thermal conduction coefficient of the solder, which leads to difficulty in predicting the temperature at the tissue–solder interface …”

“…The albumin solder on the incision edges and between them was heated continuously to 60°C, 70°C, 80°C, and 90°C, according to the assigned group, along the circumference with a diode laser until coagulation was seen in the albumin. Heating the solder to 70°C is equivalent to achieving 65°C at the solder–cartilage interface . The laser soldering procedure was carried out under 10× magnification of a microscope.…”

“…While coughing, the air pressure in the trachea can reach 300 mm Hg . Air leak has been reported in up to 15% of cases, leading to inflammation and possibly causing recurrent stenosis. Posterior graft LTP can be performed endoscopically in a technique that does not require sutures .…”

“…Sharvit et al successfully soldered an incision in a pig trachea, using CO 2 laser and solid albumin strips, to withstand a mean burst pressure of 230 mm Hg . Shapira et al used a galium‐arsenide (GaAs) diode laser with liquid albumin solder on an incision in a pig trachea to withstand a burst pressure of 382 mm Hg in 12 specimens . These studies demonstrate the feasibility of laser soldering of laryngotracheal cartilage tissue.…”