Dye-enhanced protein solders and patches in laser-assisted tissue welding

This study examines the use of dye-enhanced protein bonding agents in 805 nm diode laser-assisted tissue welding. A comparison of an albumin liquid solder and collagen solid-matrix patches used to repair arteriotomies in an in vitro porcine model is presented.

Extrinsic bonding media in the form of solders and patches have been used to enhance the practice of laser tissue welding. Preferential absorption of the laser wavelength has been achieved by the incorporation of chromophores.

Both the solder and the patch included indocyanine green dye (ICG) to absorb the 805 nm continuous-wave diode laser light used to perform the welds. Solder-mediated welds were divided into two groups (high power/short exposure and low power/long exposure), and the patches were divided into three thickness groups ranging from 0.1 to 1.3 mm. The power used to activate the patches was constant, but the exposure time was increased with patch thickness.

Burst pressure results indicated that solder-mediated and patched welds yielded similar average burst strengths in most cases, but the patches provided a higher success rate (i.e., more often exceeded 150 mmHg) and were more consistent (i.e., smaller standard deviation) than the solder. The strongest welds were obtained using 1.0-1.3 mm thick patches, while the high power/short exposure solder group was the weakest.

Though the solder and patches yielded similar acute weld strengths, the solid-matrix patches facilitated the welding process and provided consistently strong welds. The material properties of the extrinsic agents influenced their performance.