Comparative In Vitro Study of Tissue Welding Using a 808 nm Diode Laser and a Ho:YAG Laser

Abstract.

In vitro porcine arteries and veins have been welded end-to-end using either a 808 nm diode laser combined with an indocyanine green enhanced albumin solder, or with a continuous-wave (cw) Ho:YAG laser without biological solder. The vascular stumps were approached to each other over a coronary dilatation catheter in order to obtain a precise alignment and good coaptation. Standard histology revealed for both welding techniques lateral tissue damage between 2 and 3 mm caused by laser-induced heat. Good solder attachment to the tissue was observed by the use of a scanning electron microscope. The vessels soldered with the 808 nm diode laser using albumin solder showed considerably higher tensile strength (1 N compared to 0.3 N) than vessels welded exclusively by Ho:YAG laser radiation. In contrast, leaking pressure (350±200 mmHg) and bursting pressure (457±200 mmHg) were found to be independent of the welding technique used. This study demonstrates that fast (total welding time about 2–5 min), stable and tight microvascular anastomosis can be achieved with the use of a dye-enhanced albumin laser soldering technique and an ancillary coronary dilatation catheter.