Laser vascular welding

Vascular tissue fusion by lasers is performed by directing a low energy beam at the apposed edges of the repair. The tissues are approximated with stay sutures or non-reflective instruments and laser energy is passed back-and-forth over the anastomotic site until fusion is achieved. Vessel welding is apparent to the trained eye, as is nonunion caused by inadequate energy delivery. Conversely, excessive energy delivery results in obvious tissue coagulation or vaporization. Fiberoptic laser transmission and hand-eye coordination are adequate for repair or anastomosis of vessels with diameters greater than 3 mm, whereas magnification and precise mechanical control of the laser beam are necessary for microanastomoses of smaller vessels. The laser power (watts, W), and the amount of energy and time required (energy fluence or power density) vary according to the type of laser and the size of the vessels. Although laser repairs can be fashioned in time intervals equal to or slightly longer than those required for suture repairs, the optimum wavelengths and laser parameters for different types of seals are not yet established.