Laser welding: an alternative method of venous repair

This study compared the histology, biochemistry, tensile strength, and extensibility of Nd:YAG laser-welded and sutured venotomies. Two-centimeter-length bilateral canine femoral or jugular venotomies were evaluated with one vessel (control) closed with interrupted 6-0 polypropylene sutures, and the contralateral vessel (experimental) welded with the Nd:YAG laser (1 W power and 30- to 40-sec exposure). Specimens were removed and examined immediately after fashioning (t0) and at 1, 4, or 5 weeks post-operatively to compare the progression of healing. Histologic examination of the 4- and 5-week sutured wounds had granulomatous reaction around the sutures with areas of excessive collagen accumulation. In contrast, the laser-welded wounds had minimal inflammatory response, near normal collagen content, and minimal residual disorientation and break in the elastic fiber continuity. The rate of collagen synthesis in laser-welded wounds was approximately twice that of sutured wounds at 1, 4, and 5 weeks, and correlated with increased tensile strengths of lasered wounds. The extensibility of the 5-week specimens was 0.19 for sutured and 0.29 for laser-welded wounds as compared to 0.29 for normal vein. These preliminary data suggest that laser welding of venotomies may have several advantages over conventional suture techniques.