Application of CO2 laser in improving mechanical performance of surgical knots

Most surgeries depend on the use of synthetic sutures for approximating tissues, transplanting organs, and implanting prosthetic devices. Although the properties of suture materials have significantly improved compared to their natural predecessors, a problem of great concern still remains which is the slippage of knot. An in-depth study was undertaken and is reported in this paper. It includes tests on different types and sizes of sutures, exposed to laser radiation of different levels under controlled conditions. Two focuses of the study were conditions under which optimum results were obtained and the mechanisms that governed the changes in the performance of the sutures. The experiments conducted were on sutures of four different types (multifilament braided polyester, polypropylene, nylon and polyglycolic acid and monofilament polypropylene) and three different sizes (1-0, 3-0 and 5-0). The tensile test results of the knotted samples showed that in sutures in which a two throw square knot was initially secure (polyglycolic acid) little or no increase in tensile strength occurred with exposure. However, in the sutures in which the knot readily slipped polypropylene, polyester, and nylon) the strength and security of the knot could be significantly increased and optimized