EFFECT OF THE CO2 MILLIWATT LASER ON TENSILE-STRENGTH OF MICROSUTURES

Background and Objective: Laser-assisted tissue repair is often accomp anied by a high dehiscence rate, which may be due to alterations in su ture material after laser exposure. The goal of this study was to inve stigate the effect of CO2 laser irradiation on the tensile strength of microsurgical suture material. Study Design/Materials and Methods: 10 -0 nylon and 25 mu m stainless steel threads were exposed to 12 combin ations of power densities (62, 124, and 186 W/cm(2)) and pulse duratio ns (0.5, 1, 2, 3 s) and tested on a tensometer for their tensile stren gth. Results: At power densities of 186 W/cm(2), the 10-0 nylon thread disrupted during laser irradiation, regardless of pulse duration. Thi s was also the case at power densities of 124 W/cm(2) for 2 s and 3 s pulse duration. At 124 W/cm(2) for 0.5 and 1 s, the tensile strength d ecreased with 70% relative to the control, At 62 W/cm(2), the tensile strength gradually decreased from 100% (0.5 s pulse duration) to 50% ( 3 s pulse duration) relative to control. Stainless steel thread resist ed all laser irradiations. Conclusions: The 10-0 nylon thread is signi ficantly compromised by irradiation with the CO2 milliwatt laser and t herefore meticulous care should be taken not to irradiate the sutures during laser tissue welding. (C) 1997 Wiley-Liss, Inc.