Effects of diode laser welding with dye-enhanced glue on tensile strength of sutures commonly used in urology

Background and Objective: Tissue welding using laser-activated protein solders may soon become an alternative to sutured tissue approximation. In most cases, approximating sutures are used both to align tissue edges and provide added tensile strength. Collateral thermal injury, however, may cause disruption of tissue alignment and weaken the tensile strength of sutures. The objective of this study was to evaluate the effect of laser welding on the tensile strength of suture materials used in urologic surgery. Study Design/Material and Methods: Eleven types of sutures were exposed to diode laser energy (power density = 15.9 W/cm ²) for 10, 30, and 60 seconds. Each suture was compared with and without the addition of dye-enhanced albumin- based solder. After exposure, each suture material was strained (2''/min) until untimate breakage on a tensometer and compared to untreated sutures using ANOVA. Results: The strength of undyed sutures were not significantly affected; however, violet and green-dyed sutures were in general weakened by laser exposure in the presence of dye-enhanced glue. Laser activation of the smallest caliber, dyed sutures (7-0) in the presence of glue caused the most significant loss of tensile strength of all sutures tested. Conclusion: These results indicate that the thermal effects of laser welding using our technique decrease the tensile strength of dyed sutures. A thermally resistant suture material (undyed or clear) may prevent disruption of wounds closed by laser welding techniques.