Comparison of thermal spread after ureteral ligation with the Laparo-sonic™ ultrasonic shears and the Ligasure™ system

Background and Purpose: The extent of lateral spread of tissue injury is important in the success of a primary anastomosis. We compared the injury produced by the Laparo-sonic(TM) Coagulation Shears and the Ligasure(TM) system. Materials and Methods: Ureters were harvested from domestic farm pigs and ligated with the Laparo-sonic (N = 13) or Ligasure (N = 9) system. The tissues were then fixed, stained, and examined by two pathologists without knowledge of the type of treatment. Results: The mean length of thermal damage from the Ligasure was 2.11 nm (range 1.0-4.0 mm) whereas it was 1.92 (range 0.5-4.25 mm) from the Laparo-sonic system. The difference is not statistically significant. Conclusion: Debridement of as much as 5 mm of each cut end produced by the Laparo-sonic or Ligasure system may be beneficial in reducing stricture and leak.