How can we safely use ultrasonic laparoscopic coagulating shears?

Abstract

Purpose: To investigate changes in temperature of the tissue pad (contrary to active blade) of ultrasonic laparoscopic coagulation shears (LCS) and histological changes of tissue surrounding the pad during activation. Methods: Three types of ultrasonic LCS were assessed: SonoSurg (SSg) (Olympus, Tokyo, Japan), AutoSonix (AS) (Tyco, Pembroke, Bermuda) and Harmonic Scalpel (HS) (Johnson & Johnson, Cincinnati, OH, USA). Vibration amplitudes were 70%/100% (SSg), Level 3/Level 5 (AS) and Level 5 (HS). Durations of vibration were 5 s, 10 s, 15 s and 20 s. Changes in temperature of the tissue pad were evaluated by cutting chicken parts extracorporeally with the three types of LCS. Histological changes around the tissue pad of the SSg were evaluated in a laparoscopic porcine model. Results: At intermediate power (70% or Level 3), the SSg tissue pad temperatures were 33°C, 42°C, 55°C and 70°C, whereas the AS tissue pad temperatures were 45°C, 72°C, 80°C and 100°C. At maximum power, the temperatures of the SSg tissue pad were 38°C, 45°C, 70°C and 95°C, those of the AS were 50°C, 65°C, 70°C and 90°C and those of the HS were 49°C, 65°C, 75°C and 90°C. Histological changes occurred at 10 s, 15 s and 20 s. Conclusion: Surgeons should be aware that the temperature of the tissue pad also becomes elevated when using ultrasonic LCS. Thus, they should be concerned with surrounding tissues and organs around both the tissue pad and the active blade during activation. Regardless of the LCS type and power, a short activation time within 5 s is a safe method for using the instrument. © 2010 The Japanese Urological Association.