How can we safely use ultrasonic laparoscopic coagulating shears?

Area of Science:

• Laparoscopic surgery
• Surgical instrumentation
• Biomedical engineering

Background:

• Ultrasonic laparoscopic coagulation shears (LCS) are widely used in minimally invasive surgery.
• Understanding thermal spread from these devices is crucial for patient safety.
• The tissue pad, distinct from the active blade, can also generate heat during LCS activation.

Purpose of the Study:

• To quantify temperature changes in the tissue pad of ultrasonic LCS during activation.
• To evaluate histological alterations in surrounding tissues near the tissue pad.
• To compare thermal profiles of different LCS models.

Main Methods:

• Three ultrasonic LCS devices (SonoSurg, AutoSonix, Harmonic Scalpel) were tested at varying power levels and durations (5-20 seconds).
• Tissue pad temperatures were measured during extracorporeal chicken tissue cutting.
• Histological changes around the tissue pad were assessed in a porcine laparoscopic model using the SonoSurg device.

Main Results:

• Tissue pad temperatures increased with activation duration and power, reaching up to 100°C.
• Significant histological changes in surrounding tissues were observed after 10 seconds of activation.
• All tested LCS models showed temperature increases, with variations based on device and settings.

Conclusions:

• Surgeons must be aware of and account for heat generated by the tissue pad of ultrasonic LCS.
• Careful consideration of surrounding tissues and organs near both the active blade and tissue pad is essential.
• Utilizing short activation times (≤5 seconds) is a recommended safe practice, irrespective of LCS type or power setting.