Reduction of Thermal Spread and Tissue Adherence with an Irrigating Bipolar Grasper

Bipolar energy heats tissues and leads to thermal spread beyond the target tissues. As temperatures rise above 70° C, tissues stick to the metal jaws of the graspers. The use of irrigating fluid while applying the energy should reduce these effects by cooling the surrounding tissues, and also permit the surgeon to clear the operative field of blood. An in vivo animal study was performed to measure these effects. Energy was applied to porcine uterine horn with and without irrigation with a new irrigating bipolar grasper. Lateral thermal spread and tissue adherence were measured. Tissue was excised and thermal spread measured grossly and microscopically. Results are shown in the table. Without irrigation, thermal spread stops at 10 seconds due to complete desiccation of the tissues. Lateral thermal spread is reduced below 10 seconds with irrigation, but it continues to rise as energy is applied. Coagulated tissues adhered to the grasper jaws in all of the nonirrigated tests. Cooling the jaws with irrigation eliminated this. The ability to irrigate through the bipolar grasper improves the surgeon's efficiency by reducing tissue sticking, and adds control by reducing thermal spread during normal application of energy.