Abstract: Tissue sticking upon the active electrode of electrosurgical unit during electrosurgery increases the electrical resistance of electrode and hinders the energy delivery to targeted tissue, then reducing operation efficiency and accuracy. PTFE-coated electrode has been used as anti-sticking electrode in clinic due to low surface energy recently, but little is known about its incision efficiency and anti-sticking durability. The incision resistance of PTFE-coated electrode-tissue interface is measured in a real time during the electrosection cutting process of ex vivo fresh porcine liver tissue, the morphologies of electrode surface are studied using various microscope examinations, and the tissue damage is examined with histotomy, aiming to reveal the variations of the incision efficiency and anti-sticking performance of PTFE-coated electrode with operation time. Results show that there existed an inverse correlation between the incision efficiency and anti-sticking performance of PTFE-coated electrode. In the initial stage of electrosection cutting, the electrode surface is coated totally with a layer of PTFE and had obvious anti-sticking effect, the thermal damage of liver tissue is slight, but the incision resistance is big, that is, the incision efficiency is low. With the cutting time increasing, the PTFE coating is thinned and punctured locally by arc ablation, the incision resistance reduced significantly, but the anti-sticking effect decreased obviously and the tissue thermal damage is aggravated. As the cutting proceeded further, the PTFE coating is totally destroyed and then its anti-sticking effect did not work. The incision resistance is increased to the minimum. Increasing the output power of electrosurgical unit increased the incision efficiency of PTFE-coated electrode, but the damage of PTFE coating is speeded up so as to shorten its anti-sticking durability remarkably and aggravate the tissue thermal damage. In sum, PTFE coated electrode had a low incision efficiency and inferior anti-sticking durability under the complex electrosurgical condition.

Key words: anti-sticking performance, electrosurgical unit, incision efficiency, PTFE-coated electrode, tissue sticking