It is difficult to precisely predict the effects of electrical energy on tissue in the clinical setting. Many variables have the potential to affect results in electrosurgery. Because many of these parameters are not detailed by investigators, it is difficult to interpret differences in results reported in electrosurgical studies.
To understand electrosurgery, it must be clear that the effects obtained are the result of heat. This heat may be derived from an external source and transmitted to tissue by conductance (cautery), or, as in the case of both laser and electrosurgery, be produced within the tissue by an external source of energy. Due to the rapid changes in the direction (polarity) of current flow with the use of high frequency alternating current, there is no net transfer of electrons, and likewise, no movement of ions across cell membranes (depolarization). Part of the heat generated is from the tissue's impedance (resistance to current flow), but the majority of heat stems from the rapid vibration of molecules within the tissue under the effect of the changing electromagnetic field. That there is no essential difference in the effect of heat produced by any method was demonstrated by Lounsberry and associates,1 who were unable to detect any difference in tissue effect between cutting and coagulating currents of the same amperage, applied over the same area and for the same duration. Indeed, lesions produced by a soldering iron (cautery) were similar to electrical lesions. These findings were confirmed by Zervas and Kuwayama2 who found that lesions produced in rat brain and liver by induction heating, radio frequency electrocoagulation, and direct application of heat were similar for similar degrees of temperature elevation. The only application in which there may be a difference in both mechanism and effect is cutting with electrical current.
Although numerous electrosurgical tissue effects have been described and named, we can find evidence to justify defining only two effects by histologic changes (desiccation and coagulation) and two by observed surgical effects (fulguration and vaporization, commonly called cutting). We will briefly discuss each of these effects.
Jinhua Huacheng Medical Appliance Co.,Ltd.
Manufactuer of disposable medical products: Electrosurgical pencil,grounding plate,skin stapler and ECG electrode
