Recently, the coagulation method instilling saline on active electrodes of electrosurgical generators with SOFT Coagulation has been used. This study verified what change this method brings.
Followings were used: VIO300D(ERBE) / electrosurgical generator, EIP2(ERBE) / irrigation pump, ball-type IO-advance electrode / active electrode, physiological saline, and porcine liver. Output mode was SOFT Coagulation (80W/E5), with the activation time of 3, 6, 9, and 12 seconds for with/without saline instillation. Saline instillation rate was set to one drop (0.05ml) per one second. The output was repeated 5 times respectively, and the mean values of diameter and depth were calculated from the obtained data.
In each output time, without instillation, mean coagulation diameters were 7.4/8.8/9.6/9.6mm and mean depths were 1.2/2.3/2.4/2.6mm. In output time of 9 seconds or longer, tissue adherence on the electrode was observed with little difference in coagulation diameter and depth. With instillation, mean coagulation diameters were 1.6/12.2/14.0/16.4mm, and mean depths were 0.3/2.5/3.6/7.0mm without tissue adherence.
Without instillation, as tissue coagulation progresses, resistance value is increased. Therefore, even in long time output, variation of diameter and depth becomes limited. Whereas, with instillation, the diameter and depth are increased due to the broadened range of current flow.
