In vivo effect of 5 French bipolar and monopolar electrosurgical probes on the porcine bladder.

Previous in vitro studies have indicated bipolar electrosurgical probes would electrodesiccate tissue in a normal saline solution. This study applies similar sized monopolar and bipolar electrosurgical probes to porcine bladder in order to compare each probe's effect in vivo. The power delivered by each probe was calculated; the width and depth of the porcine bladder damage was measured and the volume of the damage calculated. The animals were sacrificed at 24, 48 and 96 h post-procedure so that the amount of tissue destruction could be quantitated relative to the bladder's natural tissue reaction. The data shows the power (watts) delivered by the monopolar probe to be approximately six times that of the bipolar probe. Likewise, the area of bladder wall damage was larger with monopolar at all time periods sampled and showed significant differences at 24 and 48 h. These studies indicate that in viable bladder, tissue bipolar probes will electrodessicate at a lower power and with less shortterm tissue damage.