Controlled bipolar high-frequency coagulation for transurethral application: a new method for the destruction of urinary bladder tumors.

The coagulation of small bladder papillomas or of the resection base after transurethral resection by unipolar high-frequency current has turned out not to be sufficiently radical so far. There is no definite and reproducible correlation between the achieved biological effect. Bipolar high-frequency current produces the desired necrosis in the deeper layers of tissue. When providing the high-frequency generator with a new experimental automatic control equipment, reproducible deep and homogeneous necrosis of the tissue can be achieved without taking a great deal of time. Moreover, adherence of the probe and carbonization are prevented. First, the experiments had been carried out in vitro on livers of cattle and secondly, in vivo on canine livers. By the conventional unipolar high-frequency coagulation a reproducible and homogeneous necrosis cannot be achieved. With the regulated high-frequency coagulation, however, we are able to produce homogeneous tissue necroses up to a depth of 7 mm, the extension of which can definitely be assigned to the adjusted technical parameters. The electrodes do not adhere, since carbonization does not occur because of the automatic control. Premature interruption of the coagulation process, even if the generator is adjusted too high by mistake, can be considered a further advantage of this protective switch. A first clinical experience is reported.