Ablation of bull prostate using novel bipolar radiofrequency ablation probe.

PURPOSE: We describe the use of a novel bipolar radiofrequency (RF) system for the destruction of prostate tissue in an ex vivo model.

MATERIALS AND

METHODS

A bipolar RF delivery system (Trod Medical, France) was linked to a 500 kHz generator. Eight lesions were created in an ex vivo bull prostate model using 7-mm (n = 4) and 10-mm probes (n = 4). Ablation was performed for 150 seconds. Temperature was recorded at the center of the lesion (Tc) and at the periphery (Tp) of the prostate. Tissue damage, both within and without the intended destruction zones, was assessed. The distance from Tc to Tp was recorded.

RESULTS

All lesions created with either the 7-mm or 10-mm bipolar RF ablation (RFA) probes demonstrated complete tissue destruction only within the intended zone. Using the 7-mm probe, the mean Tc was 82 degrees C and the mean Tp 34 degrees C. The mean distance from the edge of the lesion to the periphery was 5 mm. Impedance was 62 Ohm, and power was 4 watts during ablation with the 7-mm probe. With the 10-mm probe, the mean Tc and Tp were 70 degrees C and 41 degrees C, respectively. The mean distance from the edge of the lesion to the periphery was 5 mm. Impedance was 78 Ohm, and power was 4.5 watts during ablation with the 10-mm probe.

CONCLUSIONS

In an ex vivo model, bipolar RFA is capable of producing lesions with precise margins. Spread of heat is limited, evidenced histologically and by significant temperature drop off. This technology holds promise in the management of benign and malignant urologic diseases.