In vitro comparison of transurethral vaporization of the prostate (TUVP), resection of the prostate (TURP), and vaporization-resection of the prostate (TUVRP)

Abstract.

Problem. Transurethral vaporization of the prostate (TUVP) and vaporization-resection of the prostate (TUVRP) ("vapor cut, band electrode") seem to be alternatives to conventional resection of the prostate (TURP). For TUVP and TUVRP, little in vitro data has yet been published. The aim of this study was to determine settings for optimal performance with TUVP and TUVRP and to investigate electrosurgical parameters relevant to safety. Methods. Standardized experiments were performed on porcine muscle. Mass loss and coagulation zones were measured optically. Additionally, electrical parameters were recorded. Results. The maximum tissue ablation rates were 3.8 cm³ per min and 6.1 cm³ per min for TUVP and TUVRP, respectively, compared to 6.5 cm³ per min for TURP. The maximum coagulation depths reached 2.1 mm (TUVP), 1.4 mm (TUVRP), and 0.9 mm (TURP). Optimal in vitro settings for TUVP/TUVRP/TURP were as follows: generator power of 250/120/90 W, drag speed of 5/15/20 mm/s, and pressure of 0.40/0.15/0.05 N. Different power generators and electrodes showed considerably varying performance. The energy to remove 1 g of tissue averaged 7.500 J (TUVP), 620 J (TUVRP), and 400 J (TURP). Conclusions. These results allow quantification of the influence of different variables on TUVP, TUVRP, and TURP in vitro. The TUVP proves to be an effective ablation alternative. Nevertheless, a 15 to 20 times higher energy demand has to be considered. TUVRP combines excellent ablation features with greater coagulation volumes, indicating better hemostasis.