Systematic evaluation of a recently introduced 2-microm continuous-wave thulium laser for vaporesection of the prostate.

BACKGROUND AND PURPOSE: A novel 2-microm continuous wave (CW) thulium laser device for interventional treatment of benign prostatic hyperplasia was recently introduced into clinical practice and is postulated to have several advantages over more established laser devices. A systematic ex-vivo evaluation of the thulium laser was undertaken to compare the results to transurethral resection of the prostate (TURP) and the potassium-titanyl-phosphate (KTP) laser as reference standard methods. MATERIALS AND METHODS: The RevoLix CW thulium laser system was evaluated in the well-established model of the isolated blood-perfused porcine kidney to determine its tissue ablation capacity and hemostatic properties at different power settings. Histologic examination of the ablated tissue followed. The results were compared to the reference standards, TURP and 80-W KTP laser. RESULTS: At a power setting of 70 W, the CW thulium laser displays a higher tissue ablation rate, reaching 6.56+/-0.69 g after 10 minutes, compared to the 80 W KTP laser (3.99+/-0.48 g; P<0.05). Only 30 seconds were needed to resect tissue with the same surface area using TURP, resulting in 8.28+/-0.38 g of tissue removal. With a bleeding rate of 0.16+/-0.07 g/min, the CW thulium laser offers hemostatic properties equal to those of the KTP laser (0.21+/-0.07 g/min), and a significantly reduced bleeding rate compared to TURP (20.14+/-2.03 g/min; P<0.05). The corresponding depths of the coagulation zones were 264.7+/-41.3 microm for the CW thulium laser, 666.9+/-64.0 microm for the KTP laser (P<0.05), and 287.1+/-27.5 microm for TURP. CONCLUSION: In this standardized ex-vivo investigation, the 2-microm CW thulium laser offered a higher tissue ablation capacity and similar hemostatic properties as those of the KTP laser, and in comparison to TURP both tissue ablation and the bleeding rate were significantly reduced.

980-nm Diode laser: a novel laser technology for vaporization of the prostate.

OBJECTIVE: The wavelength 980 nm of a recently introduced diode laser system for treatment of benign prostatic enlargement offers a high simultaneous absorption in water and haemoglobin, and is postulated to combine high tissue ablative properties with a good haemostasis. METHODS: The Ceralas HPD150 diode laser system was evaluated in the well-established ex vivo model of the isolated blood-perfused porcine kidney to evaluate tissue ablation capacity and haemostatic properties at different generator settings. A histological examination of the ablated renal tissue followed. The results were compared with the reference standards transurethral resection of the prostate (TURP) and potassium-titanyl-phosphate (KTP) laser. RESULTS: The diode laser displays a higher tissue ablation capacity, reaching 7.24+/-1.48 g after 10 min, compared with the KTP laser (3.99+/-0.48 g; p<0.05), whereas only 30s are needed to resect the tissue in the same surface area using TURP, resulting in 8.28+/-0.38 g of tissue removal. With a bleeding rate of 0.14+/-0.07 g/min, the diode laser offers haemostatic properties equivalent to the KTP laser (0.21+/-0.07 g/min) and a significantly reduced bleeding compared with TURP (20.14+/-2.03 g/min; p<0.05). The corresponding depths of the coagulation zones are 290.1+/-46.9 microm for the diode laser, 666.9+/-64.0 microm for the KTP laser (p<0.05), and 287.1+/-27.5 microm for TURP. CONCLUSIONS: In the standardised ex vivo investigation, the 980-nm diode laser offers a higher tissue ablation capacity and similar haemostasis compared with the KTP laser. In comparison with TURP, both tissue ablation and bleeding are significantly reduced. The promising ex vivo results warrant further clinical investigation.