Systematic Evaluation of a Recently Introduced 2-Micron Continuous Wave Thulium Laser for Vaporesection of the Prostate

Background and Purpose: A novel 2-m 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 potassiumtitanyl- 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 m for the CW thulium laser, 666.9  64.0 m for the KTP laser (P  0.05), and 287.1  27.5 m for TURP.

Conclusion: In this standardized ex-vivo investigation, the 2-m 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.