High-power diode laser at 980 nm for the treatment of benign prostatic hyperplasia: ex vivo investigations on porcine kidneys and human cadaver prostates.

Diode laser systems at 980 nm have been introduced for the treatment of lower-urinary-tract-symptoms (LUTS) suggestive of benign prostatic enlargement (BPE). However, the coagulation and vaporization properties are unknown. We therefore aimed to evaluate these properties in ex vivo models in comparison with the kalium-titanyl-phosphate-(KTP) laser. The diode laser treatment was applied to isolated, blood-perfused porcine kidneys and fresh human cadaver prostates (HCPs) at different generator settings. We performed histological examination to compare the depth of coagulation and vaporization. The diode laser showed larger ablation and coagulation characteristics than the KTP laser did. Ablation of the diode laser was found to be 1.79-times (120 W in porcine kidney, P < 0.0001) and 3.0-5 times (200 W in HCP, P < 0.0005) larger. The diode laser created a nine-times (120 W in porcine kidney, P < 0.0001) and seven-times (200 W in HCP, P < 0.0001) deeper necrosis zone. The diode laser vaporization was highly effective ex vivo. Owing to the laser's deep coagulation zones, in vivo animal experiments are mandatory before the diode laser (980 nm) is applied in a clinical setting, so that damage to underlying structures is prevented.