Laser vaporization of the prostate in vivo: Experience with the 150-W 980-nm diode laser in living canines.

Background And Objective: Anatomic, tissue ablation and coagulation, and histopathologic outcomes of the 150-W 980-nm diode laser selective light vaporization (SLV™) of the prostate in the first survival study of living canines were analyzed.

Study Design/materials And Methods: Ten dogs underwent anterograde SLV™ with the 150-W 980-nm laser delivered by its side-firing fiber (Fusion™). Postoperatively, two dogs were euthanized at 3 hours as planned, six at 2-7 days due to complications, and two, without complications, at 8 weeks as planned. Laser energy and time were recorded. Prostates were sectioned, measured, and histologically analyzed after hematoxylin and eosin (H&E), triphenyltetrazolium chloride (TTC), or Gomori trichrome (GT) staining.

Results: SLV™ acutely and hemostatically created a 0.6 ± 0.3 cm(3) cavity in the 3-hour group accompanied by H&E- and TTC-identified coagulation necrosis of up to 9.5 mm (6.1 ± 1.2 mm) that led to prostatic slough-induced obstruction and perforation in six of eight (75%) surviving animals, necessitating unplanned euthanasia within 2-7 days. H&E- and GT-stained prostates at 8 weeks postoperatively showed large (9.6 ± 1.4 cm(3)) re-epithelialized prostatic cavities with persistent diffuse interstitial Prostatitis and collagenous fibrosis.

Conclusion: SLV™ with the 150-W 980-nm diode laser in living canines produced small cavities acutely, and was accompanied by deeply necrotic prostatic slough-induced obstruction and perforation in a majority of animals. A minority survived SLV and had favorable anatomic outcomes whereas histology revealed persisting inflammation. Further in vivo studies and a cautious clinical approach are recommended to finally evaluate the potential of SLV™ with the 150-W 980-nm diode laser.