Nd: YAG surgical laser effects in canine prostate tissue: ablation effect and damage distribution

Objective: To evaluate therapy effects and capability to preserve adjacent tissues of bilateral focal prostate ablation using Nd: YAG laser a canine model. Methods: 24 male Beagle dogs aged 3.9-7.4 years and weighting 9.4-12.1 kg were used in this study. The dogs underwent single focal Nd: YAG ablation. Applied the reasonable prostatic ablation parameters screened in the study and set different intervals test of fiber lasers for ablation of prostate-urethral tissue, then observed whether thermal damage occurred and therapy effect. Results: the single focal ablation zone area was 0.7 cm2 but when Distance of double needle laser was 3 mm, the ablation area was 1.25 cm2. With the distance increased, the ablation area significantly extended. The ablation area was 1.53, 1.62, 1.65 cm2 when focal distance was 6, 9, 12 mm, respectively. Although the area extended to 1.65 cm2 when the distance enlarged from 9 cm to 12 cm, the extension range was negligible. Hence, the rational focal distance was 9 mm. In the two-dimensional ultrasonographic examinations, the coagulation necrosis of ablation area showed the approximate oval area with no contrast agent and strong comparison with the surrounding prostate tissue in which enhancement effect of the contract agent exist, which made their boundary more distinct. Conclusion: Nd: YAG prostate ablation is shown to be a safe non-thermal ablative technique capable of preserving the adjacent structures and physiological functions. Further studies are needed to fully explore the advantages of Nd: YAG compared with other ablative techniques.