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This study evaluates tissue coagulation and ablation effects in the prostate gland of the canine model when a diode laser (805 nm-Diomed 25R-Surgimedics/ESP, The Woodlands, Texas) and an angled fiber configuration (1000 (mu) 20 degree bent-Surgimedics/ESP, The Woodlands, Texas were used at specified power densities. Comparisons of therapeutic modalities included animals treated with noncontact coagulation alone, contact ablation alone, and noncontact coagulation and contact ablation in combination. The principal objective was to validate the effectiveness of coagulating prostatic tissue in a noncontact mode at a lower power, followed immediately with contact ablation of the prostatic urethra at a higher energy level. Applying laser energy with the fiber tip in noncontact mode created a deeper zone of coagulative necrosis with an increased level of cellular destruction (lower power 15 - 20 watts delivered to four quadrants for 200 seconds/quadrant) than did higher power modalities alone. An increased luminal diameter, which prevented immediate postoperative urodynamic abnormalities (stranguria, dysuria, and severe hematuria) in this model, was produced by ablating the prostatic urethra with the fiber tip in a contact mode (higher power: 23 - 60 watts for an additional 120 - 200 seconds for the ablative process) immediately following the coagulative procedure. Additionally, semen evaluations performed before and after laser surgery (8 weeks after coagulation/ablation) were performed on one dog and found to be normal with respect to number of spermatozoa and motility.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
