Laser therapy in dogs and humans--is there a difference?

Abstract

To compare quantitatively the reduction of volume of benign prostatic hyperplasia (BPH) achieved by laser therapy in dogs and men. Twelve mongrels, with a mean prostatic volume of 33.4 mL, underwent transurethral laser treatment using an Nd:YAG laser with an Ultraline fibre at 60 W power setting. The reduction in prostatic volume was assessed quantitatively 3 months after treatment using stereological methods. Forty patients (mean age 70.2 years, range 51-84) with symptomatic BPH (pre-operative mean prostate volume 46.3 mL) were treated under similar operative conditions with the same laser, power and fibre system. Their urinary performance was assessed before and 6 months after treatment using urinary flow rates, residual volume and a symptom score, and their prostatic volume and necrosis assessed using transrectal ultrasonography. After laser treatment, the mean reduction in the dog prostate volume was 50% and in the patients was only 21%. The different impact was probably caused by anatomical differences between the human and dog prostate; the human prostate consists mainly of stromal tissue and the canine prostate of glandular epithelium. The canine model gives only an approximate guide to the extent of tissue destruction that laser treatment can achieve in men with BPH. Furthermore, tissue differences between men may also affect the response to laser treatment.