NEW DEVICE FOR VISUAL NEODYMIUM-YAG LASER PROSTATE ABLATION - ACUTE AND CHRONIC CANINE EVALUATION

Citation
Ge. Kopchok et al., NEW DEVICE FOR VISUAL NEODYMIUM-YAG LASER PROSTATE ABLATION - ACUTE AND CHRONIC CANINE EVALUATION, Lasers in surgery and medicine, 15(3), 1994, pp. 254-262
Citations number
16
Categorie Soggetti
Medical Laboratory Technology",Surgery
ISSN journal
01968092
Volume
15
Issue
3
Year of publication
1994
Pages
254 - 262
Database
ISI
SICI code
0196-8092(1994)15:3<254:NDFVNL>2.0.ZU;2-F
Abstract
This canine study (n = 6) evaluated the acute and chronic effects of N d:YAC; laser prostatectomy using a Prolase II fiber. The Prolase II de vice consists of a 1,000 mu m quartz fiber which directs a cone of Nd: YAG; laser energy, at 45 degrees to the aids of the fiber, into the pr ostatic urethra under direct visual guidance [visual laser ablation of prostate, (VLAP)]. Under visual guidance and saline irrigation, 60 se conds of 60 watts of laser power was delivered at 3, 6, 9, and 12 o'cl ock positions (14,400 J). One canine was instrumented but received no laser energy (control). One prostate was harvested acutely. The remain ing four laser-treated dogs were evaluated at 6 to 16 weeks. The histo pathology of acute laser effects shows areas of necrosis with loss of glandular structures and stromal edema. Surrounding this area was a zo ne of degenerative glandular structures extending up to 12.6 mm into t he prostate. Two of the four dogs developed urinary retention at 6.5 a nd 9 weeks. On examination, both were found to have fibrotic stricture s at the distal prostatic urethra with markedly dilated proximal prost atic urethral lumens (1.98 and 2.8 cm). Two other dogs showed no signs of urinary retention at sacrifice. Histopathology, both the 6 and 16 week laser-treated animals without urinary retention demonstrated dila ted prostatic urethras with maximum cross-sectional diameters of 1.52 and 1.50 cm, respectively. However, the 16 week dog demonstrated mild distal urethral narrowing by urethrogram. The control dog demonstrated normal histology of the prostate at 16 weeks. This study demonstrates the safety and initial results of a delivery device for transurethral laser prostate ablation in a canine model. Further studies are needed to evaluate the cause of the fibrotic urethral strictures in this mod el and determine its clinical relevance. (C) 1994 Wiley-Liss, Inc.