title: Histomorphological changes after neodymium: YAG laser-coagulation of the human prostate with the Side Focus fiber. Effect of power setting and time.
abstract: The objective of our study was to determine optimal treatment parameters and appropriate methods of examination for neodymium:yttrium-aluminum-garnet (Nd:YAG) high-power laser coagulation of the human prostate in relation to power setting and time. Transurethral free-beam laser coagulation was performed with the Side Focus side-firing laser fiber in ten patients prior to planned radical surgery, of whom six underwent transperitoneal laparoscopic lymphadenectomy and laser coagulation 4-9 days prior to open surgery. Depth and volume of coagulated prostatic tissue were measured at power setting/time combinations of 40 W/90 s and 60 W/60 s, respectively, while holding total energy delivery constant. Microscopic examination in the early phase showed that epithelial cells had become loose from the basal-cell membrane. By 4-9 days there was evidence of conspicuous squamous epithelial metaplasia with a high proliferation rate as a sign of re-epithelialization. Using the Side Focus side-firing laser fiber, both treatment modalities showed comparable volume coagulation. In contrast there was a significant difference between those prostates removed at 4-9 days and those removed at 60-210 min after laser coagulation. We conclude that laser-induced changes in the human prostate are conclusively discernible only after 4 days.
authors.affiliation: Department of Urology, University Hospital Zurich, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Sulser
authors.forename: W
authors.initials: W
authors.lastname: Jochum
authors.forename: P U
authors.initials: PU
authors.lastname: Heitz
authors.forename: D
authors.initials: D
authors.lastname: Hauri
mesh_terms: D000368:Aged; D006801:Humans; D017075:Laser Coagulation / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009354:Neodymium; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D013997:Time Factors
chemical_list: D009354:Neodymium