title: Durability of probes for interstitial laser coagulation: impact of power setting and probe design.
abstract: OBJECTIVE
  Interstitial laser coagulation (ILC) is a well-established treatment option for patients suffering from benign prostatic hyperplasia (BPH). The vulnerability of the current fibers adds to the high cost of the procedure. The objective was to study the impact of different time-power modes and novel probe designs on tissue effects and fiber durability.
  
  
  METHODS
  Standardized interstitial laser (Nd:YAG) applications utilizing different fiber types and power settings were performed in vitro on fresh bovine liver in a fluid medium. The resulting effects on tissue coagulation were evaluated. Additionally, the durability of contemporary probes as well as novel designs was examined.
  
  
  RESULTS
  High-intensity application protocols of 1750 J within 60 seconds were significantly (p < 0.001) more effective in coagulating tissue (4.22 cm3) than the 90 seconds (3.68 cm3) and 120 seconds (3.06 cm3) time-power modes but significantly (p < 0.001) decreased the durability of fibers. Prototype probes significantly improved durability (p < 0.001), whereas efficacy remained unchanged (p > 0.5).
  
  
  CONCLUSIONS
  Using a laboratory model, we could demonstrate that high-intensity time-power settings are more effective in creating tissue coagulation in ILC. The resulting deterioration of the probes can be reduced by applying new fiber designs.
authors.affiliation: Department of Urology, Ludwig-Maximilians-University, Munich, Germany. oreich@uro.med.uni-muenchen.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Reich
authors.forename: Maurice S
authors.initials: MS
authors.lastname: Michel
authors.forename: Peter
authors.initials: P
authors.lastname: Schneede
authors.forename: Bernhard
authors.initials: B
authors.lastname: Liedl
authors.forename: Alfons
authors.initials: A
authors.lastname: Hofstetter
mesh_terms: D000818:Animals; D002417:Cattle; D017075:Laser Coagulation / Q000295:instrumentation* / Q000379:methods*; D023421:Models, Animal