title: Completeness and efficiency of prostate tissue removal: loop resection compared with a new operative technique of transurethral electrovaporization.
abstract: OBJECTIVE
  To compare the completeness and efficiency of the removal of prostatic adenomatous tissue between transurethral resection (TURP) and a new operative technique of electrovaporization (TUEVAP) using a modified roller electrode.
  
  
  METHODS
  In a prospective double-blind study, patients with moderate to severe lower urinary tract symptoms and objective evidence of obstruction, were randomized to undergo either TURP (using a standard cutting-wire loop) or TUEVAP (performed with a new operative technique and the spiked-bar electrode). The prostate volume measured using transrectal ultrasonography (TRUS-PV) was used to assess the completeness of tissue clearance after treatment. Results were compared using group median values. For the TURP group, the TRUS-PV estimate of tissue removed was divided by the dry resected weight to derive a correction factor for any discrepancy between the values. This factor was applied to the TRUS-PV reduction in the TUEVAP group (where there was no tissue to be weighed) to estimate the actual tissue removal in this group. The efficiency of tissue removal for each treatment modality was derived by dividing the amount of tissue removed by the operative duration.
  
  
  RESULTS
  There was no difference in the reduction in TRUS-PV at 3 months (23.9 cm3 vs 21.45 cm3, P<0.9), or in the operative duration (45 min vs 52.5 min, P<0.2), between TURP and TUEVAP, respectively. The TRUS-PV of tissue removed exceeded the actual dry resected weight after TURP (15 g) by a factor of 1.59. After applying this factor to the TRUS-PV reduction for the TUEVAP group, the calculated dry weight of tissue removed for this group was 13.49 g (P<0.55); the difference in tissue removal rate by TRUS criteria was 0.48 cm3/min vs 0.37 cm3/min (P<0.15).
  
  
  CONCLUSIONS
  These data suggest an equivalent completeness of removal of adenomatous prostate tissue between TURP and TUEVAP. The efficiency of tissue removal for TUEVAP was slightly less than that of regular loop resection, but this difference was not statistically significant. These results are specific to the combination of electrode, electrosurgical unit and operative technique used in this study, and may differ if any of these variables are altered.
authors.affiliation: Department of Urology at The University of California, Los Angeles, USA.
authors.forename: A
authors.initials: A
authors.lastname: Patel
authors.forename: G J
authors.initials: GJ
authors.lastname: Fuchs
authors.forename: J
authors.initials: J
authors.lastname: Gutierrez-Acéves
authors.forename: F
authors.initials: F
authors.lastname: Andrade-Perez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004311:Double-Blind Method; D004598:Electrosurgery / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011470:Prostatic Hyperplasia / Q000473:pathology / Q000601:surgery*