title: Thermal artifacts in bladder tumors following loop endoresection: electrovaporization v electrocauterization.
abstract: OBJECTIVE
  Recently, the electrovaporization (EV) technique has been used for loop endoresection of bladder tumors. Our objective was to evaluate whether bladder tumors resected by EV with a loop wire are fit for histologic diagnosis. In addition, a quantitative comparison was made with the thermal artifacts created with a standard electrocautery (EC) loop resection.
  
  
  METHODS
  In 26 patients with bladder tumors at various locations, endoresection was performed. In nonselective order, EV (N = 9; Gyrus device) or EC (N = 17; Valleylab device) was used. Histologic thermal artifacts were defined, and the diagnosis (pT classification) was determined. The linear depth of the thermal artifacts in the resected tissue was quantified with a computerized analysis system and statistically analyzed with the t-test.
  
  
  RESULTS
  One case was excluded because the tissue was not fit for morphometric measurements. In all cases, a histologic diagnosis could be made. No qualitative differences were found between the groups in the extent of histologic thermal artifacts. The mean depth of the thermal artifact zone was 0.237 mm (range 0.060-0.469 mm; SD 0.098 mm) in the EV group and 0.260 mm (range 0.080-0.410 mm; SD 0.112 mm) in the EC group. This difference is not significant (P = 0.8).
  
  
  CONCLUSIONS
  In these series, EV with a loop wire seemed to be a valid method to preserve bladder tumor specimens for histologic diagnosis. Compared with the EC method, there was no significant difference in the extent of thermal artifacts in the tissues resected.
authors.affiliation: Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. b.w.lagerveld@ac.uva.nl
authors.forename: Brunolf W
authors.initials: BW
authors.lastname: Lagerveld
authors.forename: Rob A C
authors.initials: RA
authors.lastname: Koot
authors.forename: Geert A H J
authors.initials: GA
authors.lastname: Smits
mesh_terms: D016477:Artifacts; D004564:Electrocoagulation; D004598:Electrosurgery; D006801:Humans; D001749:Urinary Bladder Neoplasms / Q000473:pathology* / Q000601:surgery*