title: Transurethral bladder cryoablation in the porcine model.
abstract: OBJECTIVE
  To examine the feasibility of transurethral, focal, full-thickness bladder wall cryoablation in the porcine model using a novel 38-cm cryoablation probe.
  
  
  METHODS
  A total of 18 pigs were divided into three groups. Groups 1 (n = 6) and 2 (n = 6) underwent transurethral bladder wall cryoablation in a saline environment with two freeze-thaw cycles. The pigs in groups 1 and 2 were killed after 1 and 3 weeks, respectively. The pigs in group 3 (n = 6) underwent transurethral cryoablation after the bladder had been insufflated with carbon dioxide gas. The pigs in group 3 were killed after 1 week. In all groups, laparoscopic access was obtained to protect the abdominal contents from the transmural cryoablation process. Bladder integrity was evaluated with cystography and laparoscopic visualization, and each cryolesion was excised en bloc for extensive histopathologic evaluation.
  
  
  RESULTS
  All 18 pigs successfully underwent bladder wall cryoablation. For all groups, the preoperative, postoperative, and sacrifice cystograms were without evidence of extravasation. No urinomas, hematomas, or adhesions were present in groups 1 and 2. Minimal adhesions were identified in 3 (50%) of 6 pigs in group 3. For groups 1, and 2, the mean length and width of the area of complete necrosis on histopathologic evaluation was 6.5 and 3.0 mm and 2.3 and 1.3 mm, respectively. For group 3, the mean diameter of the cryolesion was 8.2 mm. Full-thickness necrosis was confirmed in all groups.
  
  
  CONCLUSIONS
  The results of our study have shown that, in this model, complete full-thickness transurethral bladder wall cryoablation, with maintenance of bladder wall integrity, is feasible.
authors.affiliation: Department of Urology, Columbia University Medical Center, New York, New York 10032, USA.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Hruby
authors.forename: Franzo
authors.initials: F
authors.lastname: Marruffo
authors.forename: Jorge
authors.initials: J
authors.lastname: Ortiz
authors.forename: Evren
authors.initials: E
authors.lastname: Durak
authors.forename: Andrew
authors.initials: A
authors.lastname: Edelstein
authors.forename: Gabriel
authors.initials: G
authors.lastname: Levi
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D000818:Animals; D003452:Cryosurgery / Q000379:methods*; D015653:Cystectomy / Q000379:methods*; D005240:Feasibility Studies; D013552:Swine; D014521:Urethra