title: Are multiple cryoprobes additive or synergistic in renal cryotherapy?
abstract: OBJECTIVE
  To investigate the relationship between multiple cryoprobes was investigated to determine whether they work in an additive or synergistic fashion in an in vivo animal model because 1.47 mm (17-gauge) cryoprobes have been introduced to the armamentarium for renal cryotherapy.
  
  
  METHODS
  Laparoscopic-guided percutaneous cryoablation was performed in both renal poles of 3 pigs using 3 IceRod cryoprobes. These 12 cryolesions were compared with 12 cryolesions using a single IceRod cryoprobe. Each cycle consisted of two 10-minute freeze cycles separated by a 5-minute thaw. The iceball volume was measured using intraoperative ultrasonography. The kidneys were harvested, and cryolesion surface area was calculated. The lesions were fixed and excised to obtain a volume measurement. Statistical analysis was used to compare the single probe results multiplied by 3 to the multiple probe group for iceball volume, cryolesion surface area, and cryolesion volume.
  
  
  RESULTS
  The iceball volume for the first freeze cycle for the single cryoprobe multiplied by 3 was 8.55 cm3 compared with 9.79 cm3 for the multiple cryoprobe group (P=.44) and 10.01 cm3 versus 16.58 cm3 for the second freeze (P=.03). The cryolesion volume for the single cryoprobe multiplied by 3 was 11.29 cm3 versus 14.75 cm3 for the multiple cyroprobe group (P=.06). The gross cryolesion surface area for the single cryoprobe multiplied by 3 was 13.14 cm2 versus 13.89 cm2 for the multiple probe group (P=.52).
  
  
  CONCLUSIONS
  The cryolesion created by 3 simultaneously activated 1.47-mm probes appears to be larger than that of an additive effect. The lesions were significantly larger as measured by ultrasonography and nearly so (P=.06) as measured by the gross cryolesion volume.
authors.affiliation: The Urology Group, Lansdowne, Virginia 20176, USA. jlyoung960@gmail.com
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Young
authors.forename: David W
authors.initials: DW
authors.lastname: McCormick
authors.forename: Surrendra B
authors.initials: SB
authors.lastname: Kolla
authors.forename: Petros G
authors.initials: PG
authors.lastname: Sountoulides
authors.forename: Oskar G
authors.initials: OG
authors.lastname: Kaufmann
authors.forename: Cervando G
authors.initials: CG
authors.lastname: Ortiz-Vanderdys
authors.forename: Victor B
authors.initials: VB
authors.lastname: Huynh
authors.forename: Adam G
authors.initials: AG
authors.lastname: Kaplan
authors.forename: Nick S
authors.initials: NS
authors.lastname: Jain
authors.forename: Donald L
authors.initials: DL
authors.lastname: Pick
authors.forename: Lorena A
authors.initials: LA
authors.lastname: Andrade
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Osann
authors.forename: Elspeth M
authors.initials: EM
authors.lastname: McDougall
authors.forename: Ralph V
authors.initials: RV
authors.lastname: Clayman
mesh_terms: D000818:Animals; D003452:Cryosurgery / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D010535:Laparoscopy / Q000379:methods; D034421:Sus scrofa; D013552:Swine; D014463:Ultrasonography