title: Cold renal ischemia: comparison of efficacy between two techniques of cooling, in a swine model.
abstract: OBJECTIVE
  In a swine model of renal ischemia, we compared the effectiveness of the transurethral retrograde cold saline perfusion technique to the traditional method of renal cooling with ice slush, in achieving adequate parenchymal temperatures for functional preservation of the organ. Physiological and histological effects were also assessed.
  
  
  METHODS
  Twenty-four domestic male pigs were sampled into four groups to be submitted to a 60-minute ischemia of the left kidney without cooling, with either one of the two cooling techniques (cold saline retrograde perfusion or ice slush), or sham surgery. All of them had also a concomitant right nephrectomy. Renal cortical and medullary temperatures were recorded throughout the experiment. Urinary output was measured, and serum renal function tests were carried on, pre- and postoperatively. After 5 days, the animals were euthanized and their kidneys were submitted to histological analysis.
  
  
  RESULTS
  Mean renal temperature fell in both groups submitted to kidney cooling. With ice slush, a faster drop was observed and a lower minimum temperature was achieved (5.0 degrees C in the cortex and 6.3 degrees C in the medulla, vs. 25.4 degrees C and 24.9 degrees C with retrograde cooling). In the other groups, temperature was unchanged. Urinary output and serum creatinine worsened after the experiment, but without significant differences among groups. The histological analysis showed no differences among the four groups, for the studied ischemia time.
  
  
  CONCLUSIONS
  Ice slush and retrograde perfusion of cold saline are both effective for cooling the kidney during ischemia. Ice slush is faster in doing so, and it allows much lower temperatures to be achieved in the renal parenchyma. With ischemia time of 60 minutes, no significant differences on the occurrence of functional and histological alterations were detected, even for the group without a cooling procedure.
authors.affiliation: Department of Urology, School of Medicine, São Paulo State University (UNESP), Botucatu, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Guerra
authors.forename: Eduardo Piotto
authors.initials: EP
authors.lastname: Leonardi
authors.forename: Rodrigo Arthur
authors.initials: RA
authors.lastname: Otsuka
authors.forename: Juliany
authors.initials: J
authors.lastname: Quitzan
authors.forename: Paulo Roberto
authors.initials: PR
authors.lastname: Kawano
authors.forename: Hamilto Akihissa
authors.initials: HA
authors.lastname: Yamamoto
authors.forename: João Luiz
authors.initials: JL
authors.lastname: Amaro
authors.forename: Oscar Eduardo H
authors.initials: OE
authors.lastname: Fugita
mesh_terms: D000818:Animals; D001831:Body Temperature; D050377:Cold Ischemia / Q000379:methods*; D007668:Kidney / Q000098:blood supply* / Q000601:surgery*; D007672:Kidney Cortex / Q000098:blood supply / Q000601:surgery; D007679:Kidney Medulla / Q000098:blood supply / Q000601:surgery; D008297:Male; D023421:Models, Animal; D013552:Swine / Q000601:surgery*; D016896:Treatment Outcome