title: Prolonged cold ischemia time for laparoscopic partial nephrectomy with a new cooling material: Freka-Gelice--a comparison of four cooling methods.
abstract: OBJECTIVE
  It is well known that hypothermia protects renal tissue from ischemic damage. So far, no standardized cooling method for laparoscopic surgery has been established. The traditionally used cooling method during open partial nephrectomy (OPN) is crushed ice applied around the kidney; for laparoscopic use, transarterial and transureteral perfusion cooling are described. We compared these three cooling methods with Freka-Gelice (FG), a new gel-like cooling material, and present our initial preliminary results in an ex-vivo porcine model.
  
  
  METHODS
  To prove cooling effectiveness, FG was compared with superficial crushed ice (NaCl-ice), with transureteral perfusion (TUP), and with transarterial perfusion (TAP) cooling in ex-vivo porcine kidneys. The temperature decrease over 120 minutes and practical application were evaluated.
  
  
  RESULTS
  No significant difference was found for the mean value distribution at different time points for NaCl-ice and FG (P = 0.18). TUP and TAP showed insufficient temperature decrease. Mean temperatures for NaCl-ice and FG were 4.75 degrees C and 7.02 degrees C at 30 minutes, 0.72 degrees C and 2.47 degrees C at 60 minutes, and -0.19 degrees C and 2.35 degrees C at 120 minutes, respectively. FG was easy to use because of its gel-like consistence.
  
  
  CONCLUSIONS
  TUP and TAP did not provide a fast and sufficient temperature decrease for renal hypothermia in this ex-vivo model. FG shows sufficient cooling qualities comparable with conventionally used NaCl-ice. Because of its gel-like consistence, FG can be used for laparoscopic partial nephrectomy, because insertion through a trocar is possible.
authors.affiliation: Department of Urology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. gita.schoeppler@umm.de
authors.forename: Gita M
authors.initials: GM
authors.lastname: Schoeppler
authors.forename: Elena
authors.initials: E
authors.lastname: Klippstein
authors.forename: Johannes
authors.initials: J
authors.lastname: Hell
authors.forename: Axel
authors.initials: A
authors.lastname: Häcker
authors.forename: Lutz
authors.initials: L
authors.lastname: Trojan
authors.forename: Peter
authors.initials: P
authors.lastname: Alken
authors.forename: Maurice-Stephan
authors.initials: MS
authors.lastname: Michel
mesh_terms: D000818:Animals; D050377:Cold Ischemia / Q000379:methods*; D005780:Gelatin; D010535:Laparoscopy; D015636:Magnesium Chloride; D009392:Nephrectomy / Q000379:methods*; D011189:Potassium Chloride; D012965:Sodium Chloride; D019354:Sodium Lactate; D013552:Swine; D013997:Time Factors
chemical_list: D015636:Magnesium Chloride; D012965:Sodium Chloride; D011189:Potassium Chloride; D005780:Gelatin; D019354:Sodium Lactate