title: Comparison of cold and warm ischemia during partial nephrectomy in 660 solitary kidneys reveals predominant role of nonmodifiable factors in determining ultimate renal function.
abstract: OBJECTIVE
  Factors that determine renal function after partial nephrectomy are not well-defined, including the impact of cold vs warm ischemia, and the relative importance of modifiable and nonmodifiable factors. We studied these determinants in a large cohort of patients with a solitary functioning kidney undergoing partial nephrectomy.
  
  
  METHODS
  From 1980 to 2009, 660 partial nephrectomies were performed at 4 centers for tumor in a solitary functioning kidney under cold (300) or warm (360) ischemia. Data were collected in institutional review board approved registries and followup averaged 4.5 years. Preoperative and postoperative glomerular filtration rates were estimated via the Chronic Kidney Disease-Epidemiology Study equation.
  
  
  RESULTS
  At 3 months after partial nephrectomy median glomerular filtration rate decreased by equivalent amounts with cold or warm ischemia (21% vs 22%, respectively, p = 0.7), although median cold ischemic times were much longer (45 vs 22 minutes respectively, p <0.001). On multivariable analyses increasing age, larger tumor size, lower preoperative glomerular filtration rate and longer ischemia time were associated with decreased postoperative glomerular filtration rate (p <0.05). When percentage of parenchyma spared was incorporated into the analysis, this factor and preoperative glomerular filtration rate proved to be the primary determinants of ultimate renal function, and duration of ischemia lost statistical significance.
  
  
  CONCLUSIONS
  This nonrandomized, comparative study suggests that within the relatively strict parameters of conventional practice, ie predominantly short ischemic intervals and liberal use of hypothermia, ischemia time was not an independent predictor of ultimate renal function after partial nephrectomy. Long-term renal function after partial nephrectomy is determined primarily by the quantity and quality of renal parenchyma preserved, although type and duration of ischemia remain the most important modifiable factors, and warrant further study.
authors.affiliation: Glickman Urological & Kidney Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Lane
authors.forename: Paul
authors.initials: P
authors.lastname: Russo
authors.forename: Robert G
authors.initials: RG
authors.lastname: Uzzo
authors.forename: Adrian V
authors.initials: AV
authors.lastname: Hernandez
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boorjian
authors.forename: R Houston
authors.initials: RH
authors.lastname: Thompson
authors.forename: Amr F
authors.initials: AF
authors.lastname: Fergany
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Love
authors.forename: Steven C
authors.initials: SC
authors.lastname: Campbell
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D015331:Cohort Studies; D050377:Cold Ischemia / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007677:Kidney Function Tests; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009392:Nephrectomy / Q000009:adverse effects / Q000379:methods*; D011183:Postoperative Complications / Q000503:physiopathology; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D052096:Warm Ischemia / Q000009:adverse effects / Q000379:methods*