title: Impact of warm versus cold ischemia on renal function following partial nephrectomy.
abstract: BACKGROUND
  We evaluated renal function following partial nephrectomy with cold ischemia (CI) versus warm ischemia (WI).
  
  
  METHODS
  Data were collected from 1,396 patients at six institutions who underwent partial nephrectomy for a renal mass with normal contralateral kidney to evaluate percent change in glomerular filtration rate (GFR) at 3-18 months. A multivariate linear regression model tested the association of percent change GFR with clinical, operative, and pathologic factors.
  
  
  RESULTS
  A total of 874 patients (63 %) underwent PN with CI and 522 (37 %) with WI. All patients undergoing laparoscopic and robotic-assisted partial nephrectomy (n = 443) had WI, whereas 92 % of open partial nephrectomy patients (n = 953) had CI. The CI group had a lower mean baseline GFR (72 vs. 80 ml/min/1.73 m(2)), longer median ischemia time (33 vs. 29 min), and larger mean tumor size (3.2 vs. 2.9 cm) with more advanced pathologic stage (T1b-T3: 25 vs. 16 %) (all p values <0.001). Patients with CI and WI demonstrated 12.3 and 10.1 % reductions in renal function from baseline, respectively (p = 0.067). Increasing age, female gender, and increasing tumor size were associated with reduction in renal function (all p values <0.001). Neither renal hypothermia nor operative technique independently predicted reduced renal function. Sensitivity analyses limited to ischemia time >30 min, baseline estimated glomerular filtration rate <60 ml/min/1.73 m(2), or tumors >4 cm did not significantly alter the findings.
  
  
  CONCLUSIONS
  Increasing age, female gender, and larger tumor size independently predict a decrease in renal function following partial nephrectomy with a normal contralateral kidney. Within the limitations of a non-randomized comparison, including lack of parenchymal preservation percentage, neither surgical approach (open or laparoscopic) nor presence of hypothermia appears to be associated with long-term renal function.
authors.affiliation: Section of Urology, University of Chicago, 5841 South Maryland Avenue, Mail Code 6038, Chicago, IL, 60614, USA, seggener@surgery.bsd.uchicago.edu.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Eggener
authors.forename: Melanie A
authors.initials: MA
authors.lastname: Clark
authors.forename: Sergey
authors.initials: S
authors.lastname: Shikanov
authors.forename: Benjamin
authors.initials: B
authors.lastname: Smith
authors.forename: Matthew
authors.initials: M
authors.lastname: Kaag
authors.forename: Paul
authors.initials: P
authors.lastname: Russo
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Wheat
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Wolf
authors.forename: Surena F
authors.initials: SF
authors.lastname: Matin
authors.forename: William C
authors.initials: WC
authors.lastname: Huang
authors.forename: Miriam
authors.initials: M
authors.lastname: Harel
authors.forename: Joseph
authors.initials: J
authors.lastname: Cambio
authors.forename: Arieh L
authors.initials: AL
authors.lastname: Shalhav
authors.forename: Jay D
authors.initials: JD
authors.lastname: Raman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D050377:Cold Ischemia / Q000379:methods*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D007680:Kidney Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D012737:Sex Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D052096:Warm Ischemia / Q000379:methods*