title: Parenchymal volume preservation and ischemia during partial nephrectomy: functional and volumetric analysis.
abstract: OBJECTIVE
  To determine the relative effect of type and duration of ischemia and parenchymal volume preservation on renal function after partial nephrectomy (PN).
  
  
  METHODS
  Ninety-two patients with localized renal tumors (2007-2012) managed with PN at our center with necessary studies for analysis were included. This comprised 37 patients with a solitary kidney and 55 with a contralateral kidney. Thirty-five patients were managed with hypothermia and 57 with limited warm ischemia. Volumetric computed tomography was used to measure the volume of functional parenchyma before and after PN in the operated and contralateral kidneys. Glomerular filtration rate (GFR) was determined by the modification of diet in renal disease 2 equation, along with renal scan data for patients with a contralateral kidney. Regression analysis assessed the relationships between %GFR preserved in the operated kidney and potential predictive factors. All postoperative analyses were performed 4-12 months after surgery.
  
  
  RESULTS
  Median age was 61 years, median tumor size 3.5 cm, and median RENAL nephrometry score 8. Median cold ischemia time was 28 minutes and median warm ischemia time 21 minutes. Median %GFR preserved in the operated kidney was 79%. Median %parenchymal volume saved was 83%. Function in the contralateral kidney only increased marginally (median increase 6%). On regression analysis, %GFR preserved associated most strongly with %parenchymal volume saved (P <.0001), but also with lower RENAL scores (P = .0457) and the use of hypothermia (P = .0209). In contrast, ischemia time did not correlate with %GFR preserved (P = .5051).
  
  
  CONCLUSIONS
  Ultimate function after PN primarily correlated with parenchymal volume preservation, whereas ischemia played a secondary role. Thus, maximal parenchymal preservation with a precise PN should be a priority during PN.
authors.affiliation: Glickman Urological & Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Mir
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Campbell
authors.forename: Nidhi
authors.initials: N
authors.lastname: Sharma
authors.forename: Erick M
authors.initials: EM
authors.lastname: Remer
authors.forename: Matt N
authors.initials: MN
authors.lastname: Simmons
authors.forename: Jianbo
authors.initials: J
authors.lastname: Li
authors.forename: Sevag
authors.initials: S
authors.lastname: Demirjian
authors.forename: Jihad
authors.initials: J
authors.lastname: Kaouk
authors.forename: Steven C
authors.initials: SC
authors.lastname: Campbell
mesh_terms: D000368:Aged; D050377:Cold Ischemia; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology*; D007680:Kidney Neoplasms / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009392:Nephrectomy / Q000379:methods*; D009929:Organ Size; D020127:Recovery of Function; D012044:Regression Analysis; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D052096:Warm Ischemia