title: Predictive preoperative factors for renal insufficiency in patients followed for more than 5 years after radical nephrectomy.
abstract: OBJECTIVE
  We assessed the predictive factors for renal insufficiency in patients followed for more than 5 years after radical nephrectomy.
  
  
  METHODS
  Age, gender, history of diabetes, history of hypertension, body mass index, preoperative estimated glomerular filtration rate (eGFR), serum uric acid, urine albumin, normal renal parenchymal volume, tumor size, and ratio of normal parenchymal volume of the removed kidney to that of the remaining kidney were evaluated retrospectively in 89 patients who underwent radical nephrectomy from January 2001 to December 2005. Patients were included whose renal parenchymal volume was measurable by use of perioperative imaging (computed tomography or magnetic resonance imaging), whose preoperative eGFR was greater than 60 mL/min/1.73 m(2), and who were followed for more than 5 years. To measure renal parenchymal volume from imaging, we integrated the extent of the normal renal parenchyma from axial slides of images.
  
  
  RESULTS
  In univariate and multivariate binary regression analysis, the parenchymal volume of the remnant kidney (p=0.001), a history of diabetes (p=0.035), and preoperative eGFR (p=0.011) were independent factors for renal insufficiency. By use of a receiver operating characteristic curve, a volume of 170 mL was determined to be an appropriate cutoff value, with sensitivity of 58.7% and specificity of 74.4% for the parenchymal volume of the remnant kidney for predicting eGFR less than 60 mL/min/1.73 m(2) (area under the curve, 0.678). The parenchymal volume of the remnant kidney was also an independent factor for the downgrading of the chronic kidney disease category in the multivariate linear regression analysis (p=0.021).
  
  
  CONCLUSIONS
  Preoperative eGFR, a history of diabetes, and the radiologic volume of the remaining kidney parenchyma could be useful factors for predicting postoperative renal function. Patients with parenchymal volumes of less than 170 mL have a higher risk of postoperative renal insufficiency, which should be considered carefully when choosing a treatment modality.
authors.affiliation: Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joong Seo
authors.initials: JS
authors.lastname: Ahn
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hwang Gyun
authors.initials: HG
authors.lastname: Jeon
authors.forename: Byong Chang
authors.initials: BC
authors.lastname: Jeong
authors.forename: Seong Il
authors.initials: SI
authors.lastname: Seo
authors.forename: Hyun Moo
authors.initials: HM
authors.lastname: Lee
authors.forename: Han Yong
authors.initials: HY
authors.lastname: Choi
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Jeon
keywords: Kidney; Nephrectomy; Organ size; Renal insufficiency