title: Clinical implications for graft function of a new equation model for the ratio of living donor kidney volume to recipient body surface area.
abstract: OBJECTIVE
  We propose an equation that predicts graft function after kidney transplantation by using donated kidney volume and recipient body surface area (BSA).
  
  
  METHODS
  Included were 261 cases of living kidney transplantation between 2007 and 2009. Preoperative computed tomography scans were performed and the donated kidney volume was measured by use of a three-dimensional reconstruction program (Ripidia). The estimated glomerular filtration rate (eGFR) was calculated by using the modification of diet in renal disease formula. Donated kidney volume, preoperative renal function, and demographic factors of both donors and recipients were evaluated as predictors.
  
  
  RESULTS
  The mean ages of the donors and recipients were 40.8 and 41.6 years, respectively. The mean donated kidney volume and donated kidney volume/recipient BSA ratio were 153.4 mL and 96.9 mL/m(2), respectively. Mean preoperative and postoperative 12-month eGFR of recipients were 7.1 and 59.7 mL/min, respectively, and the mean preoperative eGFR of donors was 92.2 mL/min. Donated kidney volume/recipient BSA ratio, donor age, and recipient gender were the significant predictors of eGFR level (p<0.001) and eGFR<45 mL/min at postoperative 12 months (p=0.005, p<0.001, and p=0.006). From the multiple linear regression equation and predicted probability from logistic regression, we could calculate the equation for the ratio of living donor kidney volume to recipient BSA on graft function.
  
  
  CONCLUSIONS
  Graft kidney volume/recipient BSA ratio, donor age, and recipient gender were predictors of graft function 12 months after kidney transplantation. Although we are concerned only with the preoperative, this equation model could help physicians to counsel patients concerning their postoperative prognosis and to avoid insufficient volume donations.
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University Health System, Seoul, Korea.
authors.forename: Chang Ki
authors.initials: CK
authors.lastname: Lee
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University Health System, Seoul, Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Yoon
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University Health System, Seoul, Korea.
authors.forename: Kyung Hwa
authors.initials: KH
authors.lastname: Choi
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University Health System, Seoul, Korea.
authors.forename: Seung Choul
authors.initials: SC
authors.lastname: Yang
authors.affiliation: Department of Urology, Cheil General Hospital & Women's Healthcare Center, Kwandong University College of Medicine, Seoul, Korea.
authors.forename: Joong Shik
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Surgery, The Research Institute for Transplantation, Yonsei University Health System, Seoul, Korea.
authors.forename: Dong Jin
authors.initials: DJ
authors.lastname: Joo
authors.affiliation: Department of Surgery, The Research Institute for Transplantation, Yonsei University Health System, Seoul, Korea.
authors.forename: Kyu Ha
authors.initials: KH
authors.lastname: Huh
authors.affiliation: Department of Surgery, The Research Institute for Transplantation, Yonsei University Health System, Seoul, Korea.
authors.forename: Yu Seun
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University Health System, Seoul, Korea.
authors.forename: Woong Kyu
authors.initials: WK
authors.lastname: Han
keywords: Delayed graft function; Kidney; Living donors; Organ size; Transplantation