title: Number of Renal Columns Invaded by Tumor: A Novel Parameter for Predicting Complexity and Outcomes of Off-Clamp Open Partial Nephrectomy.
abstract: BACKGROUND
  The number of renal columns invaded by tumor (NRC) can determine the tumor complexity and perioperative outcomes of off-clamp open partial nephrectomy (OPN). We aimed to propose a novel and simple scoring system and examine the relationship between NRC and perioperative outcomes after off-clamp OPN.
  
  
  METHODS
  We retrospectively evaluated 202 patients with contrast-enhanced CT imaging who underwent off-clamp OPN between January 2008 and November 2014. The number of renal columns invaded by tumor was correlated to baseline demographics and perioperative outcomes as a categorical variable using multivariable logistic regression analysis.
  
  
  RESULTS
  The mean tumor size was 2.5 cm (±1.3 cm). The number of renal columns invaded by tumor had the highest correlation coefficients with estimated blood loss (coefficient = 0.485; p < 0.001), operative time (coefficient = 0.310; p < 0.001), postoperative drainage (coefficient = 0.307; p < 0.001), and hospital length of stay (coefficient = 0.144; p = 0.041). Multivariable logistic regression demonstrated NRC to be an independent predictor of estimated blood loss ≥500 mL, postoperative renal function, operative time, and surgical complications. This predictive ability of NRC was superior to the R.E.N.A.L. (radius exophyic/endophytic nearness anterior/posterior location) score and PADUA (preoperative aspects and dimensions used for an anatomical) score. Spearman correlation coefficient of NRC calculations between the 2 observers was 0.941 (p < 0.001).
  
  
  CONCLUSIONS
  The number of renal columns invaded by tumor is a novel, intuitive, and practical parameter that could be used to quantify renal tumor complexity and predict the risk of perioperative outcomes after off-clamp OPN. Specifically, NRC correlates with estimated blood loss, operative time, surgical complications, renal function, and conversion to on-clamp. In the future, NRC can be integrated with other parameters, such as tumor location, to assemble a new scoring system.
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Yingli
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Tingchang
authors.initials: T
authors.lastname: Bian
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Zhuoyi
authors.initials: Z
authors.lastname: Xiang
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Jianming
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Zongming
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Guomin
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China. Electronic address: wang.hang@zs-hospital.sh.cn.
authors.forename: Hang
authors.initials: H
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data; D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000601:surgery; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009392:Nephrectomy / Q000379:methods; D061646:Operative Time; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome