title: Differentiating reconstructive techniques in partial nephrectomy: a propensity score analysis.
abstract: BACKGROUND
  To assess whether volumetric measurements can differentiate functional changes between reconstructive techniques after partial nephrectomy.
  
  
  METHODS
  One hundred and fifty-six patients undergoing partial nephrectomy for a single renal mass were retrospectively studied between 2008 and 2012. Computed tomography scans were available for volume calculations on 56 (18 non-renorrhaphy and 38 renorrhaphy). Institutional review board approval was obtained. The primary outcome was %volume loss in the operated kidney, which was calculated from three-dimensional reconstructions using a semiautomatic segmentation algorithm. Multivariable regression and propensity score analysis was performed.
  
  
  RESULTS
  Volumetric analysis detected a difference in mean %volume loss between two-layer reconstruction (cortical renorrhaphy and base-layer) and base-layer only (15.6% versus 3.8%, p < 0.001). The mean %glomerular filtration rate (GFR) loss was also greater in the two-layer group (8.9% versus 2.4%, p = 0.03). Demographics were similar between groups except the two-layer group was older, had more males, and increased ischemia time. On multivariable regression the presence of two-layer closure (β = -15.2%, p < 0.001) and tumor diameter (β = -7.4, p = 0.004) were significant predictors of %volume loss while ischemia time (p = 0.88) was not. Two-layer closure remained a predictor on propensity-adjusted analysis (β = -14.3, p = 0.004). The base-layer only group had two (5.3%) urine leaks and two (5.3%) bleeding complications. The two-layer group had two (1.7%) urine leaks and three (2.5%) bleeding complications (p = 0.23, 0.41).
  
  
  CONCLUSIONS
  Volume loss calculated from CT scans can be used to monitor postoperative renal function. Techniques for renal reconstruction and tumor diameter are associated with volume and functional loss after partial nephrectomy and should be controlled for in future studies.
authors.affiliation: Department of Urology, Indiana University, Indianapolis, Indiana, USA.
authors.forename: Clinton D
authors.initials: CD
authors.lastname: Bahler
authors.forename: K Clint
authors.initials: KC
authors.lastname: Cary
authors.forename: Swapnil
authors.initials: S
authors.lastname: Garg
authors.forename: Eric M
authors.initials: EM
authors.lastname: DeRoo
authors.forename: Christian H
authors.initials: CH
authors.lastname: Tabib
authors.forename: Jagan K
authors.initials: JK
authors.lastname: Kansal
authors.forename: M Francesca
authors.initials: MF
authors.lastname: Monn
authors.forename: Chandra K
authors.initials: CK
authors.lastname: Flack
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Masterson
authors.forename: M Kumar
authors.initials: MK
authors.lastname: Sandrasegaran
authors.forename: Richard S
authors.initials: RS
authors.lastname: Foster
authors.forename: Chandru P
authors.initials: CP
authors.lastname: Sundaram
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D021621:Imaging, Three-Dimensional; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects / Q000379:methods*; D009929:Organ Size; D057216:Propensity Score; D012189:Retrospective Studies; D013536:Suture Techniques; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden; D052096:Warm Ischemia