title: An Arterial Based Complexity (ABC) Scoring System to Assess the Morbidity Profile of Partial Nephrectomy.
abstract: BACKGROUND
  Tumor characteristics affect surgical complexity and outcomes of partial nephrectomy (PN).
  
  
  OBJECTIVE
  To develop an Arterial Based Complexity (ABC) scoring system to predict morbidity of PN.
  
  
  METHODS
  Four readers independently scored contrast-enhanced computed tomography images of 179 patients who underwent PN.
  
  
  METHODS
  Renal cortical masses were categorized by the order of vessels needed to be transected/dissected during PN. Scores of 1, 2, 3S, or 3H were assigned to tumors requiring transection of interlobular and arcuate arteries, interlobar arteries, segmental arteries, or in close proximity of the renal hilum, respectively during PN.
  
  
  METHODS
  Interobserver variability was assessed with kappa values and percentage of exact matches between each pairwise combination of readers. Linear regression was used to evaluate the association between reference scores and ischemia time, estimated blood loss, and estimated glomerular filtration rates at 6 wk and 6 mo after surgery adjusted for baseline estimated glomerular filtration rate. Fisher's exact test was used to test for differences in risk of urinary fistula formation by reference category assignment.
  
  
  CONCLUSIONS
  Pairwise comparisons of readers' score assignments were significantly correlated (all p<0.0001); average kappa = 0.545 across all reader pairs. The average proportion of exact matches was 69%. Linear regression between the complexity score system and surgical outcomes showed significant associations between reference category assignments and ischemia time (p<0.0001) and estimated blood loss (p=0.049). Fisher's exact test showed a significant difference in risk of urinary fistula formation with higher reference category assignments (p=0.028). Limitations include use of a single institutional cohort to evaluate our system.
  
  
  CONCLUSIONS
  The ABC scoring system for PN is intuitive, easy to use, and demonstrated good correlation with perioperative morbidity.
  
  
  RESULTS
  The ABC scoring system is a novel anatomy-reproducible tool developed to help patients and doctors understand the complexity of renal masses and predict the outcomes of kidney surgery.
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Massimiliano
authors: M
authors: Spaliviero
authors: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Bing Ying
authors: BY
authors: Poon
authors: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Christoph A
authors: CA
authors: Karlo
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Giuliano B
authors: GB
authors: Guglielmetti
authors: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Pier Luigi
authors: PL
authors: Di Paolo
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Renato
authors: R
authors: Beluco Corradi
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Alexandre G
authors: AG
authors: Martin-Malburet
authors: Hospital Universitario Marques de Valdecilla, Santander, Spain.
authors: Felix
authors: F
authors: Campos-Juanatey
authors: Hospital General Universitario de Valencia, Valencia, Spain.
authors: Eva
authors: E
authors: Escudero-Fontano
authors: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Daniel D
authors: DD
authors: Sjoberg
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Paul
authors: P
authors: Russo
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Jonathan A
authors: JA
authors: Coleman
authors: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors: Oguz
authors: O
authors: Akin
authors: Urology Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA. Electronic address: touijera@mskcc.org.
authors: Karim A
authors: KA
authors: Touijer
mesh_terms: D000368:Aged; D001158:Arteries / Q000601:surgery*; D016063:Blood Loss, Surgical; D003287:Contrast Media; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000098:blood supply*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects* / Q000379:methods; D015588:Observer Variation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014548:Urinary Fistula / Q000209:etiology*; D052096:Warm Ischemia
chemical_list: D003287:Contrast Media
keywords: Kidney neoplasms; Nephrometry; Observer variation; Outcome assessment; Partial nephrectomy