title: Impact of comorbidity on complications after nephrectomy: use of the Clavien Classification of Surgical Complications.
abstract: What's known on the subject? and What does the study add? Tumour characteristics, physical status and comorbidities are considered important for surgical outcome and prognosis. The present study objectively evaluates the association between comorbidity and postoperative complications after nephrectomy for RCC, by using the modified Clavien Classification of Surgical Complications to grade complications after nephrectomy.
  
  
  OBJECTIVE
  To present a single-centre experience of open nephrectomy for lesions suspected for renal cell carcinoma (RCC), evaluating the association between comorbidity and postoperative complications using a standardized classification system for postoperative complications.
  
  
  METHODS
  Clinicopathological data of 198 patients undergoing open radical or partial nephrectomy for lesions suspected of RCC were retrospectively analysed. Comorbidity scored by the Charlson comorbidity index (CCI), body mass index, age, gender, surgical procedure and surgical history were examined as predictive factors for postoperative complications, which were scored using the modified Clavien Classification of Surgical Complications (CCSC).
  
  
  RESULTS
  The overall complication rate was 34%: 7% grade I, 15% grade II, 5% grade III, 3% grade IV and 4% grade V. Preoperative comorbidities were present in 51% of all patients. There were significantly more major complications (CCSC >2) in patients with major comorbidities (CCI >2), at 16% vs 7% (P = 0.018). Patients with high-stage RCC had significantly more severe complications than low-stage RCC (P = 0.018). In multivariable analysis, comorbidity (odds ratio [OR] 7.55, P = 0.004) and tumour stage 3-4 (OR 6.23, P = 0.007) were independent predictive factors for major complications.
  
  
  CONCLUSIONS
  Major complications occur significantly more often when major comorbidities are present. Comorbidity scores can be used in risk stratification for complications and should be considered during decision-making and counselling of patients before nephrectomy.
authors.affiliation: Department of Urology, University Medical Center Utrecht, The Netherlands.
authors.forename: Pauline M L
authors.initials: PM
authors.lastname: Hennus
authors.forename: Stephanie G C
authors.initials: SG
authors.lastname: Kroeze
authors.forename: J L H Ruud
authors.initials: JL
authors.lastname: Bosch
authors.forename: Judith J M
authors.initials: JJ
authors.lastname: Jans
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000601:surgery*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000150:complications / Q000601:surgery*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D011183:Postoperative Complications / Q000145:classification / Q000209:etiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index