title: Impact of chronic kidney disease on outcomes after abdominal aortic aneurysm repair.
abstract: OBJECTIVE
  Chronic kidney disease (CKD) is associated with increased morbidity and death after open abdominal aortic aneurysm (AAA) repair (OAR). This study highlights the effect of CKD on outcomes after endovascular AAA (EVAR) and OAR in contemporary practice.
  
  
  METHODS
  The National Surgical Quality Improvement Program (NSQIP) Participant Use File (2005-2008) was queried by Current Procedural Terminology (American Medical Association, Chicago, Ill) code to identify EVAR or OAR patients, who were grouped by CKD class as having mild (CKD class 1 or 2), moderate (CKD class 3), or severe (CKD class 4 or 5) renal disease. Propensity score analysis was performed to match OAR and EVAR patients with mild CKD with those with moderate or severe CKD. Comparative analysis of mortality and clinical outcomes was performed based on CKD strata.
  
  
  RESULTS
  We identified 8701 patients who were treated with EVAR (n = 5811) or OAR (n = 2890) of intact AAAs. Mild, moderate, and severe CKD was present in 63%, 30%, and 7%, respectively. CKD increased (P < .01) overall mortality, with rates of 1.7% (mild), 5.3% (moderate), and 7.7% (severe) in unmatched patients undergoing EVAR or OAR. Operative mortality rates in patients with severe CKD were as high as 6.2% for EVAR and 10.3% for OAR. Severity of CKD was associated with increasing frequency of risk factors; therefore, propensity matching to control for comorbidities was performed, resulting in similar baseline clinical and demographic features of patients with mild compared with those with moderate or severe disease. In propensity-matched cohorts, moderate CKD increased the risk of 30-day mortality for EVAR (1.9% mild vs 3.2% moderate; P = .013) and OAR (3.1% mild vs 8.4% moderate; P < .0001). Moderate CKD was also associated with increased morbidity in patients treated with EVAR (8.3% mild vs 12.8% moderate; P < .0001) or OAR (25.2% mild vs 32.4% moderate; P = .001). Similarly, severe CKD increased the risk of 30-day mortality for EVAR (2.6% mild vs 5.7% severe; P = .0081) and OAR (4.1% mild vs 9.9% severe; P = .0057). Severe CKD was also associated with increased morbidity in patients treated with EVAR (10.6% mild vs 19.2% severe; P < .0001) or OAR (31.1% mild vs 39.6% severe; P = .04).
  
  
  CONCLUSIONS
  The presence of moderate or severe CKD in patients considered for AAA repair is associated with significantly increased mortality and therefore should figure prominently in clinical decision making. The high mortality of AAA repair in patients with severe CKD is such that elective repair in such patients is not advised, except in extenuating clinical circumstances.
authors.affiliation: Division of Vascular and Endovascular Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Mass 02114, USA. vpatel4@partners.org
authors.forename: Virendra I
authors.initials: VI
authors.lastname: Patel
authors.forename: Robert T
authors.initials: RT
authors.lastname: Lancaster
authors.forename: Shankha
authors.initials: S
authors.lastname: Mukhopadhyay
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Aranson
authors.forename: Mark F
authors.initials: MF
authors.lastname: Conrad
authors.forename: Glenn M
authors.initials: GM
authors.lastname: LaMuraglia
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kwolek
authors.forename: Richard P
authors.initials: RP
authors.lastname: Cambria
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000150:complications* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000401:mortality*; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome