title: Endovascular repair of abdominal aortic aneurysms: risk stratified outcomes.
abstract: OBJECTIVE
  The impact of co-morbid conditions on early and late clinical outcomes after endovascular treatment of abdominal aortic aneurysm (AAA) was assessed in concurrent cohorts of patients stratified with respect to risk for intervention.
  
  
  BACKGROUND
  As a minimally invasive strategy for the treatment of AAA, endovascular repair has been embraced with enthusiasm for all prospective patients who are suitable anatomical candidates because of the promise of achieving a durable result with a reduced risk of perioperative morbidity and mortality.
  
  
  METHODS
  From April 1994 to March 2001, endovascular AAA repair was performed in 236 patients using commercially available systems. A subset of patients considered at increased risk for intervention (n = 123) were categorized, as such, based on a preexisting history of ischemic coronary artery disease, with documentation of myocardial infarction (60%) or congestive heart failure (35%), or due to the presence of chronic obstructive disease (21%), liver disease, or malignancy.
  
  
  RESULTS
  Perioperative mortality (30-day) was 6.5% in the increased-risk patients as compared to 1.8% among those classified as low risk (P = NS). There was no difference between groups in age (74 +/- 9 years vs. 72 +/- 6 years; mean +/- SD), surgical time (235 +/- 95 minutes vs. 219 +/- 84 minutes), blood loss (457 +/- 432 mL vs. 351 +/- 273 mL), postoperative hospital stay (4.8 +/- 3.4 days vs. 4.0 +/- 3.9 days), or days in the ICU (1.3 +/- 1.8 days vs. 0.5 +/- 1.6 days). Patients at increased risk of intervention had larger aneurysms than low-risk patients (59 +/- 13 mm vs. 51 +/- 14 mm; P <.05). Stent grafts were successfully implanted in 116 (95%) increased-risk versus 107 (95%) low-risk patients (P = NS). Conversion rates to open operative repair were similar in increased-risk and low-risk groups at 3% and 5%, respectively. The initial endoleak rate was 22% versus 20%, based on the first CT performed (either at discharge or 1 month; P = NS). To date, increased-risk patients have been followed for 17.4 +/- 15 months and low-risk patients for 16.3 +/- 14 months. Kaplan-Meier analysis for cumulative patient survival demonstrated a reduced probability of survival among those patients initially classified as at increased risk for intervention (P <.05, Mantel-Cox test). Both cohorts had similar two-year primary and secondary clinical success rates of approximately 75% and 80%, respectively.
  
  
  CONCLUSIONS
  Early and late clinical outcomes are comparable after endovascular repair of AAA, regardless of risk-stratification. Notably, 2 years after endovascular repair, at least one in five patients was classified as a clinical failure. Given the need for close life-long surveillance and the continued uncertainty associated with clinical outcome, caution is dictated in advocating endovascular treatment for the patient who is otherwise considered an ideal candidate for standard open surgical repair.
authors.affiliation: Division of Vascular Surgery, Emory University School of Medicine, Atlanta, Georgia 30332, USA. echaiko@emory.edu
authors.forename: Elliot L
authors.initials: EL
authors.lastname: Chaikof
authors.forename: Peter H
authors.initials: PH
authors.lastname: Lin
authors.forename: William T
authors.initials: WT
authors.lastname: Brinkman
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Dodson
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Weiss
authors.forename: Alan B
authors.initials: AB
authors.lastname: Lumsden
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Terramani
authors.forename: Sasan
authors.initials: S
authors.lastname: Najibi
authors.forename: Ruth L
authors.initials: RL
authors.lastname: Bush
authors.forename: Atef A
authors.initials: AA
authors.lastname: Salam
authors.forename: Robert B
authors.initials: RB
authors.lastname: Smith
mesh_terms: D000368:Aged; D017130:Angioplasty / Q000009:adverse effects; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000379:methods*