title: Preoperative variables predict persistent type 2 endoleak after endovascular aneurysm repair.
abstract: OBJECTIVE
  Persistent type 2 endoleaks (PT2, present >or=6 months) after endovascular aneurysm repair (EVAR) are associated with adverse outcomes. This study evaluated the preoperative risk factors and natural history of PT2 in order to define a population at high risk.
  
  
  METHODS
  From January 1999 to December 2007, 595 of 832 EVAR patients had long-term computed tomography follow-up and comprised the study cohort. Preoperative anatomic and clinical variables were correlated with PT2 using Cox regression. Composite hazard ratios (HRs) were constructed with clusters of high-risk preoperative variables. Primary end points, including spontaneous resolution, sac enlargement >5 mm, and freedom from reintervention, were evaluated using Kaplan-Meier analysis.
  
  
  RESULTS
  There were 136 PT2 patients (23%) with a median follow-up of 34.8 months (range, 6.4-121.2 months). Positive predictive factors included patent inferior mesenteric artery (IMA; HR, 4.00; 95% confidence interval [CI], 1.62-9.90; P = .003), increasing number of patent lumbar arteries (HR, 1.24; 95% CI, 1.10-1.41; P = .0006), increasing age (HR, 1.04; 95% CI, 1.01-1.06; P = .005), and increasing luminal diameter on CT-contrast opacified lumen (HR, 1.03; 95% CI, 1.02-1.05; P = .0001). During follow-up, spontaneous PT2 resolution occurred in 34 patients (25%), sac diameter remained stable in 63 (46%), and rupture occurred in 2 (1.5%). Kaplan-Meier analysis estimated that 35.2% +/- 5.6% (95% CI, 23.8%-46.2%) of PT2 resolve spontaneously at 5 years after the index procedure. Freedom from sac enlargement >5 mm was 54.6% +/- 7.2% (95% CI, 40.6%-69.4%) at 5 years. Fifty-nine reinterventions were performed in 39 patients with PT2. Freedom from reintervention was 67.3% +/- 5.0% (95% CI, 57.0%-77.0%) at 5 years. The combination of a patent IMA and one risk factor of more than six patent lumbar arteries, maximum luminal diameter >30 mm, or age >70 years increased the odds of PT2 approximately ninefold. The combination of a patent IMA and any two risk factors increased the odds of PT2 approximately 18-fold.
  
  
  CONCLUSIONS
  Several readily identifiable preoperative variables are associated with PT2 whose natural history was benign in but 35% of patients. On the basis of the composite high-risk HRs, there is accordingly a cohort of patients in whom perioperative interventions to preclude PT2 should be considered.
authors.affiliation: Division of Vascular and Endovascular Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Abularrage
authors.forename: Robert S
authors.initials: RS
authors.lastname: Crawford
authors.forename: Mark F
authors.initials: MF
authors.lastname: Conrad
authors.forename: Hang
authors.initials: H
authors.lastname: Lee
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kwolek
authors.forename: David C
authors.initials: DC
authors.lastname: Brewster
authors.forename: Richard P
authors.initials: RP
authors.lastname: Cambria
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Lamuraglia
mesh_terms: D000046:Academic Medical Centers; D000368:Aged; D000783:Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D001900:Boston; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome