title: Defining risk and identifying predictors of mortality for open conversion after endovascular aortic aneurysm repair.
abstract: OBJECTIVE
  Risk of open conversion after endovascular aortic aneurysm repair (EVAR-c) is poorly defined. The purpose of this analysis was to determine outcomes of elective EVAR-c compared with elective primary open abdominal aortic aneurysm repair (PAR) in the Vascular Quality Initiative.
  
  
  METHODS
  Vascular Quality Initiative patients who underwent elective EVAR-c and PAR (2002-2014) were reviewed. Candidate predictors of major adverse cardiac event (MACE) and/or 30-day mortality were entered into a multivariable model, and stepwise elimination was used to reduce the number of covariates to a best subset of predictors. To estimate the additive risk of EVAR-c for MACE or 30-day mortality over PAR, this variable was added along with the best subset of predictors into generalized estimating equations logistic regression models.
  
  
  RESULTS
  We identified 159 EVAR-c and 3741 PAR patients. EVAR-c patients were older (73.5 ± 8.1 vs 69.5 ± 8.4 years; P < .0001), more likely to have diabetes (21% vs 15%; P = .03), and history of lower extremity bypass (9% vs 4%; P = .0006). EVAR-c was associated with a higher incidence of retroperitoneal aortic exposure (41%; n = 64 vs PAR, 26%, n = 976; P < .0001), use of a bifurcated graft (65%; n = 101 vs PAR, 52%; n = 1923; P = .001), greater blood loss (median [interquartile range], 2000 mL [1010-3500] vs PAR, 1200 mL [750-2000]; P < .0001) and longer procedure times (EVAR-c, 275 ± 122 minutes vs PAR, 232 ± 9 minutes; P < .0001). However, PAR more frequently was completed with a suprarenal and/or mesenteric cross-clamp (74%, n = 2749 vs EVAR-c, 53%, n = 83; P < .0001) and had a higher incidence of concomitant procedures (26%; n = 972 vs EVAR-c, 18%; n = 28; P = .03). Nonadjusted 30-day mortality was greater after EVAR-c: EVAR-c, 8% (n = 10) vs PAR, 3% (n = 105); P = .009. There was no difference in complication rates: EVAR-c, 33% (n = 52) vs PAR, 28% (n = 1056); P =.3. Preoperative 30-day mortality predictors included age (odds ratio [OR], 1.06/y, 95% confidence interval [CI], 1.04-1.1; P < .0001), chronic obstructive pulmonary disease (OR, 2.4; 95% CI, 1.6-3.5; P < .0001), history of leg bypass (OR, 2.3, 1.2-4.4;P =.01), suprarenal cross-clamp (OR 2.2, 1.2-4.1;P =.01), prior carotid revascularization (OR 2.2; 95% CI, 1.3-3.8; P = .0004), congestive heart failure (OR, 1.8; 95% CI, 0.9-3.5; P = .08), and female sex (OR, 1.6; 95% CI, 1.1-2.3; P = .02; area under the curve, 0.75). When controlling for covariates, EVAR-c was not significantly associated with MACE (OR, 1.2; 95% CI, 0.7-2.0; P = .4) or 30-day mortality (OR, 2.0; 0.9-4.2; P = .08).
  
  
  CONCLUSIONS
  EVAR-c patients are typically older, have more comorbidities, and experience greater blood loss and longer procedure times compared with PAR patients. However, postoperative morbidity and mortality are primarily driven by patient covariates and intraoperative factors, rather than the need for endograft explantation. Several preoperative variables were identified as predictors of 30-day mortality after elective EVAR-c and should be considered during the decision-making process for remedial treatment of failed endovascular PAR.
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida College of Medicine, Gainesville, Fla. Electronic address: salvatore.scali@surgery.ufl.edu.
authors.forename: Salvatore T
authors.initials: ST
authors.lastname: Scali
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida College of Medicine, Gainesville, Fla.
authors.forename: Adam W
authors.initials: AW
authors.lastname: Beck
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida College of Medicine, Gainesville, Fla.
authors.forename: Catherine K
authors.initials: CK
authors.lastname: Chang
authors.affiliation: Society for Vascular Surgery Vascular Quality Initiative Patient Safety Organization, Chicago, Ill.
authors.forename: Dan
authors.initials: D
authors.lastname: Neal
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida College of Medicine, Gainesville, Fla.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Feezor
authors.affiliation: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
authors.forename: David H
authors.initials: DH
authors.lastname: Stone
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida College of Medicine, Gainesville, Fla.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Berceli
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida College of Medicine, Gainesville, Fla.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Huber
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D019985:Benchmarking; D016063:Blood Loss, Surgical / Q000401:mortality; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000401:mortality*; D016009:Chi-Square Distribution; D015897:Comorbidity; D061887:Conversion to Open Surgery / Q000009:adverse effects / Q000401:mortality*; D016208:Databases, Factual; D017558:Elective Surgical Procedures; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D061646:Operative Time; D011183:Postoperative Complications / Q000401:mortality*; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States