title: Aortic curvature as a predictor of intraoperative type Ia endoleak.
abstract: OBJECTIVE
  Hostile infrarenal neck characteristics are associated with complications such as type Ia endoleak after endovascular aneurysm repair. Aortic neck angulation has been identified as one such characteristic, but its association with complications has not been uniform between studies. Neck angulation assumes triangular oversimplification of the aortic trajectory, which may explain conflicting findings. By contrast, aortic curvature is a measurement that includes the bending rate and tortuosity and may provide better predictive value for neck complications.
  
  
  METHODS
  Data were retrieved from the Heli-FX (Aptus Endosystems, Inc, Sunnyvale, Calif) Aortic Securement System Global Registry (ANCHOR). One cohort included patients who presented with intraoperative endoleak type Ia at the completion angiogram as the indication for EndoAnchors (Aptus Endosystems), and a second cohort comprised those without intraoperative or late type Ia endoleak (controls). The aortic trajectory was divided into six segments with potentially different influence on the stent graft performance: suprarenal, juxtarenal, and infrarenal aortic neck (-30 to -10 mm, -10 to 10 mm, and 10-30 mm from the lowest renal artery, respectively), the entire aortic neck, aneurysm sac, and terminal aorta (20 mm above the bifurcation to the bifurcation). Maximum and average curvature were automatically calculated over the six segments by proprietary custom software. Aortic curvature was compared with other standard neck characteristics, including neck length, neck diameter, maximum aneurysm sac diameter, neck thrombus and calcium thickness and circumference, suprarenal angulation, infrarenal angulation, and the neck tortuosity index. Independent risk factors for intraoperative type Ia endoleak were identified using backwards stepwise logistic regression. For the variables in the final regression model, suitable cutoff values in relation to the prediction of acute type Ia endoleak were defined with the area under the receiver operating characteristic curve.
  
  
  RESULTS
  The analysis included 64 patients with intraoperative type Ia endoleak and 79 controls. Logistic regression identified only aortic neck calcification and aortic curvature, expressed over the juxtarenal aortic neck, the aneurysm sac, and the terminal aorta, as independent predictors of intraoperative type Ia endoleak.
  
  
  CONCLUSIONS
  Together with aortic neck calcification, aortic curvature appears to be the best predictor of intraoperative type Ia endoleak, as expressed within the juxtarenal aortic neck, the aneurysm sac, and the terminal aorta. Aortic neck angulation was not a predictor for acute failure. Aortic curvature may provide a better anatomic characteristic to define patients at risk for early complications after endovascular aneurysm repair.
authors.affiliation: Technical Medicine, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands; Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands. Electronic address: richte.schuurmann@gmail.com.
authors.forename: Richte C L
authors.initials: RC
authors.lastname: Schuurmann
authors.affiliation: Syntactx, New York, NY.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Ouriel
authors.affiliation: Vascular and Endovascular Surgery, Yale School of Medicine, New Haven, Conn.
authors.forename: Bart E
authors.initials: BE
authors.lastname: Muhs
authors.affiliation: Vascular Surgery and Endovascular Therapy, University of Alabama, Birmingham, Ala.
authors.forename: William D
authors.initials: WD
authors.lastname: Jordan
authors.affiliation: Syntactx, New York, NY.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ouriel
authors.affiliation: Technical Medicine, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands; Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Boersen
authors.affiliation: Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Jean-Paul P M
authors.initials: JP
authors.lastname: de Vries
mesh_terms: D000407:Alabama; D001014:Aortic Aneurysm / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003237:Connecticut; D057867:Endoleak / Q000175:diagnosis / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects* / Q000295:instrumentation; D006801:Humans; D016015:Logistic Models; D015999:Multivariate Analysis; D009426:Netherlands; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D011857:Radiographic Image Interpretation, Computer-Assisted; D012042:Registries; D012307:Risk Factors; D015607:Stents; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D061205:Vascular Calcification / Q000150:complications / Q000175:diagnosis / Q000601:surgery*