title: Impact of aortic dimensions and pulse pressure on late aneurysm formation in operated type A aortic dissection. A magnetic resonance imaging study.
abstract: BACKGROUND
  Patients operated on for type A aortic dissection remain at risk of long-term aneurysm development, the main cause for late death. The aim of this study was to identify early predictors for aneurysm formation at three-years after surgery.
  
  
  METHODS
  A study group of 70 consecutive patients (52 +/- 10 years-old, 41 male), operated on for aortic dissection with replacement of the ascending segment, was evaluated prospectively for three-years. In order to detect aneurysm formation, the dimension of residual distal aortic segments was obtained soon after surgery and then annually for three years using cardiovascular magnetic resonance.
  
  
  RESULTS
  During follow-up (38 +/- 2.6 months), aneurysm was found in 25 patients (35%) involving residual segments. Larger initial dimension of segments, higher pulse pressure, lower distensibility of residual segments and the presence of a residual flap were univariately associated with aneurysm. Multivariate analysis identified the initial dimension (mm) of the descending thoracic aorta (OR 1.47, 95%CI: [1.19-1.82]) and pulse pressure (OR 1.43,95%CI: [1.10-1.86]) as independent variables for aneurysm formation. A risk score using pulse pressure and descending thoracic dimension was constructed. Patients with <or=24 points had no late aneurysm formation, while those with a score >or=45 yielded 100% of aneurysm frequency.
  
  
  CONCLUSIONS
  Type A aortic dissection treated by graft interposition is associated with a high risk of aneurysm formation. Early post-operative pulse pressure and the descending thoracic aortic dimension were independent variables and seem to be the main predictors for the outcome.
authors.affiliation: Cardiology and Cardiothoracic Surgery Service, University Hospital Santa Maria, Faculty of Medicine, Lisbon University, Lisbon, Portugal. anagalmeida@hotmail.com
authors.forename: Ana G
authors.initials: AG
authors.lastname: Almeida
authors.forename: Angelo L
authors.initials: AL
authors.lastname: Nobre
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Pereira
authors.forename: Altamiro
authors.initials: A
authors.lastname: Costa-Pereira
authors.forename: Clara
authors.initials: C
authors.lastname: Tavares
authors.forename: João
authors.initials: J
authors.lastname: Cravino
authors.forename: Mário G
authors.initials: MG
authors.lastname: Lopes
mesh_terms: D000328:Adult; D000784:Aortic Dissection / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D001013:Aorta, Thoracic / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D017545:Aortic Aneurysm, Thoracic / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D001027:Aortography / Q000379:methods*; D001794:Blood Pressure; D019917:Blood Vessel Prosthesis Implantation; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome