Impact of aortic dimensions and pulse pressure on late aneurysm formation in operated type A aortic dissection. A magnetic resonance imaging study.
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.
Almeida
Ana G
AG
Cardiology and Cardiothoracic Surgery Service, University Hospital Santa Maria, Faculty of Medicine, Lisbon University, Lisbon, Portugal. anagalmeida@hotmail.com
Nobre
Angelo L
AL
Pereira
Ricardo A
RA
Costa-Pereira
Altamiro
A
Tavares
Clara
C
Cravino
João
J
Lopes
Mário G
MG
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