Wall stress analysis in small asymptomatic, symptomatic and ruptured abdominal aortic aneurysms.
OBJECTIVE
To evaluate the potential of wall stress analysis for the identification of abdominal aortic aneurysm (AAA) at elevated risk of rupture in spite of small diameter.


METHODS
Thirty patients with small AAA, 10 asymptomatic, 10 symptomatic and 10 ruptured, were included. Demographic data and results from physical examinations were recorded in a retrospective fashion. After CT-evaluation and the creation of a patient specific 3D model, wall stress was calculated using the finite element method.


RESULTS
No differences were observed in diameter between asymptomatic, symptomatic or ruptured aneurysms (5.1+/-0.2 cm vs. 5.1+/-0.2 cm vs. 5.3+/-0.2 cm respectively; p=0.57). Peak aortic wall stress at maximal systolic blood pressure is significantly higher in ruptured than asymptomatic aneurysms (51.7+/-2.4 N/cm(2) vs. 39.7+/-3.3 N/cm(2) respectively; p=0.04). Wall stress analysis at uniform blood pressure, performed to correct for higher blood pressure in the symptomatic and rupture group did not result in significant differences in peak wall stress (asymptomatic 31.7+/-2.3 N/cm(2); symptomatic 30.5+/-1.3 N/cm(2); rupture 36.7+/-4.0 N/cm(2); p=0.26).


CONCLUSIONS
Wall stress analysis at maximal systolic blood pressure is a promising technique to detect aneurysms at elevated aneurysm rupture risk. Since no significant differences were found at uniform blood pressure, the need for adequate blood pressure control in aneurysm patients is reiterated.
Truijers
M
M
Department of Vascular Surgery, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. m.truijers@chir.umcn.nl
Pol
J A
JA
Schultzekool
L J
LJ
van Sterkenburg
S M
SM
Fillinger
M F
MF
Blankensteijn
J D
JD
D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001019:Aortic Rupture / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D001794:Blood Pressure; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008499:Medical Records; D008955:Models, Cardiovascular; D009426:Netherlands; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D018570:Risk Assessment; D013314:Stress, Mechanical; D013599:Systole; D036542:Tomography, Spiral Computed; D014481:United States