Table 1

Severity parameters for AAA rupture
BFi
Definition
 Reported ranges of biomechanical factors (BFi )
 Weighing coefficients wi
References for BFi -ranges






Low risk
 Middle risk
 High risk
 Danger zone

i = 1: Diameter ratio
1.5~1.9
 2.0~2.4
 2.5~3.2
 ≥3.3
 0.20
 Cappeller [6]
i = 2: Expansion rate (per year)
0.01~0.04
 0.05~0.09
 0.10~0.17
 ≥0.18
 0.25
 Limet [2]
i = 3: Stress ratio
1.5~2.0
 2.1~3.0
 3.1~4.3
 ≥4.4
 0.15
 Fillinger [4]
i = 4: Diastolic pressure ratio
0.83~0.9
 0.91~1.0
 1.1~1.16
 ≥1.17
 0.12
 Cronenwett [20]
i = 5: Asymmetry index
1~0.9
 0.7~0.8
 0.5~0.6
 ≤0.4
 0.07
 Vorp [36]
i = 6: ILT-AAA ratio
0.1~0.24
 0.25~0.44
 0.45~0.61
 ≥0.62
 0.07
 Cappeller [6]
i = 7: Stiffness decrease (per year)
0.01~0.03
 0.04~0.06
 0.07~0.09
 ≥0.1
 0.07
 Wilson [23]
i = 8: Saccular index
≥0.71
 0.66~0.70
 0.61~0.65
 ≤0.6
 0.07
 Ouriel [41]
Assigned BFi threshold values
 0.1
 0.3
 0.7
 1.0

Kleinstreuer and Li BioMedical Engineering OnLine 2006 5:19   doi:10.1186/1475-925X-5-19