Posouzení rizika ruptury aneurysmat břišní aorty na základě nového pravděpodobnostního risk indexu

Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index

článek v časopise ve Web of Science, Jimp

en

Background. A rupture risk assessment is critical to the clinical treatment of Abdominal Aortic Aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. Methods. The present study derives a Probabilistic Rupture Risk Index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n=7) and intact (n=7) AAAs and compared to alternative risk assessment methods. Results. Computed PRRI at 1.5 Mean Arterial Pressure was significantly (p=0.041) higher in ruptured AAAs (20.21(SD14.15%) than in intact AAAs (3.71(SD 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and Peak Wall Stress (PWS) had only negligible effects on PRRI computations. Conclusion. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modeling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach.

Hodnocení rizika ruptury aneurysmat abdominální aorty (AAA) je kritická část léčby tohoto onemocnění. Je navrže a validován nový riskindex, který poprvé zahrnuje nejistoty v tloušťce stěny a pevnosti stěny jako integrální součást hodnocení rizika ruptury. Tento index byl porovnán s dalším dostupným způsobem hodnocení a byla prokázana jeho významně lepší citlivost.

Background. A rupture risk assessment is critical to the clinical treatment of Abdominal Aortic Aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. Methods. The present study derives a Probabilistic Rupture Risk Index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n=7) and intact (n=7) AAAs and compared to alternative risk assessment methods. Results. Computed PRRI at 1.5 Mean Arterial Pressure was significantly (p=0.041) higher in ruptured AAAs (20.21(SD14.15%) than in intact AAAs (3.71(SD 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and Peak Wall Stress (PWS) had only negligible effects on PRRI computations. Conclusion. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modeling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach.

abdominal aortic aneurysm; uncertainty; model finite element; failure; wall stress;

2015

02.12.2015

Royal Society Publishing

London, Great Britain

1742-5689

113

12

1–11

11