Vliv porušení intraluminárního trombu na mechanické napětí ve stěně výdutě břišní aorty

The impact of Intra-luminal Thrombus failure on the mechanical stress in the wall of Abdominal Aortic Aneurysms

článek v časopise - ostatní, Jost

en

The role of the Intra-luminal Thrombus (ILT) in Abdominal Aortic Aneurysm (AAA) rupture is controversial and it is still not clear if an ILT increases or decreases AAA rupture risk. Specifically, signs of bleeding in the ILT are thought to increase AAA rupture risk. In order to further investigate this hypothesis, intact AAAs (n=4) with clear signs of ILT rupture in Computer Tomography Angiography (CT-A) images were investigated. To this end two cases were investigated: an ILT failure extracted directly from the CT-A data and a hypothetical ILT fissure connecting the lumen with the underlying aneurysm wall. Wall stress distributions were predicted based on the detailed Finite Element (FE) models. The study showed that the ILT rupture, as extracted from the CT-A data, can increase the mechanical stress in the underlying wall by up to 30%. The largest impact on the wall stress was observed if the ILT failure reaches the aneurysm wall or if it involves large parts of the ILT. In contrast, a concentric failure in the medial ILT not reaching the wall has almost no impact on the wall stress distribution. Finally, the insertion of the hypothetical crack in the ILT can even double the stress of the underlying wall. In conclusion, the ILT failure redistributes the wall stress and, if it reaches the wall or involves large parts of the ILT, it can potentially trigger the AAA rupture.

Je posuzována výpočtovým modelováním kontroverzní role intraluminálního trombu na napětí ve stěně a riziko ruptury aneurysmatu abdominální aorty. Kokrétně je zvažováno, zda známky ruptury trombu, projevující se pronikáním krve do trombu zvyšují riziko ruptury stěny aneurysmatu. K potvrzení této hypotézy byla modelována 4 intaktní aneurysmata s jasnými známkami ruptury trombu na CT-A snímcích. Modelovány byly dva případy: skutečná trhlina v trombu zjištěná z CT-A a hypotetická trhlina probíhající od lumen po arteriální stěnu. Analýza napětí ve stěně ukazuje, že vlivem trhliny v trombu dochází k redistribuci napětí, která je silně závislá na tvaru trhliny a v různé míře přispívá ke zvýšení rizika ruptury aneurysmatu.

The role of the Intra-luminal Thrombus (ILT) in Abdominal Aortic Aneurysm (AAA) rupture is controversial and it is still not clear if an ILT increases or decreases AAA rupture risk. Specifically, signs of bleeding in the ILT are thought to increase AAA rupture risk. In order to further investigate this hypothesis, intact AAAs (n=4) with clear signs of ILT rupture in Computer Tomography Angiography (CT-A) images were investigated. To this end two cases were investigated: an ILT failure extracted directly from the CT-A data and a hypothetical ILT fissure connecting the lumen with the underlying aneurysm wall. Wall stress distributions were predicted based on the detailed Finite Element (FE) models. The study showed that the ILT rupture, as extracted from the CT-A data, can increase the mechanical stress in the underlying wall by up to 30%. The largest impact on the wall stress was observed if the ILT failure reaches the aneurysm wall or if it involves large parts of the ILT. In contrast, a concentric failure in the medial ILT not reaching the wall has almost no impact on the wall stress distribution. Finally, the insertion of the hypothetical crack in the ILT can even double the stress of the underlying wall. In conclusion, the ILT failure redistributes the wall stress and, if it reaches the wall or involves large parts of the ILT, it can potentially trigger the AAA rupture.

intraluminární trombus, riziko ruptury, aneurysma břišní aorty, MKP analýza.

Intra-luminal Thrombus, failure risk, finite element analysis, Abdominal Aortic Aneurysms

2011

18.02.2011

Elsevier

1078-5884

EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY

41

4

467–473

7