Ex-vivo Haemodynamic Models for the Study of Stanford Type B Aortic Dissection in Isolated Porcine Aorta

Abstract

Porcine aortas may prove to be useful ex-vivo models in the study of aortic dissection haemodynamics. These models are reproducible and may be used in the study of complex haemodynamic forces during the development and propagation of TBAD. Our three porcine models give a potential possibility in helping clinicians isolate and analyse complex haemodynamical factors in the development, propagation and prognosis of TBAD.

Human ex-vivo model of Stanford type B aortic dissection

“…15,[22][23][24][25][26] Most of the reported models had a limited dissection to the thoracic aorta 7,8,11,13 or did not specify the extension of the dissection (Table III). 6,9,12 In a dog model reported by Tang et al, three dissections out of 20 (15%) reach the renal aorta. Furthermore, this model was complex and time-consuming with a 25% rate of procedural failure as well as requiring an adrenaline injection with the risk of renal failure or intestinal necrosis.…”

“…Lately, several animal or physical models [5][6][7][8][9][10][11][12][13][14][18][19][20] of aortic dissection have been created to assess or improve current and new treatment methods for TBAD. However, these models have some limitations.…”

“…Furthermore, abdominal aortic side branches were responsible for distal re-entries in 80% (n ¼ 16), and have proven to be anatomic barriers against both aneurysmal and distal expansion of dissection in most cases, since it has been previously demonstrated that distal re-entries were associated with lower pressure in the false channel. 12 Regarding the stretch of the dissection propagation on the aortic circumference, all the induced dissections stretched on an hemi-circumference of the aortic wall, from the primary entry tear to the first distal re-entry tear. This invariable stretch of the FL was probably in relation with the invariable size of the created primary entry tear, which was hemi-circumferential, and the fact that it was healthy aortas.…”

“…With this aim, several swine and dog models have been reported. [4][5][6][7][8][9][10][11][12][13][14] These models may have limitations, especially regarding the aortic diameter and distal extension of the dissection. Actually, in animal models, the dissection uncommonly reaches the infraceliac aorta, 10,14 whereas in humans, the infrarenal aorta is involved in up to 70% of the cases of TBAD.…”

When Surgeons Create Their Own Tools!

“…Several models of aortic dissection have already been developed, but haemodynamic evaluation has been doubtful: dissection flaps were often unpredictable and inconsistent, either being very short in length or with undefined propagation and low reproducibility, in subsequent experiments. 3 In their paper, El Batti et al assessed the validity of the model using haemodynamic criteria, giving pressure values in both lumens and their change after fenestration. It may be criticised that the relatively short and small channel of dissection did not include visceral artery ostia, however, the model appeared to allow testing of endovascular fenestration scissors, even if it is unlike human pathology and does not allow valid conclusions concerning haemodynamic evaluation.…”