The Roles of Intraluminal Pressure and the Dilation of Tunica Media in the Development of Aortic Dissection

Aortic dissection is defined as the separation of aortic medial lamellae. It is unknown why some aortic dissection are limited in extent while other aortic dissection extend extensively. The investigators hypothesize that the medial layers are separated as a result of the uneven dilation and dislocation of the inner and outer layers, and if this hypothesis is ture, dilation is necessary to the development of aortic dissection. In this study, an in vitro experiment was performed to test whether dilation is essential to the development of aortic dissection.

Participants will be recruited from patients with aortic repair surgery in Wuhan Asian Heart Hospital. A piece of aortic wall will be dissected to reconstruct aorta during operation. Firstly, the dissected aortic wall is sampled for routine pathological examination. Secondly, the remaining tissue is cut into a 2cm by 2cm sheet, then an incision was made on the inner surface of the tissue sheet. The outer 0.5mm media will not be incised. Thirdly, the tissue sheet is used to seal a hole in a syringe with the incision faced inside, and tissue sheet of the experimental group was bound by a band to restrict its dilation in the next step. Fourthly, the syringe is filled with blue stain, and a mechanical test is performed. Fifthly, for the experimental group, the band is removed, and the syringe is filled with red stain. The mechanical test is performed again. Finally, the tissue sheet is released and cut into several parts to show whether the inner and outer media layers are separated by the blue stain or the red stain.