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

Study Overview
=================
Brief Summary
-----------------
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.

Detailed Description
-----------------
The mechanical test: the syringe's pressure will increase gradually to a target level, and then decrease gradually to 0 Mpa, and this process is repeated for about 60 times.

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

Conditions
-----------------
Aortic Dissection

Intervention / Treatment
-----------------
* Diagnostic Test: the aortic delamination test


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: patients with aortic repair surgery. Exclusion Criteria: the dissected aortic wall is not big enough to be cut into a 2cm by 2cm sheet after routine pathological examination.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| experimental group<br>In this group, the specimen of aortic wall is bound by a band to restrict its dilation in the fourth step of the aortic delamination test. | Diagnostic Test: the aortic delamination test<br>* The aortic delamination test will be performed in the dissected tissue of all patient. The processes of this test has been descripted in the summary.<br>|
| control group<br>In this group, the specimen of aortic wall is not bound by a band to restrict its dilation in the fourth step of the aortic delamination test. | Diagnostic Test: the aortic delamination test<br>* The aortic delamination test will be performed in the dissected tissue of all patient. The processes of this test has been descripted in the summary.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The number of patients with a positive result of the aortic delamination test | whether the inner and outer media layers are separated by the blue stain or the red stain. | 1 month |