The main objective is to compare the mitochondrial dynamic between patients operated for aneurysm of ascending aorta or type A aortic dissection (AAD) or control group

In an aortic aneurysm process, the alteration of the extracellular matrix (ECM) as well as the apoptosis of the smooth muscle cells are due to inflammatory phenomena and oxydative stress, involving mitochondria which has a key place within cells.

Mitochondrial fusion and fission constitute mitochondrial dynamic and are involved in the mechanisms described above.

The alteration of mitochondrial dynamics has been demonstrated in many pathologies, in particular neurological, cancer and cardiovascular disease and generally occurs in favor of fission.

In a mouse model (FASEB J, 2021, Robert P ), the role of mitochondrial fusion has been demostrated as a protective factor against hypertension in resistance arteries and a deletion of OPA1 (optic Atrophy 1) fusion protein may lead to aneurysm until aortic dissection. The results of this experimental study suggest a role of the alteration of mitochondrial dynamic in the development of aneurysm and aortic dissection.

Inclusion Criteria:

• Aneurysm aortic group: patients treated for an aneurysm of the ascending thoracic aorta with surgical indication according to the ESC guidelines (2014).
• Aortic dissection group: patients treated for type A acute aortic dissection or intramural hematoma of the ascending thoracic aorta in emergency.
• Control group: patients operated for aortic valve replacement (little aortic sample before closing aortotomy) or coronary artery bypass grafting which the use of a saphenous graft and the performance of a proximal anastomosis on the ascending aorta is planned

Exclusion Criteria:

• Patients under 18 years old
• Other acute aortic syndromes (penetrating ulcers, iatrogenic or traumatic dissections)
• Patients treated for aortic valve replacement in the context of infective endocarditis
• Patients treated for emergency aortic valve replacement or coronary bypass surgery**
• Pregnant, parturient and breastfeeding women
• Patients protected by an administrative or judicial measure (curatorship, guardianship)
• Patients receiving psychiatric care under duress
• Adults subject to a legal protection measure.
• Patients whose the samples planned for the study could not be taken;
• Patients in the control group whose tissue sampling will not be performed.

The data will be collected in a coded manner: first letter of the surname, first letter of the patient's first name, serial number of inclusion in the center by the physicians investigating the study in the electronic observation notebook managed by the DRCI of University Hospital of Angers