Aortic Arch & Thoracic descending Aorta Aneurysm
Causes and risk factors
The causes of aortic aneurysms development can be congenital, in presence of elastopathy (e.g. Marfan syndrome, Ehlers-Danlos syndrome, Loeys-Dietz syndrome), degenerative, inflammatory, infected or mechanical. The thoracoabdominal aneurysms can be sometimes as a result of a chronical aortic dissection. The risk factors are a previous acute aortic dissection who underwent ascending aorta replacement, a family history of aortic aneurysms, bicuspid valve or connective tissue disorder, smoking, dislipidemia and high blood pressure.
Which are the symptoms?
Many patients with thoracic aortic aneurysms are asymptomatic at presentation and the aneurysms are detected during testing fot other disorders or in course of follow-up for previous aortic surgery. Symptoms relating to the aneurysm usually develop later in the course of enlargement of the aorta and result from impingement of the aneurysm on adjacent structures. Patients with aneurysms involving the aortic arch may present with pain in the neck and jaw. Hoarseness results from stretching of the left recurrent laryngeal nerve, stridor form compression of the trachea, dysphagia from impingement on the esophageus lumen, dyspnea from compression of the lung parenchima, plethora and edema from compression of the superior vena cava. Aneurysms of the thoracoabdominal aorta may be associated with back pain, abdominal pain and pain in the left shoulder due to irritation of the left hemidiafragm.
- Anterior or posterior chest pain
- Plethora and edema
- Abdominal pain
- Left shoulder pain
How is it diagnosed?
Findings on the chest radiograph may be rarely diagnostic of a ascending aortic aneurysm or a thoracic aortic aneurysm in general. CT scan with the use of contrast is the most widely used non invasive technique for diagnosing thoracic aortic disease. It provides information about size, location and extent of the aneurysm; it is of particular value in documenting the growth rate of aneurysms, determining timing of operative intervention in asymptomatic patients and evaluating patients postoperatively. Others diagnostic techniques are MRI, TEE and aortography.
How is it treated?
The surgical treatment of the aortic arch aneurysm consists in excising the aneurysm and replace it with a prosthetic tube graft. The aortic arch replacement can be partial or total. The supra-aortic vessels, that carries the oxygenated blood to the brain and upper limbs, are sutured to the graft with a single arterial button or separately, using a branched graft. Hypotermic circulatory arrest with moderate hypotermia (26 Celsius degrees) should be established in case of aortic arch surgery with cerebral protection, most of the times, with bilateral perfusion during the circulatory arrest time. When the aneurysm involves more the just the very proximal descending thoracic aorta, a two-stage procedure may be considered. Surgical management of extensive arch disease involving the descending aorta can be achieved with an hybrid approach called "Frozen Elephant Trunk" (FET) which allows to to treat the combined disease of the arch and of the descending thoracic aorta at the same surgical time (one-stage approach) using an hybrid prosthesis composed of a proximal part consisting of a a vascular prosthetic graft and a distal part consisting of a self-expandable stent graft. In addiction, after performing FET technique, it is possible to use the stent graft as a landing zone for secondary endovascular extension. The aortic arch surgery surgical approach is performed with a traditional full median sternotomy.
Page edited by: Carlo De Vincentiis