The aorta is the largest vessel in the human body. Sometimes, under the pressure of the blood, a breach can be created and allow the blood to pass, causing a tear in the aorta and/or its vessels. How does this happen? What are the consequences ? What treatment can be put in place?
What is an aortic dissection?
The wall of the aorta is made up of three layers: inner, middle and outer. “When the inner layer ruptures, blood passes between the middle and outer layersexplains Dr. Jean-François Renucci. The pressure is such, that it causes a tear, or dissection, of the aorta, and possibly other vessels. In the most serious cases, this can lead to a complete rupture of the aorta.“. There are two types of tearing, depending on the area where it occurs:
► Type A.”The tearing occurs from the heart, i.e. from the aortic valve, and stops before the start of the subclavian artery (the one that goes into the left arm)“, says Dr. Renucci. It can cause valve failure, and lead to aortic insufficiency.
► Ttype B.”Rupture occurs after the birth of the artery subclaviansays Dr. Renucci. It can extend to other vessels, such as those of the head, and descend towards the abdomen, and dissect the arteries of the kidneys“.
What are the clinical signs of an aortic dissection?
An aortic tear is very painful. “It is characterized by severe chest pain, notes Dr. Rannuci. They radiate to the back and, sometimes, to the abdomen“. Dissection of the aorta also causes breathing difficulties (dyspnoea) as well as vomiting. If the tear reaches the vessels of the head, it can cause loss of consciousness, or even a Cerebral Vascular Accident.
What causes an aortic dissection?
Several causes can cause this rupture:
- a severe high blood pressure and untreated (most often)
- Some rare genetic diseasessuch as Mafran syndrome or Ehlers-Danlos syndrome.
- a aortic infection (very rare)
What is the life expectancy in case of aortic dissection?
It is mainly for the A-type that the risk is great. “Aortic valve involvement is a absolute urgency for heart surgery, notes the vascular doctor. Otherwise, it causes almost instantaneous deaththe patient losing about 5L of blood per minute“, says Dr. Renucci. Type B is less at risk. Subsequently, for both types, increased monitoring, especially of blood pressure, is essential, whereby the situation can remain stable for a very long time and life expectancy is not affected.
An imaging test allows you to know at what level the tear occurred. The realization of a aortic scan with injection is the key examination. In parallel, ultrasound and chest x-ray provide an image of the heart.
What treatment to cure an aortic dissection?
Treatment will depend on the type of tear. If it is type A, a surgical intervention replaces the damaged part of the aorta with a tube. If the tear is type B, the treatment is primarily medical in order to lower blood pressure. Subsequently, surgery may be necessary: it is based on the placement of a prosthesis. “This is introduced into an artery in the thigh using a catheter. Under echo-guided control, the surgeon raises the prosthesis to the torn area, where he deploys it. He then removes the guide catheter“, says our expert.
What are the risks of sequelae of an aortic dissection?
Subsequently, there may be consequences of poor organ perfusion but usually we intervene surgically. In the medium term, the weakened aorta can dilate causing an aneurysmhence the importance of monitoring in order to carry out a specific treatment, most often by placing an endoprosthesis.
Thanks to Dr. Jean-François Renucci, vascular doctor at the CHU de la Timone, in Marseille.