Aortic Aneurysm and Dissection
MEDICAL ANIMATION TRANSCRIPT: The aorta is the largest artery in your body. Your heart pumps fresh oxygen blood through your aorta to deliver oxygen and nutrients to all your organs and tissues. Your aorta is divided into two main sections, the thoracic aorta and the abdominal aorta. The thoracic aorta has four parts, the aortic root, ascending aorta, aortic arch, and descending aorta. The wall of your aorta is composed of three layers that give it strength, the intima, or inner layer, the media, or middle layer, and the adventitia, or outer layer. The elastic, muscular media prevents your blood pressure from rupturing the wall. Over time, degenerative disease may cause the media layer to break down, weakening the wall of your aorta. Blood pumping against the weakened area may cause it to bulge outward like a balloon. When this condition occurs in your chest, it is called a thoracic aortic aneurysm. These aneurysms may occur in one of several places, including the aortic root, the ascending aorta, or descending aorta. Most thoracic aneurysms have no symptoms, however, when they reach larger sizes varies symptoms may appear, depending on the severity and location of the aneurysm. Symptoms of stable thoracic aneurysms may include, shortness of breath, chest, back or abdominal pain, difficulty swallowing, and hoarseness. If the aneurysm ruptures, or dissects, more dramatic symptoms will appear including, a ripping sensation in the chest, severe pain in the back between the shoulder blades, dizziness, and difficulty walking and speaking. If you have these symptoms, you should seek immediate medical attention, as this condition is life threatening. Blood pumping against weakened aortic walls can lead to another life threatening condition, called aortic dissection, which may or may not occur within an aneurysm. Most commonly aortic dissection begins with damage to the intima layer. Blood moves through the break in the intima, separating it from the media, causing bleeding inside the wall of your aorta. As a result, a flap, called a septum, forms between the true aortic channel and false channel. From here, the blood may break through the outer layer of the aortic wall, causing an immediate life threatening condition, or it may re-enter the aorta through another tear in the intima. Over time, a blood clot may form in the false channel. An aortic dissection may be classified according its location and duration of symptoms. In the Stanford system, if you have an aortic dissection in your ascending aorta, it is called a Type A dissection. All other dissections are called Type B. The most common symptom of thoracic aortic dissection is sharp or stabbing chest pain, usually sudden and severe. If you have a Type A dissection, your most likely to feel pain in your chest. If you have a Type B dissection, your more likely to feel pain in your back than your chest. If you have these symptoms, you should seek immediate medical attention, as this is condition can be life threatening.