The aorta is the largest blood vessel in the human body, through which blood is transported throughout the body. After it originates from the heart, it is called the thoracic aorta in the chest and the abdominal aorta when it reaches the abdomen. The aortic wall is composed of three layers of tissue that are tightly adhered together, known as the intima, media, and adventitia.
Aortic dissection is caused by various pathological factors, such as hypertension, arteriosclerosis, congenital vascular dysplasia, etc., leading to tearing of the arterial wall intima. Blood flows through the torn intima into the middle layer of the arterial wall, forming a new protruding vascular lumen called the "false lumen", while the original vascular lumen is called the "true lumen". There is only a thin layer of arterial adventitia blocking the "false lumen" outside.
Simply put, aortic dissection refers to the rupture of a small hole in the intima of the aorta due to hypertension, emotional excitement, or pathological changes in the aorta itself. High speed blood flow passes through the small hole in the intima of the aorta and impacts the interlayer between the intima and adventitia, tearing apart the two layers of the membrane. The outer membrane of the aorta is very thin, and once it ruptures, the human body will die within a few minutes, with a very high mortality rate. Therefore, aortic dissection is known as the "human bomb".
The most common symptom of aortic dissection patients is persistent and unbearable severe pain, mainly located in the chest, back, and abdomen; Some patients may not experience significant pain during the onset of the disease, but may experience symptoms such as fainting, chest tightness, difficulty breathing, lower limb numbness, or limb paralysis.
Aortic dissection is very dangerous. After dissection occurs, the arterial wall itself is thin and fragile, and the blood is only surrounded by a thin outer membrane. If this outer membrane cannot withstand the blood pressure in the body, it will rupture, causing a massive bleeding mortality rate of almost 100%. The annual natural incidence rate is about 1/100000, more men than women. If left untreated, most cases die within hours to days after onset, with a mortality rate of 1% to 2% per hour within the first 24 hours. About 50% of patients die within two weeks of onset.
What kind of people are prone to aortic dissection? The risk factors of aortic dissection patients can be divided into acquired factors and hereditary factors. The former is mainly hypertension, autoimmune diseases, atherosclerosis, etc. Some patients are caused by infection, weight lifting, trauma, iatrogenic injury, addictive drugs or pregnancy, etc; The latter is mainly caused by Marfan syndrome and Ehlers Danlos syndrome, and some patients are caused by factors such as aortic valve bicuspid malformation and familial asymptomatic aortic dissection.
The treatment of aortic dissection mainly includes drug therapy, interventional therapy, and surgical treatment. The Stanford classification system divides aortic dissection into type A and type B, where type B refers to the rupture occurring in the descending aorta. Covered stent endovascular isolation is considered the preferred surgical method for the treatment of type B aortic dissection. It involves inserting a covered stent into the true lumen and sealing the primary rupture of the dissection, causing the blood flow in the false lumen to be lost, effectively reducing the pressure in the false lumen, and reducing the risk of aortic rupture. Its advantages include minimal trauma, less bleeding, faster recovery, and low mortality rate. It is especially suitable for elderly and those with poor overall health who cannot tolerate traditional surgery.
For Stanford type A aortic dissection, surgery is the main treatment method. Surgical treatment aims to remove intimal tears, avoid interlayer rupture causing massive bleeding, and then reconstruct the blood flow status in the area of vascular obstruction caused by intimal flap or false lumen. Surgical treatment needs to be performed under extracorporeal circulation or deep hypothermic circulatory arrest conditions. The surgical trauma is relatively high, and the incidence of complications and mortality is relatively high.
Finally, a warm reminder: If you suddenly experience severe chest pain with symptoms or signs such as tearing, knife cutting, back pain, and abdominal pain that persist and cannot be relieved, please lie down and rest immediately and call 120 emergency hotline.