The aorta is the thickest artery in the human body, originating from the left ventricle of the heart and branching out during its course to supply all organs and tissues in the body.
The tissue structure of the aortic wall is like a common plywood, divided into three layers: intima, media, and adventitia.
The occurrence of dissection occurs when a rupture is created in the intima of the aorta, causing blood to break through to the media and tear the aorta into layers. The vascular lumen is divided into a true lumen and a false lumen, leaving only a thin outer membrane surrounding the entire vessel wall.
This is a very unstable state because the outer membrane can rupture at any time. Once the outer membrane cannot withstand the pressure of blood and ruptures, the consequences can be fatal.
According to the extent of aortic dissection, it can be divided into two types: A and B. Among them, type A aortic dissection is the more dangerous type because it involves the ascending aorta.
According to statistics, the mortality rate of acute Stanford type A aortic dissection without surgical treatment is as high as 50% within 24 hours of onset, and the mortality rate increases by 1% to 2% per hour thereafter. The mortality rate exceeds 70% within one week.
Risk factors for aortic dissection
Hypertension is the most important risk factor for aortic dissection. According to statistical data, 50.1% -75.9% of patients with aortic dissection have a history of hypertension.
On the one hand, hypertension can promote the development of atherosclerosis and affect the quality of the arterial wall. On the other hand, the persistent high pressure blood flow repeatedly impacts, making the arterial wall more vulnerable to damage.
There are also some genetic diseases, such as Marfan and Enler Danlos syndrome with inherited connective tissue defects, which expose many young and middle-aged people to the risk of aortic dissection.
Pregnancy is a special risk factor, with 50% of women who suffer from aortic dissection before the age of 40 experiencing it during pregnancy. Typically, it occurs in the second third of pregnancy, and occasionally in the early postpartum period. Elevated blood volume, cardiac output, and blood pressure in late pregnancy are all risk factors for aortic dissection.
In addition, trauma, infection, and iatrogenic injury are also causes of aortic dissection.
The clinical manifestation of aortic dissection is chest pain, which is the most common symptom of aortic dissection, accounting for 74% to 90%.
This type of pain is often described as unbearable tearing pain, accompanied by sweating, nausea, vomiting, and fainting.
As mentioned earlier, the aorta sends out many branches during its course, providing blood to corresponding organs and tissues, mainly including branches of the coronary artery, branches of the head and arms, branches of the intercostal nerves, branches of the intestine, branches of the kidneys, and branches of the lower limbs.
When aortic dissection occurs, the blood of these branch vessels is also affected, resulting in a variety of symptoms of aortic dissection.
When aortic dissection affects the coronary arteries, symptoms of "myocardial infarction" may appear, and even the results of examination and laboratory tests fully match the manifestations of myocardial infarction, which can easily lead to misdiagnosis.
When aortic dissection affects the blood vessels in the head, symptoms such as cerebral infarction, hemiplegia, aphasia, blindness, etc. are also common initial symptoms of aortic dissection.
When intercostal nerves and blood vessels are involved, there is a risk of paraplegia; When the intestinal blood vessels are affected, there may be obvious abdominal pain, rectal bleeding, etc; When the renal blood vessels are affected, there may be sudden oliguria, which may even affect subsequent treatment; When the lower limb blood vessels are affected, there may be symptoms of limb pain and weakness.
Prevention of aortic dissection
Prevention of aortic dissection can be divided into three levels.
1、 Control of high risk factors
The key point is to control hypertension, especially for people who are difficult to control ideal hypertension, quit smoking, control atherosclerosis high risk factors such as hyperlipidemia and diabetes.
2、 Early detection of congenital diseases
Congenital diseases often have characteristic manifestations, such as Marfan syndrome. People with a family history, particularly thin and elongated body types, and spider fingers need to be vigilant.
3、 Popularize the common knowledge of aortic dissection
Understand the dangers of this disease, and pay enough attention to the chest, chest, and back that cannot be relieved. When calling for emergency medical help, try to go to an experienced medical unit to win valuable time for treatment, because time is life. Try to avoid sudden death during transportation and waiting for surgery.
The treatment of aortic dissection
For aortic dissection, a disease with an hourly mortality rate, timely and effective treatment is the key to saving life!
During the diagnosis and treatment process, using CT scanners with 64 or more rows for CTA examination of the entire aorta and its primary branches is the preferred diagnostic method for aortic dissection. For situations where other symptoms appear, examinations such as echocardiography and vascular ultrasound can also provide effective information for evaluating the severity of the condition.
Once diagnosed with aortic dissection, the initial treatment principles are effective analgesia, control of heart rate and blood pressure. On the one hand, it is necessary to reduce the impact force of blood on the aortic wall, and on the other hand, it is necessary to reduce the number of impacts in order to effectively reduce the risk of aortic rupture.
Surgical treatment should be considered for type A aortic dissection involving the ascending aorta. Through surgical treatment, the rupture of aortic dissection can be fully eliminated, the damaged aorta can be replaced with artificial blood vessels, the damaged branch blood vessels can be reconstructed, and the true lumen of the aortic blood vessels can be fully dilated with covered stents to improve the blood supply to organ tissues.
For some B-type dissections that do not involve the ascending aorta, endovascular stents can also be used to reduce the risk of dissection rupture with less trauma.