A dangerous aortic dissection

 The aorta, the largest blood vessel in the body, connects the heart to the body's circulation and is a vital conduit for life. Acute aortic syndrome is a serious cardiovascular disease that threatens human life and health. In recent years, with the popularization of multi-slice spiral CT angiography and other imaging techniques, the diagnosis rate of acute aortic syndrome has been greatly improved. At the same time, the development of surgical techniques and endovascular repair techniques has significantly reduced the incidence of mortality and complications in acute aortic syndrome surgery. Even so, acute aortic syndrome is still very difficult to operate on, and one such operation is often a great challenge for the surgeon. At the same time, the mortality rate of this type of surgery has decreased significantly, but it is still high compared to other types of heart surgery.

Existing clinical studies show that acute aortic syndrome has a sudden onset and high mortality, and the true incidence is even difficult to calculate. So how should we treat this dangerous disease?

A very serious aortic dissection

The aorta connects the heart to the vital organs in the body's systemic circulation. It starts from the heart's left ventricle and curves arcuate down the spine. Bounded by the diaphragm, the aorta is divided into the thoracic aorta and the abdominal aorta. The thoracic aorta is divided into ascending aorta, aortic arch and descending aorta. The normal aortic wall consists of three layers, namely the intima (endothelial cells and intercellular junctions), the middle membrane (elastin, collagen fibers, and smooth muscle cells), and the outer membrane (collagen fibers, nutrient vessels, and lymphatic vessels). The elastic retraction of the aorta during ventricular diastole also acts as a "secondary pump", pumping blood to the distal end and maintaining continuity of blood flow, which is of great importance.

Acute aortic syndrome consists of three types of aortic lesions, namely, aortic dissection, intramural hematoma and penetrating aortic ulcer. Aortic dissection, which we often hear about, is one of the most dangerous critical conditions for patients.

Refers to the aortic intima fracture, aortic dissection of aortic lumen of blood into the aorta from aortic intimal tear film, make the membrane separation, formed along the aorta extending along the long axis of two cavities of true and false of the aortic wall separation condition, mezzanine can be spread to the ascending aorta and aortic arch and descending aorta alone, can also be combined multiple aortic segment.

The main characteristics of aortic dissection are sudden onset and rapid progression. Most patients will have sudden severe pain in the aorta walking or mapping area during acute onset, which is persistent and unbearable.

The peak age of aortic dissection is between 50 and 70 years old, the incidence ratio of male to female is about 2.5 times 1, and the incidence is between 1/100,000 and 1/200,000 per year. Compared with coronary heart disease, valvular heart disease and other common cardiovascular diseases, its incidence is not high, but its prognosis is very poor, which is another characteristic of this disease -- poor prognosis, high mortality.

Beijing anzhen hospital affiliated to the capital university of medical sciences, dean hong-jia zhang tells us that patients with aortic dissection with cardiac complications, such as dissection involving the aortic leaf of ring the valve leaflets or possible aortic valve closed when support is not complete, acute aortic regurgitation can cause heart failure, and if the important branch of lesions involving the aortic vascular, May also lead to other important organs of the human body ischemia or poor perfusion. These complications greatly reduce the patient's chance of survival, which is why the disease has a very poor prognosis and high mortality. Clinical statistics show that when aortic dissection occurs, the intima and media of blood vessels are torn, and the mortality within 48 hours of the onset is up to 50%! And the vast majority of patients died of acute cardiac tamponade, malignant arrhythmia and other high-risk complications.

Because of this, early diagnosis and treatment of aortic dissection is very necessary. Zhang Hong told us that aortic dissection is mainly treated by surgery. According to surgical requirements, aortic dissection can be divided into type A and TYPE B, and the rupture located in the ascending aorta is type A, which is suitable for emergency surgery. For type B dissection lesions confined to the abdominal aorta or iliac artery, medical treatment may be performed first, followed by open surgery or endovascular treatment. Especially for type A aortic dissection, surgery is often necessary. Zhang Hong stressed to us that without surgical intervention, the death rate of Type A aortic dissection would increase by 1% every hour, and almost all patients would die within A year.

Aortic surgery: the crown jewel of cardiac surgery

Operating on a diseased aorta in the human body is like dancing ballet on a glass plate. It is the long time, high difficulty, high complexity and low fault tolerance of aortic surgery that makes it known as "the crown jewel of cardiac surgery."

In the surgical treatment of acute aortic syndrome, the ruptured aortic vessel is usually replaced by an artificial vessel with a normal structure. Therefore, vessel replacement should be carried out from the aortic root to the aortic dissection. Its surgical operations include coronary artery bypass, aortic valve replacement, replacement of the entire aortic arch, anastomosis of the brachiocephal trunk and other cardiac surgical techniques, and deep hypothermia extracorporeal circulation during surgery, which can be said to almost focus on all the high-end techniques of cardiac surgery, the difficulty of the operation is self-evident.

The aorta is the largest blood vessel in the human body, ranging in diameter from 2 to 2.5 centimeters. About half of patients die outside the hospital when they rupture an aortic dissection without a chance to reach the hospital.

Patients with acute aortic syndrome often have an acute onset, and the operation is difficult and complex. Therefore, the operation time is longer, generally taking 8 to 10 hours. Patients are often hospitalized in the evening, and can only go out of the operating room at dawn, which can be described as a night battle and bitter battle. In the past, due to the problems of surgical techniques and materials, the amount of blood loss in patients with acute aortic syndrome was often very large. Even if the patient is found in time and the operation is successful, the patient may still die from complications such as massive bleeding, malignant arrhythmia, cardiac decompensation, multiple organ failure, cardiac tamper, and dissection tear again. Therefore, the surgeon is often under great pressure, which can be described as a death battle. At present, Beijing Anzhen Hospital is the hospital with the largest volume of aortic dissection surgeries in China. The professional team of Anzhen Hospital performs more than 1,000 aortic surgeries every year, and has also formulated the Chinese Expert Consensus on the Diagnosis and Treatment Norms of Acute Aortic Syndrome (2021 edition).

Three factors that affect the success of surgery

Of course, acute onset, rapid progress, complex condition and difficult operation are the main reasons for the poor prognosis of acute aortic syndrome, but there are still three "stumbling blocks" affecting the success of operation.

Stumbling block 1: Patients do things at home that they shouldn't

Ignore abdominal pain: the first symptom of many people when they come on is abdominal pain, but most of them will be mistaken for gastroenteritis so as to affect medical treatment and treatment. Experts tell us that aortic dissection can start from the ascending aorta, and can always involve the abdominal aorta or even the arteries of the lower limbs. If the blood vessels in the abdominal cavity are involved, abdominal pain, vomiting, blood in the stool and other symptoms will be caused.

If the dissection involves the renal artery, it will cause symptoms such as oliguria and back pain. Therefore, aortic dissection is very easy to be misdiagnosed. We must pay attention to these symptoms.

Repeated use of nitroglycerin: Nitroglycerin is a common treatment for coronary heart disease, but it does not respond to aortic dissection. General nitroglycerin effect in 3 ~ 5 minutes, if the symptoms of relief will prove that coronary heart disease, if taking 1 ~ 2 times found no effect, should immediately go to a specialist hospital, do not take nitroglycerin repeatedly, to avoid missing the best treatment opportunity.

Eat or drink water: In the acute phase of aortic dissection, the aortic wall is as thin as paper, though not as thin as a wing, due to the tearing of the blood vessel wall. A slight cough or choking may become the "last straw" to cause aortic rupture. Therefore, it is not recommended to eat or drink water in the early stage of aortic dissection to avoid choking and reduce the risk of anesthesia during emergency surgery.

Stumbling block 2: "urgent diagnosis" misjudgment

"Urgent care" refers to an important function of the emergency department, which is to diagnose life-threatening critical conditions in the first place, followed by seamless specialist care. So "urgent diagnosis" is an important prerequisite for specialist rescue.

Aortic dissection, pulmonary embolism and acute myocardial infarction are three very common vascular diseases, and all of them are critical and severe diseases that need to be diagnosed at the first time. However, the signs of these three diseases are similar, and not only patients will be confused, but also doctors may misjudge. Misdiagnosis of emergency will greatly affect the success rate of operation.

Stumbling block 3: Confusion in image examination

Due to intimal tear, aortic dissection in general from the image you can see a true cavity and a false lumen, but when patients with heart rate too fast or machine debugging problems, also shows the aortic artifacts in the images, which tend to let the doctor is difficult to determine whether the aortic dissection, real diagnosis and follow-up of the surgical treatment to bring huge difficulties.

Learn to distinguish the pain of aortic dissection

Aortic dissection, coronary heart disease and pulmonary embolism are all critical and acute cardiovascular diseases with similar clinical manifestations. Patients often complain of chest pain when seeking medical treatment. Therefore, the differential diagnosis of these three diseases is particularly important. This is not only for doctors, but also for patients. All patients with cardiovascular disease and those at high risk should learn to distinguish what kind of risk they are at, so that doctors can better judge the condition of the disease.

1. Pain perception and relief time are different

Aortic dissection: Laceration pain

The pain of aortic dissection is completely different from the pain of coronary heart disease or pulmonary embolism. It is a kind of tearing pain, severe degree, and even shock due to the pain. In addition, the pain caused by aortic dissection will travel along with the site of dissection tear, such as chest pain at the beginning, and gradually extend to back, abdomen, waist and even lower limbs as the scope of intima tear expands.

Coronary heart disease: crush feeling

Chest tightness and chest pain caused by coronary heart disease are often characterized by a crushing sensation in the chest area. If the pain persists for half an hour, call 120 immediately.

Pulmonary embolism: Pain affected by breathing

Pulmonary embolism is the systemic circulation of various embolic loss caused by blocking the pulmonary artery and its branches in pulmonary disorders, in addition to the sudden chest pain, patients also tend to sudden unexplained collapse, pale, sweating, dyspnea, cough and other symptoms, and can appear extremely anxious, lack of symptoms such as fatigue, nausea, convulsions and coma.

Chest pain caused by pulmonary embolism is caused by ischemia of distal blood vessels and inflammation involving parietal pleura. It is a very severe pain, and pain will be affected by respiratory movement. To avoid injury and pain is the human body's instinct, as well as a self-protection mechanism. To avoid pain, patients with pulmonary embolism will unconsciously reduce the respiratory motion range of the affected side of the lung or chest cavity, so patients with pulmonary embolism will unconsciously experience partial respiratory depression, while the pain of aortic dissection is not related to breathing.

2. Blood pressure changes differently

The progression of arterial dissection often involves the vessels supplying the limbs, such as the femoral and radial arteries, resulting in impalpability of the dorsalis pedis or hypotension, whereas coronary heart disease and pulmonary embolism do not. Therefore, palpation of dorsalis pedis artery and measurement of blood pressure are one of the ways to distinguish aortic dissection.

Scientific intervention, prevention first

Since the treatment of aortic dissection is extremely difficult and the prognosis is mostly poor, it is particularly important to prevent aortic dissection before the disease occurs.

This disease occurs in patients with high blood pressure, so controlling blood pressure is very important. According to clinical statistics, the incidence of aortic dissection due to hypertension and atherosclerosis accounts for 70% to 80% of the total incidence. This is because hypertension can make the arterial wall in a long-term stress state, and elastic fibers often undergo cystic degeneration or necrosis, which can eventually lead to the formation of dissection. In addition, aortic degenerative change is the basis for the development of acute aortic syndrome occurring conditions, and high blood pressure leads to greater blood flow shear stress and pressure vessel wall, composed of both mechanical stress will further aggravate the aortic blood vessel walls before and after the degeneration of structural damage risk, create conditions for the happening of the sandwich.

Therefore, experts suggest that people over the age of 50 should regularly monitor their blood pressure, which can be measured at home by themselves. Blood pressure can be measured in the morning and evening every day. Each measurement should be taken 2 to 3 times, with an interval of 1 minute, after sitting for 5 minutes. Any increase or fluctuation in blood pressure should be treated immediately to nip the risk of acute aortic syndrome in the bud.

【 Experts warn 】 Living a regular life, not staying up late, not drinking too much, and getting six to eight hours of sleep a day are important to protect the circulatory system.