If you ask about the ranking of surgical diseases, they must be "on the list"—— Aortic dissection 。 It goes without saying that the aorta is the main artery of the systemic circulation and the great center of the human body! The following 6 questions and 6 answers reveal the secret of this "ferocious leader"!
Author: Zhao Keqiang, Department of Vascular Surgery, Changgeng Hospital, Tsinghua University, Beijing 1. What is aortic dissection?
The aortic wall has or does not have its own pathological changes, and a series of external factors（ hypertension , trauma, etc.), and blood enters the middle layer of the aortic wall from the intimal tear, causing the middle layer of the aorta to separate along the long axis, thus making the aortic lumen present a pathological state of true and false lumens.
2. How dangerous is aortic dissection?
Acute dissection aneurysm % of patients may die suddenly or within hours or days. Among the patients with dissecting aneurysm in the meta literature, 50% died within 48 hours, and the risk of death per hour accounted for 1%. 70% died within one week and 90% within three months. The main cause of early death is massive hemorrhage caused by tumor rupture shock Death or blockage of blood supply arteries of important organs, such as coronary artery, carotid artery or visceral artery.
3. Feel the danger again: What are the main clinical symptoms of aortic dissection?
In the actual situation, it can be shown in different situations, mainly including the following:
1) The typical patients with acute aortic dissection often show sudden, severe, chest back, tearing pain. Serious can occur Heart failure 、 syncope , even sudden death; Most patients were accompanied by uncontrollable hypertension;
2) Aortic branch artery occlusion can lead to corresponding ischemic symptoms of brain, limbs, kidneys and abdominal organs, such as cerebral infarction, oliguria, abdominal pain, pale legs, weakness, piercings, and even paraplegia Etc.
3) In addition to the above main symptoms and signs, because of the wide area of aortic blood supply, the performance varies according to the cumulative range of dissection. Other situations include: peripheral arterial pulsation disappears, and vocal cord paralysis may occur when the left recurrent laryngeal nerve is compressed; Hemoptysis and hematemesis may occur when the dissection penetrates the trachea and esophagus; The dissection compresses the superior vena cava Superior vena cava syndrome ； The compressed trachea showed dyspnea; Horner syndrome occurs when cervical thoracic ganglion is compressed; Presence of compressed pulmonary artery pulmonary embolism Physical signs; Dissection involving mesentery and renal artery may cause intestinal paralysis, necrosis and renal infarction. Pleural effusion It is also a common sign of aortic dissection, mostly on the left side.
4. What kind of people are prone to aortic dissection?
Aortic dissection is the result of the interaction between aortic media structure and abnormal hemodynamics. When the aortic structure is abnormal, the intima-media of the aorta is naturally prone to rupture. Common factors include: Marfan syndrome, congenital cardiovascular malformation, idiopathic degenerative changes of the aortic media atherosclerosis , aortitis, etc. We are familiar with the American women's volleyball player Heiman and the men's volleyball player Zhu Gang who fell on the sports field for these reasons.
When hemodynamics changes, it is also easy to cause arterial wall damage. The most common cause is hypertension. Almost all patients with aortic dissection have hypertension under control. In other words, the control of hypertension has a comprehensive impact on the prevention, treatment and prognosis of aortic dissection, and is the most basic and most important treatment and prevention means.
gestation It is another high risk factor, which is related to hemodynamic changes during pregnancy. 50% of the women who got sick before the age of 40 were pregnant. The ratio of male to female incidence of aortic dissection is 2-5:1; The common onset age is 45~70 years old, and the youngest patient reported at present is only 13 years old.
According to the location of intimal tear of aortic dissection and the extent of dissection, there are two main medical classification methods. The most widely used is the Type III classification proposed by Professor DeBakey and others in 1965:
Type I: aortic dissection extends from ascending aorta to descending aorta and even to abdominal aorta;
Type II: The scope of aortic dissection was limited to the ascending aorta;
Type III: aortic dissection involving the descending aorta, and type IIIA if the descending aorta is not involved; Type Ⅲ B was found when the abdominal aorta was involved downward.
In 1970, Professor Daily of Stanford University and others proposed another classification method mainly based on the location of proximal intimal tears: Stanford A: equivalent to DeBakey I and II; Stanford B type: equivalent to DeBakey III type.
Figure 1: Type A aortic dissection involving the whole aorta
Figure 2: Type B dissection involves far from the descending aorta 5. How to diagnose aortic dissection?
The main auxiliary examinations for the diagnosis of aortic dissection are: CT angiography (CTA), magnetic resonance angiography (MRA) or direct digital subtraction angiography (DSA).
Before treatment
After stent implantation 6. How to treat aortic dissection?
1) Conservative treatment
For patients with acute dissection, no matter what treatment means we need to take further, we should first take corresponding conservative treatment: control blood pressure and pain. It is usually necessary to use powerful drugs, such as sodium nitroprusside for lowering blood pressure, morphine for analgesia, etc. For patients in critical condition, emergency tracheal intubation and ventilator assisted breathing are often required for emergency rescue surgery, but it also means high risk and mortality.
2) Surgical and interventional treatment
After the patient's condition is properly stabilized, the choice of treatment mode depends mainly on the type of dissection. As far as the current treatment status is concerned, minimally invasive endovascular treatment is the main treatment for Stanford B aortic dissection. The basis of treatment includes the following conditions, or surgical indications: the dissection continues to expand, which is characterized by rapid increase in the diameter and scope of aortic dissection, chest bleeding, and uncontrollable pain; Or the main branch of aorta, such as superior mesenteric artery and renal artery ischemia.
The traditional minimally invasive endovascular repair of aortic dissection requires at least 1.5 cm of anchoring area on the aorta to prevent incomplete proximal closure and internal leakage. However, with the improvement of endovascular repair equipment and the progress of endovascular repair technology, this indication has been expanded, and Stanford B aortic dissection within 1.5 cm from the main fissure to the left subclavian artery opening can be treated by hybrid surgery or various endovascular repair techniques (chimney, windowing, modular branch stent).
For endovascular repair of Stanford A type aortic dissection with a tear in the ascending aorta, some scholars placed covered stents in the ascending aorta to isolate the proximal dissection tear, but this operation requires specific anatomical conditions. Sun's operation is still the main treatment for type A aortic dissection at present.
