I. What is aortic dissection?
Aortic dissection (AD), known as the “bomb” in the human body, is a relatively rare but extremely critical type of cardiovascular disease with a high mortality rate. Aortic dissection is the formation of a wall dissection in the aorta, which used to be called dissection aortic aneurysm. It refers to the rupture of the intima of the aortic wall caused by various reasons, and the blood flow enters the aortic wall, resulting in the delamination of the vessel wall and the formation of a “double-lumen aorta” by the separation of the peeled intima.
II. What are the characteristics of AD?
AD is a very dangerous disease, characterized by rapid onset and high mortality rate. If the patient is not accurately diagnosed and treated in time, the mortality rate increases by 1% per hour within 48 hours of onset, and the mortality rate can reach 70% in one week and 90% in three months.
The current treatment options for AD include conservative treatment, surgery, and stent placement. The mortality rates of different treatment options are shown in Table 1.
III. What are the causes of AD?
1) 50% to 80% of patients with hypertension, often after the age of 40;
2) Cystic degeneration of the middle layer of the aorta due to genetic defects in connective tissue, such as Marfon syndrome (proximal entrapment) and Ehlers-Danlos syndrome;
3) Certain congenital heart diseases: e.g. aortic constriction, diastolic aortic valve, aortic hypoplasia, etc;
4) Inflammatory diseases: such as syphilitic aortitis, giant cell aortitis, granulomatous vasculitis, etc;
5) Thoracic injury, interventional examinations and treatment with cannulation injury, etc.
IV. What is the AD staging?
The De Bakey typing is commonly used in clinical practice. (See Figure 2 for details)
Type I: The lesion starts in the ascending aorta and extends through the aortic arch to the descending aorta;
Type II: confined to the ascending aorta;
Type III: The lesion starts from the descending aorta and extends distally, and may also extend proximally to the aortic arch and ascending aorta.
V. Clinical manifestations of AD
1.The most common manifestations of AD
One of the most common manifestations is pain, which is mainly seen in 90% of AD patients.
Features include.
1) Sudden onset, with a peak at the beginning;
2) Severe, the patient tosses and turns, the pain is not completely relieved by conventional doses of morphine and other analgesics;
3) Persistent: can last for several days;
4) Movement: often starts from the anterior chest near the sternum, and the pain site moves as the entrapment expands;
5)Accompanying symptoms: nausea, vomiting, cold sweat.
2. Performance of each system
(1) Changes in blood pressure.
1)Most of the blood pressure is elevated;
2)Some patients may have hypotension, which may be related to pericardial tamponade;
3) Blood pressure of both upper limbs is inconsistent.
(2) Neurological.
1) Syncope: proximal entrapment is common, caused by obstruction of blood supply vessels to the brain or pericardial tamponade;
2) Involvement of cerebral or spinal arteries or hematoma compressing vascular nerves can cause various local symptoms of the nervous system, such as cerebrovascular accident, blindness, hoarseness, Horner syndrome, ischemic peripheral neuropathy, ischemic lower limb light paralysis, etc.
(3) Digestive system: When the entrapment affects the blood supply of abdominal organs, it may cause necrosis of the corresponding organs, abdominal pain and blood in stool; when the entrapment compresses the esophagus, it may cause difficulty in swallowing and vomiting blood when it breaks into the esophagus.
(4) Respiratory system: the clot may cause chest pain, dyspnea, cough and shock when the clot breaks into the chest cavity and causes blood accumulation in the chest cavity.
(5) Urinary system: involvement of the renal artery may cause lumbago, hematuria, severe hypertension and acute renal failure.