1.What is aortic coarctation?
The aorta has three structural layers, called the intima, mesentery and epia. The so-called aortic coarctation is caused by rupture of the endothelium and mesothelium of the aorta for various reasons, and arterial blood flow enters the middle of the aortic wall through this rupture, thus causing a separation of the aortic wall. The blood flow extends distally and proximally along the aortic wall and can involve the entire length of the thoracic aorta and even the abdominal aorta and its branches. Therefore, aortic coarctation is so devastating that it is called “catastrophic disease” of the aorta. If the original lumen of the artery is called the true lumen, the lumen formed by the separation of the middle membrane is the false lumen. The true lumen and the false lumen constitute the characteristics of aortic coarctation.
2.What are the causes of aortic coarctation?
The causes of aortic coarctation are complex. The common ones are: hypertension, atherosclerosis, trauma, medical injury, pregnancy, inflammation, and genetic factors (Marfan’s syndrome). Among them, hypertension is the most important.
3.What is the danger of aortic coarctation to human body?
Aortic coarctation is rapid and devastating. In the acute stage, it can cause aortic rupture and ischemia of organs and limbs, leading to death, while in the chronic stage, aortic coarctation can gradually expand to form a coarctation aneurysm. As the diameter of the aneurysm increases, the patient’s entrapped aneurysm will eventually rupture leading to death.
4. What is the incidence of aortic coarctation?
The incidence of aortic coarctation is reported in the literature to be 50-100 per 100,000 people per year. And the bulk autopsy report suggests the incidence rate is 0.2~0.8%. There are few studies on the epidemiology of aortic coarctation in China, but clinical experience suggests a higher incidence of aortic coarctation in mainland China than in Western countries. This may be related to the high prevalence of hypertension and the fact that hypertension is not well controlled in China. In the West, aortic coarctation occurs mostly in people over 60 years of age, with an average age of 69 years for men and 76 years for women, and is two to three times higher in men than in women. In China, the age of patients with coarctation is relatively young, generally around 50 years old.
5.What kind of clinical manifestations does aortic coarctation have?
(1) Chest pain: 90% of patients will have sudden onset of severe pain in the chest, back or abdomen at the onset of aortic coarctation. The pain often appears when making some sudden movements, such as lifting heavy objects, playing basketball, or even yawning, coughing, or straining to defecate. The pain is cut or torn, intense and radiates distally from behind the sternum or back of the chest. The site of pain onset often suggests the site of the entrapment rupture. Patients are often irritable, sweating profusely, have a sense of near death, and may faint from the pain. In patients who survive the acute phase, the chest pain gradually disappears or turns to vague pain.
(2) Hypertension: It is the most common sign in patients with aortic coarctation. First, most patients with this disease have an underlying hypertension, and second, the formation of the entrapment will in turn further increase blood pressure.
(3) Sandwich rupture: Hemorrhage caused by rupture is the main cause of death from sandwich. About half of the patients die from rupture during the acute phase of the disease, while those who survive the acute phase and enter the chronic phase will gradually form an intercalated aneurysm, and eventually the intercalated aneurysm will also rupture. When rupture occurs, in addition to the above-mentioned severe chest pain, there are also manifestations of hemorrhagic shock such as blood pressure drop, pale face, cold sweat, cyanosis, and some other special manifestations: rupture into the esophagus as vomiting blood, rupture into the trachea as hemoptysis, rupture into the pericardium as pericardial tamponade, rupture into the chest as dyspnea, etc.
(4) Ischemic manifestations of organs and limbs: In addition to rupture, another danger of entrapment is to affect the blood supply of aortic branch vessels, including the brain, heart, intestines, kidneys, lower limbs, etc., which can cause ischemia, dysfunction and even functional failure of these organs. The common ones are cerebral infarction, heart attack, abdominal pain, jaundice, blood in stool, oliguria or anuria and severe ischemia of lower limbs.
6.What is the clinical stage of aortic coarctation?
Aortic coarctation can be staged according to the time of occurrence. It is generally considered that clips of less than 14 days are called acute clips, and clips of more than 14 days are called chronic clips. Some scholars have proposed the concept of subacute entrapment, mainly considering that the entrapment lesions in this period are characterized by vascular fibrosis and inflammatory response. It generally refers to the period of 14 days to two months after the entrapment.
6.How is aortic coarctation staged?
The disease can be divided into Standford type A, where the entrapment involves the ascending aorta, and Standford type B, where the entrapment involves only the descending aorta, depending on the location of the entrapment and the characteristics of clinical treatment.
7.How is aortic coarctation diagnosed?
A variety of special tests can be used to diagnose aortic coarctation. For example, chest radiographs can show enlarged aortic bulb and widened mediastinum, but chest radiographs cannot be used as a means to confirm the diagnosis of entrapment. Enhanced CT is commonly used to diagnose aortic coarctation. It has the characteristics of safety, simplicity, accuracy and economy. Therefore, enhanced CT is of great value in both the diagnosis and preoperative evaluation of aortic coarctation. Magnetic resonance angiography (MRA) is also a good method to diagnose aortic coarctation, but MRA images are slightly blurred, especially in measuring the intravascular diameter, which is not accurate enough. Transesophageal ultrasound (TEE) is a good method to diagnose aortic coarctation safely, noninvasively, with high sensitivity and specificity, and can make a diagnosis of aortic coarctation very accurately and quickly. The disadvantage is that the operation cannot be successfully completed in patients with unstable conditions in the emergency department, and there are limitations in the observation of the arch and its branch vessels due to the interference of the trachea. Also, TEE cannot observe abdominal aortic entrapment and fissures. Digital subtraction angiography (DSA) is an effective means of diagnosing aortic coarctation, but because it is an invasive test and expensive, DSA technology is more often used in endoluminal treatment techniques for aortic coarctation.
8.What are the treatment methods for aortic coarctation?
The surgical treatment of aortic coarctation includes both traditional surgical treatment and endoluminal treatment.
9.What is the traditional surgical method for aortic coarctation?
The traditional treatment method is to perform artificial vessel replacement, specifically, the patient is put under general anesthesia, open the chest (some patients also have to open the abdomen at the same time), establish extracorporeal circulation, dissect out the entrapped aneurysm, remove the diseased and broken aortic segment, and then use artificial vessels to anastomose with the relatively normal aorta at both ends of the aneurysm to restore blood flow to the aorta, and sometimes it is necessary to reconstruct multiple branch vessels. Depending on the degree of difficulty, the operation can take anywhere from 4 hours to more than 10 hours, with significant bleeding and transfusion. Because of the complexity of the operation, the long duration of arterial blockade, and the huge trauma, it has a direct impact on the patient’s heart, lungs, brain, kidneys, and other important organs. The postoperative period is prone to a variety of complications such as heart attack, brain attack, respiratory failure, and kidney failure. More unfortunately, aortic coarctation aneurysms usually occur in the middle-aged and elderly population, and most of them coexist with different diseases such as hypertension, coronary heart disease, diabetes mellitus, pulmonary and renal decompensation, making the surgery more dangerous, and many patients lose the opportunity to be treated because they cannot tolerate the surgery.
10.What is the principle of endoluminal treatment of aortic coarctation?
The purpose of endoluminal treatment of aortic coarctation is to prevent rupture of the aneurysm and to improve blood supply to the organs. The procedure does not require opening the chest or abdomen, but only a small incision 3-5cm long at the root of the thigh. Under X-ray fluoroscopic surveillance, a delivery device with a graft (stent-type vessel) is introduced through the femoral artery, and after reaching the diseased aorta, the graft is released and propped up and fixed in the aortic wall at both ends of the fissure, thus closing the fissure and avoiding the continuous impact of high-speed blood flow into the false lumen.
11.What are the advantages of endoluminal repair of aortic coarctation?
Compared with traditional open-heart and open-abdomen surgery, the most prominent features of endoluminal repair are simple, minimally invasive and effective. The patient recovers quickly after surgery because the treatment is less invasive, the operation time is shorter, and the amount of blood transfusion is less. Patients can usually eat and drink normally and get out of bed 24 hours after surgery. These features provide treatment opportunities for many elderly and frail patients with multiple coexisting diseases that cannot tolerate traditional surgery. Therefore, endoluminal repair has been called a revolution in the history of aortic coarctation treatment.
12.After successful endoluminal treatment of aortic coarctation, will the patient rest easy?
The rupture in aortic coarctation is often multiple, with the first rupture usually in the isthmus of the descending aorta, with multiple ruptures distal to it, and often next to important visceral arteries. Endoluminal treatment is to cover the first breach with a stent-type artificial vessel to prevent blood from continuing to enter the false lumen and to reduce the pressure inside the false lumen so that a thrombus can form in the false lumen with a view to achieving healing of the false lumen, but sometimes blood still flows into the false lumen from the distal breach, and although the pressure has been greatly reduced, there is still a risk that the distal false lumen will continue to grow and lead to rupture. This is why it is critical for patients to be reviewed regularly after successful endoluminal treatment of aortic coarctation. If the distal entrapment is still present and gradually increasing in size. Surgical treatment is still needed.
13.What do patients with aortic coarctation need to pay attention to in their life after surgery?
(1) Control blood pressure and heart rate. Take oral antihypertensive drugs regularly as prescribed by the doctor to control blood pressure within the normal range (systolic blood pressure not higher than 140 mmHg, diastolic blood pressure not higher than 90 mmHg), especially to avoid fluctuations in blood pressure. The heart rate should be controlled within 80 beats per minute.
(2) Improve lifestyle, moderate exercise, avoid strenuous exercise, low-salt, low-fat and light diet, avoid emotional excitement, and actively control blood lipids and blood sugar.
(3) Regular vascular ultrasound or CTA should be done by professional doctors at 3 months, 6 months, 9 months and 1 year after surgery.