What is aortic coarctation?
The aorta has three structural layers, called the intima, mesentery and epia. The so-called aortic coarctation occurs when the endothelium and mesothelium of the aorta rupture for various reasons, and arterial blood flow enters the middle of the aortic wall through this fissure, 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 are the characteristics of aortic coarctation.
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.
What are the risks of aortic coarctation?
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 coarcted aneurysm. As the diameter of the aneurysm increases, the patient’s entrapped aneurysm will eventually rupture leading to death.
What is the incidence of aortic coarctation?
The literature reports the incidence of aortic coarctation to be 50-100 per 100,000 people per year. And bulk autopsy reports suggest an incidence rate of 0.2 to 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 the patients with clamps is younger, generally around 50 years old.
What are the clinical manifestations of aortic coarctation?
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. Firstly, most patients with this disease have the basis of hypertension, and secondly, the formation of the entrapment will in turn further increase the blood pressure.
3. Clamp rupture: Hemorrhage caused by rupture is the main cause of death from clamping. About half of the patients die due to rupture in the acute phase of the disease, while those who survive from 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, besides 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.Organ and limb ischemic manifestations: In addition to rupture, another hazard of entrapment is to affect the blood supply of aortic branch vessels, including brain, heart, intestine, kidney, 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 extremities.
What is the clinical staging of aortic coarctation?
Aortic coarctation can be staged according to the time of occurrence. It is generally considered that clips less than 14 days old are called acute clips, and clips greater than 14 days old 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. This generally refers to the period of 14 days to two months after entrapment
How is aortic coarctation staged?
The disease is classified according to the site of the entrapment and the characteristics of the clinical management into Standford type A, where the entrapment involves the ascending aorta, and Standford type B, where the entrapment involves only the descending aorta.
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 bulbs and widened mediastinum, but chest radiographs cannot be used as a confirmatory diagnostic tool for 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 and expensive test, DSA techniques are more often used in endoluminal treatment techniques for aortic coarctation.
What are the treatment options for aortic coarctation?
The surgical treatment of aortic coarctation includes both traditional surgical treatment and endoluminal treatment.
What is the traditional surgical approach to aortic coarctation?
The traditional treatment is artificial vessel replacement, specifically, the patient is put under general anesthesia, the chest is opened (in some patients, the abdomen is also opened), extracorporeal circulation is established, the aneurysm is dissected out, the diseased and broken aortic segment is removed, and the artificial vessel is anastomosed with the relatively normal aorta at each end of the aneurysm to restore blood flow to the aorta, and sometimes multiple branch vessels are reconstructed. 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, and pulmonary and renal decompensation, making the surgery more dangerous, and many patients lose the opportunity to be treated because they cannot tolerate the surgery.
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 the blood supply to the organs. Instead of opening the chest or abdomen, the procedure requires only a small incision 3-5 cm long at the root of the thigh. Under X-ray fluoroscopic surveillance, a delivery device containing a graft (stent-type vessel) is introduced through the femoral artery, and after reaching the diseased aorta, the graft is released and propped open 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.
What are the advantages of endoluminal repair of aortic coarctation?
Compared to traditional open-heart and open-heart surgery, the most prominent features of endoluminal repair are its simplicity, minimal invasiveness, and proven efficacy. 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.
Will patients rest easy after successful endoluminal treatment of aortic coarctation?
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.
What do patients need to pay attention to in their life after aortic coarctation?
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 blood pressure fluctuations. Heart rate should be controlled within 80 beats/min.
2.Improve lifestyle, moderate exercise, avoid strenuous exercise, low salt and low fat light diet, avoid emotional excitement, and actively control blood lipids and blood sugar.
3, 3 months, 6 months, 9 months, 1 year after surgery to regularly seek professional doctors to do vascular ultrasound or CTA examination.