Aortic coarctation, also known as aortic coarctation aneurysm, is a condition in which the endothelium of the aortic wall ruptures due to internal or external forces, and blood seeps through the endothelial rupture into the middle layer of the aortic wall and forms a hematoma that extends and peels away, resulting in severe pain primarily. It is a very critical cardiovascular emergency. Feng Baolin, Department of Cardiovascular Medicine, No.2 People’s Hospital of Neihuang, Henan Province, China
1 Etiology and prevalent sites
The etiology of this disease is still not well understood. Hypertension; cystic degeneration of the middle layer of the aorta; congenital cardiovascular disease; hereditary cardiovascular disease; local inflammation, abscess, trauma, medical causes; atherosclerosis, etc. can all cause or trigger the occurrence of this disease. Among them, the degeneration of the middle layer of the aorta is an important basis for aortic coarctation separation. Hypertension is an important contributing factor to aortic coarctation separation. The basic pathological features of the disease are focal necrosis and hemorrhage in the middle layer of the aorta, gradual expansion of the hemorrhagic foci to form a hematoma, and tearing toward the middle layer to form a coarctation, even leading to hematoma rupture. Aortic dissection most commonly occurs in the ascending aorta, followed by the thoracic and abdominal descending aorta. The disease may extend distally, invading the innominate, common carotid, subclavian, and coronary arteries as well as the intercostal, mesenteric, renal, and bilateral iliac arteries, forming extensive arterial entrapment separations.
2 Clinical symptoms and staging
Once aortic coarctation occurs, 85%-90% of patients have sudden onset of severe and persistent pain, mostly in the anterior chest near the sternum, back, posterior scapular region, which may radiate to the head and neck, throat, jaw or teeth, abdomen or lower extremities, laceration-like or knife-like in nature, severe and unbearable, accompanied by a sense of suffocation, near death, fear, and lasting for a long time, even until death In addition In addition, aortic coarctation can also appear as a hematoma compressing surrounding tissues or invading aortic branches, causing signs and symptoms of organ or tissue damage in the corresponding area. Cardiovascular manifestations, respiratory symptoms, gastrointestinal manifestations, urinary symptoms, and neurological dysfunction may occur.
Aortic coarctation is commonly clinically classified as de BaKey: type I for full aortic separation; type II for ascending aortic separation; and type III for descending aortic separation. New classification methods are still available.
3 Clinical diagnosis and differential diagnosis
Once aortic coarctation is suspected clinically, conventional X-rays are not diagnostic, meaning that most patients with aortic coarctation have normal conventional chest radiographs. In a large survey of international international aortic coarctation (IRAD), the first diagnostic steps were transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in 33%, CT in 61%, magnetic resonance imaging (MRI) in 2%, and angiography in 4%. If an endothelial tear of the flap dividing the aorta into two lumens is found to be the basis for the diagnosis of aortic coarctation. Changes in the endothelial flap, calcification or separation of the endothelial layer are also considered signs of aortic coarctation if the false lumen is completely obstructed by a thrombus.
Separation of aortic coarctation needs to be differentiated from the following diseases in the diagnostic process: non-S-T segment elevation acute coronary syndrome; aortic regurgitation; aortic aneurysm; skeletal muscle pain; mediastinal tumor; pericarditis; pleurisy; pulmonary embolism; cholecystitis; cerebrovascular accident; surgical emergency abdomen, etc.
4 Internal treatment of aortic coarctation
Once aortic coarctation is diagnosed, most of them need interventional and surgical treatment, but the conditions of interventional and surgical treatment are not available at the primary level, so it is very important to treat the aortic coarctation as an emergency measure. In addition, if there are indications for medical treatment, medical treatment can also be performed: if the entrapment starts in the descending aorta and is located distal to the left subclavian artery; to reduce the risk of surgery, medical treatment can be performed first; if the blood in the pseudolumen of the entrapment is coagulated and relatively stable; if the onset of chronic entrapment is more than 2 weeks; for those who are not suitable for surgery, such as advanced age, cancer, or multiple organ failure, medical drug treatment can be performed.
1) Immediately admit to the monitoring ward and closely monitor blood pressure, heart rhythm, water intake and output, and mental status.
2） Strict bed rest and oxygen inhalation.
3） Sedation and pain relief. Commonly used morphine 5-10mg intravenously, Valium 10-20mg intravenously.
4） Patients with decreased blood pressure can be infused intravenously with whole blood, plasma or plasma substitutes, and if necessary, apply vasoactive drugs such as m-hydroxylamine and dopamine. If the blood pressure level is low and the patient can tolerate it, it is not necessary to emphasize elevated blood pressure to avoid aggravating the condition.
5) For those with respiratory distress, take a 30-degree recumbent position.
6) High blood pressure is more common in patients with aortic coarctation and requires active treatment, which is also the focus of treatment for this disease. The clinical use of nitroprusside intravenous drip, starting from 10-25ug/min, later adjust the drip rate according to the blood pressure, the maximum amount available 150-200ug/min, so that the systolic blood pressure down to 100-120mmHg. can also be used with ACEI, CCB drugs. The dose rate can be adjusted according to the blood pressure. If possible, the cause of hypertension can be further investigated and thorough treatment can be sought.
7) β-blocker application. β-blocker can reduce the left ventricular ejection velocity, which can effectively stop the progress of clamping separation, and clinically control the heart rate to 60-70 times/min. Propranolol, metoprolol, atenolol and other drugs are commonly used clinically.
5 Clinical experience
1) Pain reduction or disappearance after blood pressure drop in patients with aortic coarctation is regarded as an indication that the treatment is effective and the coarctation separation stops expanding.
(2) The change of blood pressure in patients with aortic coarctation needs to be differentiated from shock.
(3) The differential diagnosis should be grasped at the early stage of painful aortic coarctation separation to avoid misuse of anticoagulation and thrombolytic therapy.
(4) When using nitroprusside c, attention should be paid to avoid light and change the dropper bottle in 4-6 hours. Pay attention to cyanide poisoning in long-term use.
5) Interventional and surgical treatment should be actively recommended along with medical treatment and to create conditions and buy time to avoid life-threatening rupture of the entrapment.