Life example Shanghai Changhai Hospital Vascular Surgery Department Lu Qing Sheng
Mr. Zhang, just over 40 years old, had suffered from hypertension for more than 10 years and was recently promoted to the director of the company, and a series of days of pushing and changing glasses made Mr. Zhang feel exhausted. One morning, Mr. Zhang suddenly experienced severe chest pain while brushing his teeth, and his whole body broke out in cold sweat, covering his chest and collapsed to the ground. Seeing this, his family rushed to call the emergency number and sent Mr. Zhang to the hospital. After examination, the emergency doctor suspected that Mr. Zhang had an aortic coarctation and immediately arranged for the staff to send Mr. Zhang for an emergency CT examination. Sure enough, the CT test results confirmed the doctor’s prediction. After emergency surgery, Mr. Zhang finally turned to safety.
Doctor’s words: Aortic coarctation is an extremely dangerous disease, and the patient may die suddenly at any time due to the rupture of the coarctation.
I. A rare but very dangerous disease
What is aortic coarctation? The structure of the aorta is like a “triple splint”, and the wall of the aorta consists of three membranes (Figure 6-2-1), the inner membrane, the middle membrane and the outer membrane from the inside to the outside, respectively. Under normal conditions, these three membranes are tightly bound together and do not separate from each other. However, when the blood pressure is too high, when there is trauma or when there is self-inflicted disease, the intima ruptures and blood flow rushes from the rupture into the middle layer of the aortic wall. The high velocity, high pressure blood flow acts like a sharp knife, splitting the “triple splint” down the middle and causing the middle layer of the aorta to separate. During the separation, the patient can feel severe tearing pain. The entrapment can continue down the long axis of the aorta and the pain can extend from the chest to the back, lumbar region and abdomen. A new lumen, called the “false lumen” (Figure 6-2-2), is formed within the separated middle layer, and the original aortic lumen is the “true lumen” of the clench.
Figure 6-2-1 Three-layer structure of the aortic wall
Figure 6-2-2 Schematic diagram of aortic coarctation
After the formation of aortic coarctation, the most fatal event is the rupture of the wall. As the middle membrane of the aorta is torn open, only a thin outer membrane remains in the outer wall of the false lumen. If the outer membrane cannot withstand the rushing blood flow, it will rupture, just like a river breaking its banks. Once the aorta ruptures, the patient can die within minutes.
Another danger of aortic coarctation is blockage of the true lumen. When the pressure in the false lumen exceeds that of the true lumen, the true lumen is gradually compressed. Once compressed to its flattest point, the aorta becomes blocked. As we all know, the aorta is the main channel for supplying blood to the whole body. No matter where the blockage is, it is extremely dangerous and can be fatal in serious cases or disabling in minor cases.
Second, the most easily confused with heart attack chest pain
Acute myocardial infarction and aortic coarctation are two completely different diseases, but they have extremely similar clinical symptoms, such as acute cardiac insufficiency, profuse sweating, severe chest pain, shock and so on. Because people are familiar with myocardial infarction, when severe chest pain occurs, they often think of myocardial infarction first, and even the doctor who receives the patient will often be “preoccupied” and treat it as a heart attack. We may wish to understand the differences between the two diseases from the following six aspects.
First, patients with myocardial infarction have a history of angina attacks, while patients with aortic coarctation rarely have chest pain before the onset of the disease.
Second, patients with myocardial infarction usually have hypertension before the onset of the disease, and their blood pressure decreases at the onset of the disease. In patients with aortic coarctation, blood pressure increases rather than decreases at the onset (except for complete rupture and bleeding of the vessel).
Third, patients with myocardial infarction have persistent and severe chest pain, which is gradually increasing, and the symptoms of chest pain in patients with aortic coarctation reach their peak as soon as they appear.
Fourth, the chest pain of patients with myocardial infarction is mainly in the anterior chest, while the chest pain of patients with aortic coarctation is mainly in the back of the chest.
Fifth, the chest pain in patients with heart attack is mainly boring, while the chest pain in patients with aortic coarctation is mainly tearing-like pain.
Sixth, the electrocardiogram of infarct patients has the typical manifestation of myocardial infarction, while the electrocardiogram of patients with aortic coarctation has no manifestation of infarction.
Third, the unpredictable accompanying symptoms
In addition to chest pain, patients with aortic coarctation may have other symptoms. Very few patients do not show obvious chest pain but only accompanying symptoms. Therefore, understanding the concomitant symptoms of aortic coarctation is also helpful to confirm the diagnosis.
1. Intractable hypertension
If a patient with aortic coarctation has hypertension before the onset of the disease, after the onset of the disease, due to factors such as structural changes in the aorta, pain, stress, and renal ischemia, the blood pressure will remain high, and the systolic pressure may even be as high as 200 mmHg or more, and it is often difficult for antihypertensive drugs to take effect.
2. Low back pain
The aorta runs from the chest, back, then waist and abdomen, close to the spine. Aortic entrapment can continue from top to bottom along the long axis of the aorta, so the pain will continue from the chest to the back, waist and abdomen.
3. Stroke
During the tearing process of aortic coarctation, a true and false lumen is formed. If the pressure in the false lumen is greater than the true lumen, the true lumen will be gradually compressed. Once compressed to its flattest point, the true lumen (aorta) will become blocked. If the artery supplying the brain is compressed, it can lead to ischemic cerebral infarction, or stroke.
4. Paraplegia
The blood supply to the spinal cord comes from the intercostal arteries emanating from the aorta. If the intercostal artery becomes ischemic during the formation of the entrapment, it can cause ischemia of the spinal cord, which can be severe enough to lead to paraplegia, where the patient becomes incontinent and loses motor and sensory function in both lower extremities.
5. Abdominal pain
The abdomen contains many important organs, including the gastrointestinal tract, liver, gallbladder, pancreas, spleen and kidneys. The blood supply to all of these organs comes from the aorta. If the artery supplying an organ is blocked during the development of an aortic coarctation, it can lead to ischemia of the organ. The most serious of these are intestinal ischemia and renal ischemia, which not only cause severe pain but also lead to fatal complications such as kidney failure and intestinal necrosis.
6. Lower extremity ischemia
When the arteries supplying the lower extremities are blocked, symptoms of ischemia in the corresponding lower extremities will occur, either unilaterally or bilaterally. In mild cases, symptoms such as numbness, coldness and inability to walk in the lower extremities may occur, while in severe cases, pain in the lower extremities and even necrosis of the limbs may occur.
IV. Common triggers
What are the causative factors leading to aortic coarctation? As mentioned earlier, the occurrence of aortic coarctation is mainly related to the “lack of solidity” of the vessel wall. In other words, all factors that threaten the health of blood vessels, such as smoking, hypertension, hyperglycemia, hyperlipidemia, etc., are triggers of aortic coarctation.
1. Atherosclerosis
Firstly, atherosclerotic plaques are deposited on the intima of blood vessels, and once the plaques rupture or fall off, the intima will be broken, and the high-pressure blood flow in the aorta will easily enter the vessel wall through the intima rupture and form a sandwich. Secondly, after endothelial sclerosis, the vessel wall does not get enough nutrient supply, and the intima becomes weak due to nutrient metabolism disorder, and the strength of the intima directly affects the strength of the vessel wall. Thirdly, the hardened intima cannot stretch and contract freely with the pulsation of the artery, and under the impact of high pressure blood flow, accidental rupture can easily occur.
2. Weakness of the intima
The strength of the intima of the vessel wall directly affects the strength of the vessel wall. The weakness of the midmembrane is divided into two types: congenital and degenerative. Adopting healthy habits, avoiding hypertension and hyperlipidemia, and not smoking are effective means to prevent degenerative lesions of the mesentery.
3. Hypertension
Blood flow shock is a necessary condition to “create” arterial entrapment. Some data show that 80% of patients with arterial coarctation have high blood pressure, and the greater the fluctuation of blood pressure, the higher the risk of coarctation.
4. Trauma
A momentary blow to the aortic mesentery is likely to cause distortion and fracture of the mesentery, resulting in a false lumen.