Aneurysm is not a tumor, it is a local weakness of the arterial wall under the action of pathological factors and then dilates outward, resembling an “aneurysm” in appearance, hence the name. What we usually call a tumor is an abnormal proliferation of cells, while malignant tumors are mainly fatal in terms of systemic metastasis. Although aneurysm and tumor are completely different concepts, its rupture is more dangerous and fatal than any tumor.
Aneurysm has a proper name in English, “aneurysm”, which is a Greek word that originally meant “dilatation”. “When an artery dilates, the lesion is called an aneurysm, and if the aneurysm ruptures, fatal bleeding often occurs. Like an inflated rubber hose, when it ruptures, the water inside the hose gushes out. When an aneurysm ruptures, all that gushes out is blood, and the patient can die within minutes from the hemorrhage. Therefore, “aneurysm” is like a time bomb buried in the body, and its “explosion” can take a person’s life in an instant. Zhao Zhiqing, Department of Vascular Surgery, Shanghai Changhai Hospital
Classification of aneurysm
According to the pathology, there are three types of aneurysms: “clogged aneurysm”, “pseudoaneurysm” and “true aneurysm”.
Clogged aneurysm: In terms of the structure of arteries, the arterial wall is divided into three layers, including the inner membrane, middle membrane and outer membrane. When the body’s own high blood pressure, i.e., high speed and high pressure blood flow, tears the inner and middle membranes of the artery, and the blood flow rushes downward, the outer membrane of the artery expands and swells into an aneurysm, and the lumen of the artery changes from one to two or three, which is called an interstitial aneurysm. These aneurysms are usually found in the thoracic aorta.
True aneurysm: The wall of the artery swells under the effect of high speed and high pressure blood flow, and a section of the artery swells into a spherical shape, thus forming an aneurysm. The most common site for true aneurysms is the abdominal aorta.
Pseudoaneurysm: Most often occurs after trauma, such as an edge injury, or can be infectious. The artery wall is partially ruptured and a hematoma is formed around the artery. The hematoma is connected to the artery and the shadow seen on the image is not the artery wall but the hematoma, which is a pseudoaneurysm. Pseudoaneurysms are most common in peripheral arteries.
There are “thoracic aortic aneurysm”, “abdominal aortic aneurysm”, “visceral aneurysm” and “peripheral aneurysm” according to the location. “Peripheral aneurysm”.
Thoracic aortic aneurysm: In the thoracic aorta, true aneurysm, pseudoaneurysm and intercalated aneurysm can occur, and the most common one in China is “thoracic aortic intercalated aneurysm”, which is a more dangerous disease. When a thoracic aortic coarctation aneurysm ruptures and tears, there will be near-death pain, near-death sweating, near-death inability to move and near-death breathing, and the patient will deeply feel that he or she is about to die. The pain is located in the dorsal thorax and is dominated by back pain, and many are misdiagnosed as heart attack. Many patients have an EKG and find nothing abnormal, so the doctor is relieved, but in fact, this is the time to be more vigilant, and if misdiagnosed it may cause the patient to die suddenly, and the possibility of entrapment aneurysm should be considered in time. American athlete Hyman is the victim of a ruptured thoracic main entrapment aneurysm, a disease that is an acute and fierce killer. Thoracic aortic aneurysm is most associated with hypertension, especially with violent fluctuating hypertension, sometimes with a sudden rise in blood pressure after drinking alcohol and emotional excitement, and the patients are mostly middle-aged and elderly.
Abdominal aortic aneurysm: It is predominantly a true aneurysm, but there are often pseudoaneurysms and entrapment aneurysms as well. The clinical manifestations are often not very clear. The formation of abdominal aortic aneurysm is a slow process, and this process makes people pay less attention to it. It is recommended that people pay attention to abdominal aorta by ultrasound, CT and MRI during physical examination. The incidence of abdominal aortic aneurysm population is currently increasing. Patients will have dull vague pain in the abdomen, sometimes a boomerang mass on their own touch, occasionally affecting digestion, it is an insidious killer, often with a focus on ultrasound and other imaging screenings. Ruptured abdominal aortic aneurysm is another story, it is also a dangerous killer. The process of rupture and tearing of abdominal aortic aneurysm is just like that of a coarctation aneurysm, it starts with severe pain, mainly abdominal pain and low back pain, a sense of near death, drop in blood pressure, pale face, fast pulse followed by slow pulse, shock, many patients die as soon as the abdominal aortic aneurysm ruptures, it is very dangerous.
Visceral aneurysm: mainly includes superior mesenteric aneurysm, hepatic aneurysm, splenic aneurysm, renal aneurysm, etc. In recent years, with the improvement of imaging, more of them have been detected. Visceral aneurysm is not the same as visceral hemangioma. A hemangioma is a capillary that does not develop as it should when it develops, but forms a hemangioma mass, which is a completely different concept from aneurysm formed by the aorta. The symptoms of visceral aneurysm are related to the blood supply of related internal organs, such as superior mesenteric artery aneurysm, which often causes poor blood supply to the superior mesenteric artery and affects the patient’s digestive function, and the patient may find that he or she has no appetite and always has diarrhea, which may also be complicated by superior mesenteric artery stenosis in the midst of this. Other hepatic aneurysms, splenic aneurysms, etc., will have different symptoms in their corresponding target organs. Most of the visceral aneurysms are not palpable masses from outside the body, and the vast majority need to be diagnosed on imaging.
Peripheral aneurysms: It includes carotid aneurysms, subclavian aneurysms, brachial aneurysms, iliac aneurysms, femoral aneurysms, and N aneurysms. Carotid aneurysm is a bit different in that it tends to cause cerebral ischemia, but because it is relatively superficial, it is easy to detect, and carotid aneurysms are 50/50 true and false. In addition, it has to be distinguished from carotid body aneurysm, which is a true tumor, a solid aneurysm that grows from the nerve tissue at the bifurcation of the carotid artery. Subclavian aneurysm is more insidious and also divided into true and false. It tends to compress the nerves of the upper limbs, with arm pain, numbness and weakness, and requires imaging. Iliac aneurysms, femoral aneurysms, and N aneurysms are often involved in the blood supply function, with insufficient blood supply to the lower extremities and compromised walking.
After recognizing an aneurysm, let’s look at how to deal with it. The most advanced approach to treating large aneurysms is minimally invasive endoluminal isolation, especially in the case of aneurysms with a coarctation. Open surgery is very invasive, and most aneurysm patients are elderly and often cannot tolerate such a large procedure. Endoluminal isolation mainly uses a stent with artificial blood vessels to isolate the aneurysm from the high-speed blood flow, thus avoiding rupture of the aneurysm. Some peripheral aneurysms are still mainly resected surgically.