superior mesenteric artery embolization
Introduction
Introduction to superior mesenteric artery embolization Upper mesenteric artery embolization refers to the emboli of other emboli that is detached from the blood to the superior mesenteric artery and retains its end, resulting in blood supply to the artery, acute ischemic necrosis of the blood supply to the intestine, and large diameter of the superior mesenteric artery. The abdominal aorta is inclined at an angle, and the embolus is easy to enter. Therefore, the disease is more common in the clinic, accounting for 40% to 50% of acute mesenteric ischemia. The embolus is usually from the heart's wall thrombus, so it is more common in rheumatic heart disease, coronary heart disease, infective endocarditis and recent myocardial infarction. In addition, the embolus comes from atherosclerotic plaque and occasional bacterial emboli. These emboli are detached spontaneously or during catheter examination. basic knowledge Proportion of disease: The incidence rate is 0.3% to 0.7% of the total number of patients with intestinal obstruction Susceptible people: no specific population Mode of infection: non-infectious Complications: shock
Cause
Cause of superior mesenteric artery embolism
(1) Causes of the disease
Embolism embolization (50%):
The embolus of the superior mesenteric artery is mainly derived from the heart, such as the wall plug after myocardial infarction, the valvular sputum of subacute bacterial endocarditis, the neoplasm of rheumatic heart valve lesion and the shedding of the left and right atrial appendage thrombus. Etc.; can also be derived from aortic atherosclerosis of the wall thrombus or atherectomy of atherosclerotic plaques and abscess or sepsis of bacterial emboli.
Anatomical factors (25%):
The occurrence of mesenteric artery embolism is also related to the anatomy of the superior mesenteric artery. The superior mesenteric artery is separated from the abdominal aorta at an acute angle, parallel to the aorta, and the lumen is thicker, consistent with the direction of the abdominal aortic blood flow. The embolus is easy to enter, causing blood vessel embolism at the stenosis or bifurcation of the blood vessel, and is more common in the site of the middle part of the colonic artery or below.
(two) pathogenesis
Once the mesenteric blood vessels are embolized, the intestinal tube of the blocked arterial supply area has blood circulation disorder, intestinal tube ischemia, hypoxia makes the intestinal tube tarnish, the color is pale, and the intestinal mucosa is not easy to tolerate ischemia. If the ischemia time exceeds 15 minutes, the small intestinal mucosa villi The structure will be destroyed and shedding, and then the blood in the intestinal wall will be stagnant, congested, edematous, the intestines will lose tension, and there will be edema and edema. A large amount of plasma will infiltrate into the intestinal wall, and the intestinal wall will show hemorrhagic necrosis. A large amount of plasma will exude into the abdominal cavity and intestinal lumen. The circulating blood volume is sharply reduced, the bacteria in the intestinal cavity are multiplied, and the toxic metabolites that are necrotic due to intestinal ischemia and hypoxia are continuously absorbed, resulting in hypovolemia, toxic shock, intestinal necrosis, intestinal dilatation, and peristalsis disappearing. Bloody intestinal obstruction.
The location of mesenteric artery embolization is different, and the extent of intestinal ischemia is different. Embolization occurs at the entrance of the superior mesenteric artery, which can cause ischemic necrosis of all small and right colons below the Treitz ligament; embolization occurs below the branch of the middle cerebral artery. Causes most of the small intestine necrosis; occurs in a branch artery of the intestinal tract and the collateral circulation is good, no necrosis occurs; but the infarction occurs in the peripheral arterial embolization, and the intestinal tube in the supplied area is necrotic.
Prevention
Superior mesenteric artery embolism prevention
It is very important to maintain a good attitude, to maintain a good mood, to have an optimistic, open-minded spirit, and to be confident in the fight against disease. Prevention and treatment of primary diseases that cause thrombosis.
Complication
Superior mesenteric artery embolism Complications
The complication of superior mesenteric artery embolization is segmental intestinal ischemia and necrosis, which is the most serious complication, the incidence rate is 10% to 25, and there may be complications such as peripheral circulatory failure and shock.
Symptom
Symptoms of superior mesenteric artery embolism common symptoms mobile dullness abdominal muscle tension intestinal circulatory failure abdominal tenderness diarrhea abdominal pain atherosclerosis
The occurrence of this disease, more men than women, more frequent between 40 and 60 years old, most patients have a history of heart disease that can form arterial emboli, such as myocardial ventricular aneurysm, atrial arrhythmia, rheumatic valvular disease, A history of aortic atherosclerosis, 15% to 20% of patients have a history of other arterial embolism in the past.
The disease occurs suddenly, sudden severe abdominal pain, accompanied by frequent vomiting, initial abdominal pain symptoms and signs do not match, abdominal pain is severe and abdominal signs are mild, when the patient has bloody watery vomiting, or diarrhea with dark red bloody stools, abdominal pain symptoms Reduced, but there is abdominal tenderness, rebound tenderness, abdominal muscle tension, bowel sounds weakly disappeared, percussive examination with mobile dullness, abdominal puncture can draw hemorrhagic exudate, this time indicates that the intestine has infarction, with Patients with progression of the disease may present signs of peripheral circulatory failure.
Examine
Examination of superior mesenteric artery embolism
Laboratory inspection
1. Blood: The white blood cell count is significantly increased, mostly in (25 ~ 40) × 109 / L.
2. Hematocrit: The hematocrit is elevated due to blood concentration.
3. Blood gas analysis: pH decreased, SB decreased, BE was negative, cohesive decline in carbon dioxide binding, etc., suggesting metabolic acidosis occurred.
4. Serum enzymology examination: serum LDH, SGOT, SGPT, and CPK were observed to increase.
Film degree exam
1. X-ray inspection:
(1) Abdominal plain film: There is no special performance in the early stage. The image shows that the large and small intestines have mild or moderately enlarged inflation, but it can help to eliminate other diseases. In the late stage, due to the large amount of fluid in the intestinal cavity and abdominal cavity, the abdominal cavity is generally increased in density.
(2) Selective celiac angiography: It can be used to understand the condition of the celiac trunk and mesenteric artery and its branches. According to the sudden interruption of the contrast agent, the embolization site is determined, which is of great value for the diagnosis.
2. Doppler ultrasound examination:
According to the direction and speed of blood flow, the location of the embolization is judged, but in the case of intestinal obstruction, flatulence can interfere with the diagnosis.
3. Diagnostic abdominal puncture drainage:
Bloody liquid can be withdrawn.
Diagnosis
Diagnosis and differentiation of superior mesenteric artery embolization
diagnosis
1. History: Previous patients have a history of heart disease or arterial embolism.
2. Clinical features: sudden severe abdominal pain, and signs of mild, accompanied by vomiting and dark red bloody stools.
3. Laboratory examination: combined with clinical manifestations, increased white blood cell count, serum enzyme LDH, SGOT, SGPT, CPK increased, the possibility of mesenteric artery thrombosis should be considered.
4. Selective angiography: can help the diagnosis, the superior mesenteric artery embolism often occurs 3 to 8 cm below the opening of the superior mesenteric artery, the contrast agent shows a sudden interruption, forming a "new moon sign", in addition to diagnostic abdominal puncture drainage And abdominal Doppler ultrasonography is also helpful for diagnosis.
Mesenteric artery embolization needs to be differentiated from acute abdomen caused by other organs in the abdomen: perforation of the digestive tract ulcer, acute pancreatitis, intestinal torsion, intussusception, ovarian cyst torsion, acute appendicitis, etc. In addition, there is still a need for mesenteric artery thrombosis. The formation is differentiated from the sputum. The former is slow onset, and the thrombus is often formed at the opening of the superior mesenteric artery. The contrast agent is interrupted within 3 cm from the aorta. The latter is caused by vasospasm. Obstruction site.
