Postprandial abdominal pain
Introduction
Introduction Ischemic intestinal colic, also known as chronic mesenteric ischemia, refers to severe paroxysmal upper abdominal cramps or peri-umbilical pain after repeated episodes.
Cause
Cause
(1) Causes of the disease
1. Arterial disease: The vast majority occur on the basis of atherosclerosis. The wall thrombus of the artery and the formation of atheromatous plaque cause stenosis or even occlusion. At the same time as the blood vessels gradually occlude, the collateral circulation of nearby blood vessels is also established, such as aneurysms, arterial stenosis, and arteritis.
2. Venous occlusive disease: Intravenous thrombosis often occurs in intra-abdominal infections, blood diseases, trauma, pancreatitis, major intra-abdominal surgery, connective tissue disease, long-term use of adrenocortical hormones and long-term use of oral contraceptives.
3. Low perfusion heart failure: shock and blood volume deficiency caused by various reasons, sudden drop in blood pressure, drug or some endocrine caused small intestinal vasoconstriction.
4. Small vascular inflammatory diseases: such as Wegener granulomatosis, systemic lupus erythematosus, Behcet's disease, dermatomyositis, diabetes, hypertension, nodular polyarteritis and allergic purpura may also involve the small and medium arteries The cavity is narrow and occluded.
5. Others: increased intra-intestinal pressure such as tumor obstruction, intractable constipation and so on. Abdominal trauma and radiation sickness.
Incidence is often the result of multifactorial synergy. The celiac artery and the superior and inferior mesenteric arteries are involved at the same time.
(two) pathogenesis
The vast majority of intestinal blood supply comes from the three main branches of the ventral side of the abdominal aorta, namely the celiac artery, superior mesenteric artery and inferior mesenteric artery.
The superior mesenteric artery has more than 10 branches for the small intestine, while the ileum, right colon and middle colon are respectively supplied with the same name; the main branch is supplied from the distal end of the duodenum to the distal end of the transverse colon. The superior mesenteric artery is fan-shaped, and there are 3 to 5 arterial arches connected to each other before the terminal arteries, and there are lateral branches communicating between the arches. In the three main branches, the superior mesenteric artery has the largest lumen.
The inferior mesenteric artery is the smallest of the three main branches, and its branch supplies the distal end of the transverse colon, the descending colon, the sigmoid colon, and the proximal rectum, and branches are connected by the Riolan arterial arc (formed by the transverse mesenteric membrane) and the peripheral arteries are connected to the superior mesenteric artery. Another branch is connected to the middle and lower rectal artery of the internal iliac artery (systemic circulation).
In addition to the above two supply intestines, other abdominal organs such as the stomach, liver, spleen, pancreaticoduodenal, etc. are supplied by the celiac artery, and are connected to the superior mesenteric artery via the pancreas and duodenal artery. This main branch has a large number of blood supply, and each question is like a network-like communication, so it is rare to have an ischemic infarction.
The visceral shunt of the aorta is not much, about 30% of the cardiac output. The blood flow per unit tissue of the small intestine is about 5 times that of the stomach and 2 times that of the colon. It is generally believed that the blood flow of the mucosa accounts for 70% of the total blood flow of the intestine.
The relationship between arterial oxygen partial pressure and blood flow in the mesentery, vascular resistance and vascular pressure determines the supply of internal organs. Mesenteric blood flow is directly proportional to the pressure of the mesenteric vessels and inversely proportional to the resistance of the mesenteric vessels. The oxygen uptake of the stomach and intestines is constant, and although the range of changes in blood flow is quite extensive to prevent damage caused by hypoxia, the intestinal mucosal metabolism is most active and therefore most sensitive to hypoxia. During the meal, the blood flow of the small intestine increases by 30% to 130%, which is beneficial to the redistribution of blood in the mucosa and submucosa.
Because there are more collateral connections between the celiac artery, superior mesenteric artery and the inferior mesenteric artery, when a main branch, such as the superior mesenteric artery, is chronically occluded, the collateral artery of the other main branches can compensate for blood supply. Therefore, symptoms rarely occur. Even if a sudden occlusion (such as an embolus), the collateral artery may supply a considerable amount of blood in a short period of time, and the intestinal tissue does not cause necrosis. When the occlusion is released, the side branch blood supply also stops. Generally, the intestinal tube is more tolerant to ischemia. When the diameter of the superior mesenteric artery is reduced by 80% or the blood supply is reduced by 75%, the intestinal wall may have no appearance change within 12 hours. Only when 2 to 3 large branches of the abdominal aorta are involved in occlusion or severe stenosis, the main mesenteric artery is severely stenotic, and the collateral circulation is insufficiently compensated, the blood flow is significantly reduced, the chronic blood supply to the intestinal wall is incomplete, and intestinal ischemia symptoms occur.
In addition to the above-mentioned arteries, the blood supply to the intestine is also reduced by the cyclic arterial pressure (shock) and increased arteriolar resistance (adrenalin, digitalis preparations, and vasculitis complicated by connective tissue diseases such as lupus erythematosus) Factors affect the ischemia. But there are also local adjustments, which are achieved by internal and external mechanisms. Local metabolic factors and muscle tissue can alter the tension of the vessel wall and regulate local blood flow.
Examine
an examination
There were no special signs in the physical examination. About 80% of the patients had audible and systolic murmurs in the upper abdomen, but they were not specific and were not sensitive. Chronic illness, malnutrition, and weight loss in the elderly. The abdomen is soft and has no tenderness, and the abdomen is soft even when the pain occurs.
Typical clinical manifestations: postprandial episodes of upper abdominal pain, often do not dare to eat more, resulting in weight loss, and even bloating, diarrhea and so on. Auxiliary examination of evidence of ischemia and selective mesenteric angiography showed three major arteries of the abdominal aorta, superior mesenteric artery, and inferior mesenteric artery. At least two of the stenotic and occlusive sites with large stenosis and occlusion and extensive collateral circulation were included. Can be diagnosed. Older people with a history of atherosclerosis suggest potential possibilities. Early clinical manifestations are atypical, and laboratory examinations, radiological examinations, and ultrasound Doppler are normal. In addition, angiographic examinations are easily overlooked for various reasons, so early or preoperative diagnosis is very difficult.
Diagnosis
Differential diagnosis
Stomach ulcer
Upper abdominal pain often occurs 0.5 to 1 hour after a meal, and gradually relieves itself after 1 to 2 hours, but the episode has periodicity, which is easy to occur in the early spring and late autumn season. The pain can be relieved by taking antacids and mucosal protective agents, and the gastroscopy can be confirmed.
2. Chronic pancreatitis
There are symptoms such as abdominal pain, weight loss, diarrhea, and indigestion after eating, similar to this disease. According to abdominal B-mode ultrasound, CT, MRCP, ERCP and abdominal plain film examination can be identified.
Underarm arch ligament compression syndrome: more common in young women, male to female ratio of 1:3. It is characterized by intermittent upper abdominal dull pain unrelated to diet, with nausea, vomiting or diarrhea. Weight loss, weight loss and malnutrition. The physical examination can be heard in the abdomen with a loud systolic murmur. Most of the pathogenesis is caused by ischemia of the inferior orthocardial ligament or celiac ganglion compression of the beginning of the celiac artery. Angiography can confirm compression or stenosis, distal dilatation, and no atherosclerosis.
It should also be differentiated from gastrointestinal tumors, Crohn's disease, Crohn's disease, pseudomembranous colitis, hemorrhagic enteritis, pancreatic cancer, biliary tract disease, and renal colic. Some types of Crohn's disease may be chronic forms of ischemic bowel disease, especially those with proliferative occlusive vascular disease.
