Ischemic intestinal colic

　　How is ischemic intestinal colic caused? Briefly described as follows:

　　1, Arterial disease

　　The vast majority of this disease occurs on the basis of atherosclerosis, with the formation of wall thrombosis and atherosclerotic plaques in the arteries leading to luminal stenosis and even occlusion. At the same time as the vessels gradually occlude, collateral circulation in nearby vessels is also established, such as aneurysms, arterial stenosis, and large artery arteritis.

　　2, Venous obstructive disease

　　Venous thrombosis often occurs secondary to intra-abdominal infection, blood disease, trauma, pancreatitis, major abdominal surgery, connective tissue disease, long-term use of adrenal cortical hormones, and long-term use of oral contraceptives.

　　3, Low perfusion heart failure

　　Shocks caused by various reasons and insufficient blood volume, sudden drop in blood pressure, contraction of intestinal small vessels caused by drugs or certain endocrine substances.

　　4, Small vessel vasculitis

　　Diseases such as Wegener's granulomatosis, systemic lupus erythematosus, Behcet's disease, polymyositis, diabetes, hypertension,结节性多动脉炎and allergic purpura can also affect medium and small arteries, leading to luminal stenosis and occlusion.

　　5, Other

　　Increased intraluminal pressure, such as tumor obstruction, refractory constipation, and other abdominal trauma and radiation disease.

　　Due to malabsorption caused by intestinal ischemia, chronic diarrhea, steatorrhea, abdominal distension, and other symptoms may occur; the course of the disease is progressive, that is, with the progression of the disease, the patient may develop symptomatic anorexia, leading to weight loss and malnutrition. Patients with abdominal distension and constipation may develop acute mesenteric thrombosis and intestinal obstruction. Severe bleeding may manifest as melena, even leading to hemorrhagic shock.

　　Patients with this disease are often elderly, with a history of heart disease or peripheral vascular disease, with more males than females. Abdominal pain or discomfort is the most common symptom, the pain is often located in the upper abdomen or around the umbilicus, and can also be diffuse, radiating to the back and neck. The typical symptoms occur 15 to 60 minutes after a meal, lasting for 2 to 3 hours, and the initial symptoms may be episodic dull pain, which can gradually worsen with the progression of the disease, presenting as persistent dull pain and spasm-like colic pain, occasionally severe colic pain, which may be accompanied by nausea, vomiting, and so on. This is due to the fact that the blood supply at this time cannot meet the needs of the small intestine for digestion. The symptoms are parallel to the amount of food intake, and changing positions such as squatting or prone can alleviate the pain. Physical activity can trigger abdominal pain and intermittent claudication. This is because the blood supply to the lower limbs mainly comes from the visceral circulation, the superior mesenteric artery passes through the rectum through its anastomotic branches, communicating with the systemic circulation through the rectal branch of the internal iliac artery. When walking and moving, metabolism accelerates, causing a decrease in visceral blood flow, and consequently, abdominal pain occurs.

　　Physical examination usually has no special signs, about 80% of patients can hear systolic murmurs during upper abdominal auscultation, but they are not specific and not sensitive. Patients with a long course of disease appear chronic appearance, malnutrition, emaciation, soft abdomen, no tenderness, and even soft abdomen during pain attacks.

　　Typical clinical manifestations: postprandial paroxysmal upper abdominal pain, leading to weight loss due to the fear of eating too much, even abdominal distension, diarrhea, etc. The auxiliary examination exists evidence of ischemia and selective mesenteric angiography shows that the three arteries of abdominal aorta, superior mesenteric artery, and inferior mesenteric artery, at least two branches appear severe stenosis and occlusion, and tortuous thick collateral circulation blood supply arteries, can be diagnosed. Elderly patients with a history of atherosclerosis suggest potential possibilities.

　　The prevention of this disease lies in the active treatment of the primary disease and the elimination of the cause. Some people believe that 50% of the patients with chronic mesenteric artery ischemia are a precursor of acute mesenteric artery ischemia, and preventive angioplasty should be performed, but this measure is still controversial in the academic community. If there are symptoms such as fever, pale complexion, repeated vomiting, hematochezia, etc., one should go to the hospital for examination immediately and not delay the treatment time.

　　What examinations should be done for ischemic intestinal colic? Briefly described as follows:

　　1, Blood routine

　　Blood routine examination can detect relevant records of malnutrition.

　　2, Stool routine

　　3, Abdominal flat film

　　It should be routine, generally without characteristics, and can exclude gallbladder stones, urinary system stones, and obstructions.

　　4, Barium X-ray examination

　　It can manifest as simple narrowing of the small intestine; if it is intermittent multiple fibrous scars, it appears as segmental narrowing, known as the 'sausage string' sign. Diseases of the superior mesenteric artery often cause large-scale intestinal segmental lesions involving the small intestine to the colon.

　　5, Ultrasound examination

　　Doppler ultrasound can measure the blood flow velocity of the vessels, judge the degree and location of vascular stenosis, and display the size and location of plaques, stenosis, and occlusion in the main arteries within the abdominal cavity. Ultrasound examination can exclude diseases of the hepatobiliary and urinary systems.

　　6, Endoscopy

　　In addition to peptic ulcer and gastrointestinal tumors, gastroscopy can show erosion of the antrum and duodenum.

　　7, Angiography

　　The most reliable method for diagnosing this disease is to perform aortography on patients suspected of having the disease, and to choose angiography of the celiac artery, superior mesenteric artery, and inferior mesenteric artery to determine the nature, location, extent, and range of vascular stenosis and occlusion, and the establishment of collateral circulation. Lateral and anteroposterior films should be taken to show obvious atherosclerosis and some hemodynamic changes.

　　8, Tensiometry

　　Tensiometry (Tonometry) is a method to detect the intramural pH (pHI) of the intestinal wall. The tensiometry method before and after meals provides an effective means for diagnosing intestinal ischemia by measuring the intramural pHI of the small intestine.

　　Different symptoms have different dietary requirements. It is necessary to consult a doctor for specific dietary standards for specific diseases. The dietary principles for the acute phase of ischemic intestinal colic should be to fast and to avoid water. After the condition improves, do not eat spicy and difficult-to-digest foods, drink more soup and water, and eat some liquid and semi-liquid foods. Also, eat in small, frequent meals, do not drink alcohol, do not eat raw and cold foods, and do not eat greasy foods. Regular follow-up checks are necessary, such as abdominal ultrasound monitoring and angiography.

　　A brief description of the treatment methods for ischemic intestinal colic is as follows:

　　1. Internal Medicine Treatment

　　Treat the primary disease and eliminate the cause. For mild cases, conservative treatment with internal medicine is首选. Eat in small, frequent meals to expand blood vessels, reduce blood viscosity, and inhibit platelet adhesion and aggregation. Medications such as isosorbide dinitrate, mononitrate isosorbide, nifedipine, dipyridamole (Pentamin), sulprostone (prostaglandin E), opium, phenylephrine, and enteric-coated aspirin are used to improve intestinal circulation and alleviate clinical symptoms. It is also possible to use low-molecular-weight dextran, opium, etc., by infusion through a catheter or peripheral venous injection, which is more effective.

　　2. Surgical Treatment

　　For those who have failed conservative treatment with internal medicine and have severe stenosis of the celiac artery and mesenteric artery trunk confirmed by angiography, surgical treatment can be considered after improving malnutrition, correcting cardiovascular function and hypoxemia, etc. Common surgical methods include endarterectomy, bypass grafting with autologous great saphenous vein or artificial blood vessels, and vascular reimplantation. The choice of surgical method depends on the patient's general condition and anatomical relationship of the lesion site. Patients with extensive sclerosis and stenosis of small arteries or extensive small vessel vasculitis are not suitable for surgery.

　　3. Interventional Radiology

　　In recent years, the development of interventional radiology has promoted the development of non-surgical treatment for chronic mesenteric ischemic diseases, opening up new paths. Balloon angioplasty is performed by percutaneous puncture of the femoral artery, followed by balloon dilation at the stenotic sites of the celiac artery and superior mesenteric artery. In addition, placing titanium alloy stents at the above-mentioned main artery stenotic sites can achieve the same effect of unblocking blood flow and improving ischemia. It is suitable for those who are weak and cannot withstand surgery, and sometimes it can replace bypass grafting or endarterectomy.