non-occlusive mesenteric ischemia
Introduction
Introduction to non-occlusive mesenteric ischemia Non-obliterative mesenteric ischemia (non-obliterative vascular ischemia of mesentery) is an acute intestinal ischemia caused by superior mesenteric artery spasm, accounting for 20-30% of acute mesenteric ischemia, and the mortality rate is over 70%. The high mortality rate is not typical of the disease itself, and it is difficult to diagnose and is associated with other serious diseases. The earliest definition of non-occlusive mesenteric vascular ischemia was found in patients with small intestinal necrosis at autopsy, but no obvious occlusive changes in arteries or veins. Mesenteric blood circulation studies showed that mesenteric vasoconstriction, tissue hypoxia, ischemia-reperfusion injury, Causes non-occlusive mesenteric ischemia. basic knowledge The proportion of illness: 0.002% Susceptible people: more common in the elderly Mode of infection: non-infectious Complications: thrombosis
Cause
Non-occlusive mesenteric vascular ischemia
(1) Causes of the disease
Superior mesenteric artery spasm is a central component of non-occlusive mesenteric ischemia. It has been associated with sustained cardiac output reduction and hypoxic conditions, common in sepsis, congestive heart failure, arrhythmia, acute myocardial infarction, and severe Blood loss, etc., is an end-stage manifestation of the above diseases.
(two) pathogenesis
The basis of non-occlusive mesenteric vascular ischemia is compensatory persistent contraction of visceral blood vessels, slowing of blood flow through small arteries, red blood cell condensation and blood stasis, resulting in intestinal hypoxia and infarction, and shock patients using vasoconstrictor drugs. Prolonged vasoconstriction and accelerated intestinal gangrene. In addition, most patients with non-obstructive mesenteric infarction received digitalis, and animal experiments found that when the blood pressure of the straight blood vessels fell below 5.6 kPa (42 mmHg), the blood flow to the intestinal wall was less than 10 ml/ 100g, and for 8h, irreversible intestinal infarction will occur. Because the mesenteric vasospasm is mainly microvessels, intestinal ischemia is flaky, confined to the mucosa. The pathological features are extensive ischemic necrosis of mucosa with ulcer formation, mucosa The lower layer of blood vessels has a large amount of red blood cell deposits, and the serosal surface is dotted with necrosis, and perforation can occur in the late stage.
Prevention
Non-occlusive mesenteric ischemia prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Non-occlusive mesenteric vascular ischemia complications Complications thrombosis
Intestinal gangrene complicated by perforation.
Symptom
Non-occlusive mesenteric vascular ischemia symptoms common symptoms abdominal discomfort intestinal wall necrosis intestinal infarction abdominal muscle weakness myocardial infarction blood pressure drop shock intestinal bleeding bowel
It can be similar to acute arterial or venous mesenteric occlusion, but is more common in the elderly.
1. Early manifestations: The superior mesenteric artery occlusion occurs slowly within a few days, during which there may be prodromal symptoms of fatigue and abdominal discomfort.
(1) Abdominal pain: Abdominal pain of non-occlusive mesenteric ischemia is milder than acute mesenteric artery embolization or thrombosis. The degree of pain, nature and location are different, and 20% to 25% of patients have no abdominal pain.
(2) bloating and gastrointestinal bleeding: bloating and gastrointestinal bleeding without obvious cause may be an early manifestation of non-occlusive mesenteric ischemia and intestinal necrosis.
2. Intestinal necrosis: sudden bowel pain and vomiting at the beginning of intestinal infarction, followed by sudden drop in blood pressure and pulse rate, common fever, watery diarrhea or bloody stools, weakened bowel sounds, disappeared later, partial abdomen or Extensive tenderness, rebound tenderness and abdominal muscle tension suggest a full-thickness intestinal wall necrosis with a poor prognosis.
If there is a disease with a decrease in visceral circulation, if there are unexplained abdominal symptoms and signs, the possibility of the disease should be highly suspected.
Examine
Non-occlusive mesenteric ischemia
Blood routine
(1) White blood cell count: usually exceeds 15 × 109 / L, or with the left side of the nucleus.
(2) thrombocytopenia.
(3) Hemoglobin and red blood cell ratio are increased, suggesting that plasma is largely lost and blood is concentrated.
2. Serum enzyme: elevated serum amylase; elevated serum LDH, SGOT, SGPT, CPK suggest that intestinal ischemia and necrosis are irreversible.
3. Serum electrolytes: elevated serum phosphorus, patients with hyperphosphatemia.
4. Blood gas analysis: pH decreased, SB decreased, BE negative value, carbon dioxide binding decreased, suggesting the presence of metabolic acidosis.
1. X-ray abdominal plain film: early, clinical manifestations like acute abdomen, and X-ray abdominal plain film is normal, suggesting early acute mesenteric ischemia; late, 20% to 25% of patients with intestinal obstruction, intestinal wall edema, The manifestation of gas accumulation in the intestinal lumen suggests a full-thickness of the intestinal wall.
2. Selective superior mesenteric artery angiography: The image of the superior mesenteric artery is:
1 The initial mesenteric artery is narrow.
2 The superior mesenteric artery trunk expansion and contraction alternate.
3 mesenteric vascular arch.
4 intravascular filling defects.
Cell count: usually exceeds 15 × 109 / L, or with the left side of the nucleus.
(2) thrombocytopenia.
(3) hemoglobin and hematocrit: both increased, suggesting that plasma is largely lost and blood is concentrated.
2. Serum enzyme: elevated serum amylase; elevated serum LDH, SGOT, SGPT, CPK suggest that intestinal ischemia and necrosis are irreversible.
3. Serum electrolytes: elevated serum phosphorus, patients with hyperphosphatemia,
4. Blood gas analysis: pH decreased, SB decreased, BE negative value, carbon dioxide binding decreased, suggesting the presence of metabolic acidosis.
5. X-ray abdominal plain film: early, clinical manifestations like acute abdomen, and X-ray abdominal plain film is normal, suggesting early acute mesenteric ischemia; late, 20% to 25% of patients with intestinal obstruction, intestinal wall edema, The manifestation of gas accumulation in the intestinal lumen suggests a full-thickness of the intestinal wall.
6. Selective superior mesenteric artery angiography: The image of the superior mesenteric artery is:
1 The initial mesenteric artery is narrow.
2 The superior mesenteric artery trunk expansion and contraction alternate.
3 mesenteric vascular arch.
4 intravascular filling defects.
Diagnosis
Diagnosis and diagnosis of non-occlusive mesenteric ischemia
1. History: Those with the following medical history are at high risk of non-occlusive mesenteric ischemia:
1 acute myocardial infarction accompanied by shock, congestive heart failure, arrhythmia;
2 burns accompanied by a decrease in blood volume;
3 abscess, pancreatitis;
4 hemorrhagic shock;
5 Adrenalin alpha receptor agonists and digitalis drugs that have the function of contracting visceral blood vessels are being used.
2. Clinical manifestations: sudden onset of severe abdominal cramps, accompanied by watery diarrhea or bloody stools, fever, weakened or disappeared bowel sounds; local or extensive abdominal tenderness, rebound tenderness and abdominal muscle tension.
3. Auxiliary examination: The superior mesenteric artery angiography revealed that the superior mesenteric artery had a stenosis at the beginning of the majority branch, the shape of the intestine changed irregularly, and the blood vessels in the intestinal wall were not well filled.
Identification of non-occlusive mesenteric vascular ischemia
The disease must be differentiated from mesenteric artery embolism and thrombosis.
