Pseudo-obstruction

Introduction to pseudo-intestinal obstruction Intestinalpseudo-obstruction IPO (intestinalpseudo-obstructionIPO) is due to neurosuppression, toxin stimulation or intestinal wall smooth muscle disease, resulting in intestinal wall muscle dysfunction, clinical signs and symptoms of intestinal obstruction, but no intestinal intestinal mechanical obstruction The existence of factors, it is also called dynamic intestinal obstruction, is a syndrome without intestinal obstruction, according to the course of acute and chronic, paralytic ileus and spastic intestinal obstruction are acute pseudo-intestinal obstruction, chronic pseudo- There are two types of intestinal obstruction: primary and secondary. basic knowledge The proportion of illness: 0.05--0.08% Susceptible people: no special people Mode of infection: non-infectious Complications: dysphagia, urinary retention, anemia, malnutrition

Cause of pseudo intestinal obstruction

(1) Causes of the disease

Genetic factors (30%)

Also known as chronic idiopathic pseudo-intestinal obstruction, officially named by Maldonado in 1970, its cause is unclear, may be related to chromosomal dominant inheritance, many patients have a family history, and can involve some organs other than the gastrointestinal tract (such as Bladder), so some people call it familial visceral myopathy or hereditary jejunal visceral myopathy.

Disease factor (30%)

(1) Small intestinal smooth muscle disease: 1 collagen vascular disease: scleroderma, progressive systemic sclerosis, dermatomyositis, polymyositis, systemic lupus erythematosus; 2 invasive muscle disease: amyloidosis; Onset muscle disease: myotonic dystrophy, progressive muscular dystrophy; 4 others: waxy pigmentation, non-tropical stomatitis diarrhea.

(2) endocrine diseases: 1 hypothyroidism; 2 diabetes; 3 pheochromocytoma.

(3) Neurological diseases: Parkinson's disease, familial autonomic dysfunction, Hirshsprung disease, Chang disease, psychosis, small bowel ganglion disease.

Drug factor (15%)

1 toxic drugs: lead poisoning, mushroom poisoning; 2 drug side effects: phenothiazines, tricyclic antidepressants, anti-Parkinson's disease drugs, ganglion blockers, clonidine.

Electrolyte disturbance (10%)

Low blood, low blood calcium, low blood magnesium, uremia.

Other (5%)

Empty ileal bypass, jejunal diverticulum, spinal cord injury, malignant tumor.

(two) pathogenesis

The pathophysiological changes of pseudo-intestinal obstruction are essentially an intestinal motility disorder caused by myogenic or neurogenic or endocrine control disorders in the intestine. The movement of the normal small intestine is affected by its own smooth muscle, autonomic nervous system and gastrointestinal hormones. Regulation, spontaneous electrical activity of small intestinal smooth muscle cells controls contraction of the small intestine. There are two types of electrical activity in the small intestine. One is slow wave, which itself does not cause muscle contraction, but it can determine the frequency of muscle contraction; the other is peak Potential, which occurs on the basis of slow waves, is activated by the release of various neurotransmitters such as acetylcholine, adrenaline, serotonin, etc. through the myenteric plexus. The peak potential appears at the beginning of muscle contraction, and the autonomic nervous system is in the small intestine. Exercise also plays an important role. Parasympathetic nerves excite the movement of the small intestine, while the sympathetic nerves act as inhibitors. Therefore, when the parasympathetic activity is inhibited or the sympathetic activity is enhanced, the inhibition of intestinal movement can be caused. Similarly, the gastrointestinal tract Hormones are also involved in regulating the movement of the small intestine, such as motilin, which promotes the absorption of small intestine muscles. , And secretin and glucagon can be suppressed shrinkage, and therefore, a part of any exception will produce motion of the small intestine dysfunction.

Antaras et al observed cases of 9 families, 4 families with gastrointestinal and bladder smooth muscle atrophy, degeneration and fibrosis, mitochondrial swelling under electron microscope, and decreased number of muscle fibers. Schufffer et al reported a normal smooth muscle in a family. However, the intramuscular plexus of the esophagus, small intestine, and colon has degenerative changes. About one-third of the nerve cells contain a circular eosin substance, and there are inclusion bodies in the nucleus, which are composed of irregularly arranged filaments, using the Smith method. Silver staining showed that the argyrophilic neurons were significantly reduced, the silver neurons were swollen, the boundary was unclear, the axis broke or disappeared, and the Schwann cell proliferation was replaced. Therefore, according to the basic pathological changes, the pseudo-small intestinal obstruction was clinically divided. 2 categories: one is the degenerative change of small intestine smooth muscle, which is myopathy pseudo-small intestinal obstruction; the other is the degenerative change of the intermuscular or submucosal plexus, which is neuropathic pseudo-small intestinal obstruction, in addition, Some people think that substance P can cause smooth muscle contraction and cause nerve depolarization. When its secretion is reduced, it can lead to this disease. It is also reported that the level of prostaglandin E is elevated. Smooth muscle relaxation and disease, effective treatment with indomethacin.

Among them, chronic pseudo-intestinal obstruction caused by systemic sclerosis is more common. The main pathological changes are smooth muscle atrophy and fibrosis of the intestinal wall, and the lesions of the circumflex muscle are very serious. Amyloidosis can be found in the muscle layer of the intestinal wall. Deposition; mucinous edema has mucinous edema in the muscular layer of the intestinal wall; diabetes often has no significant changes in the intestinal wall muscle and intermuscular nerve plexus.

Primary chronic pseudo-intestinal obstruction, also known as chronic idiopathic pseudo-intestinal obstruction, can involve some organs other than the gastrointestinal tract (such as the bladder), so some people call it familial visceral myopathy or hereditary jejunal viscera. Myopathy. According to the lesions of the intestinal wall, it can be divided into the following three types.

(1) Myopathy pseudo-intestinal obstruction (visceral myopathy): The lesion is mainly in the smooth muscle of the intestinal wall and can be divided into familial or sporadic. The main pathological change is the degenerative change of the intestinal wall or longitudinal muscle. The reason is that sometimes the muscles are completely atrophied and replaced by collagen.

(2) Neuropathic pseudo-intestinal obstruction (visceral neuropathy): The lesion is mainly in the nerves of the intermuscular plexus of the intestinal wall, which may be sporadic or familial. In 1969, Dyer et al reported that the pathological changes mainly occurred in the intermuscular wall of the intestinal wall. The plexus, which is characterized by degeneration and swelling of neurons and neuronal processes, and in some cases, other parts of the nervous system are involved.

(3) Acetylcholine receptor function-deficient pseudo-intestinal obstruction: no abnormalities in muscle or nerve organic abnormalities, but physiological tests have abnormalities in intestinal motor function. In 1981, Bannister et al reported a case of pseudo-intestinal obstruction, which was sectioned. No histological changes in muscle or neurological disease were found, and the occurrence of this case may be related to defects in muscarinic acetylcholine receptor function in intestinal smooth muscle.

Pseudo intestinal obstruction prevention

Active and effective treatment of neurological diseases (such as Parkinson's disease, enteric ganglionitis, etc.), connective tissue diseases (such as systemic lupus erythematosus, dermatomyositis and polymyositis, etc.), endocrine diseases (such as diabetes, chromaffin cells) Tumors, etc., as well as attention to the use of certain drugs (such as: phenol oxazines, ganglion blockers, morphine, etc.) may cause chronic pseudo-intestinal obstruction to prevent the occurrence of pseudo-intestinal obstruction.

Pseudo intestinal obstruction complications Complications, dysphagia, urinary retention, anemia, malnutrition

Pseudo-intestinal obstruction can cause dysphagia when the esophagus is involved, bladder involvement can have urinary retention, eye muscle paralysis can occur when the eye muscle is involved, upper eyelid ptosis, chronic pseudo-intestinal obstruction due to malabsorption, anemia, hypoproteinemia Such as malnutrition.

Symptoms of pseudo-intestinal obstruction Common symptoms Nausea and abdominal pain Diarrhea Intestinal flatness and bowel dysphagia Difficulty constipation Malignant disease Aphid intestinal obstruction

The disease can occur at any age, more women than men, with a family history, mainly characterized by chronic or recurrent nausea, vomiting, abdominal pain, bloating, abdominal pain often located in the upper abdomen or umbilical, persistent or paroxysmal, often With varying degrees of diarrhea or constipation, some diarrhea and constipation alternate, or have difficulty swallowing, urinary retention, incomplete bladder emptying and repeated urinary tract infections, thermoregulatory dysfunction, dilated pupils, etc., physical examination has bloating, Tenderness, but no muscle tension, audible and vibrating sound, bowel sounds weakened or disappeared, weight loss, malnutrition common.

Examination of pseudo-intestinal obstruction

There may be anemia, giant platelets, hypoproteinemia, low calcium, low folic acid, iron deficiency, etc., false intestinal obstruction may have small intestinal malabsorption and intestinal bacterial overgrowth, feasible related examination to confirm the diagnosis.

X-ray inspection

(1) Abdominal X-ray film: In the acute episode of pseudo-intestinal obstruction, the abdominal X-ray film can be seen in the stomach, the small intestine and the colon are inflated and have multiple liquid levels, and the visceral myopathy is more dilated than that caused by visceral neuropathy. In severe cases, the abdominal plain film of patients with mechanical intestinal obstruction showed no gas in the distal intestinal fistula, and the mucosal folds of the proximal inflatable dilated intestinal fistula were clear. A few plain intestinal obstruction abdominal plain films showed small intestinal gas cysts, and even appeared. At the time of pneumoperitoneum, attention should be paid to comprehensive consideration of physical signs and medical history to avoid misdiagnosis as intestinal perforation.

(2) barium meal examination: the lesions due to primary chronic pseudo-intestinal obstruction can affect the whole gastrointestinal tract, barium meal examination must be from esophagus to rectum, myopathy pseudo-intestinal obstruction can be seen esophageal dilation, peristalsis disappears; neuropathy Sexual intestinal obstruction can be seen in the esophagus, multiple and confusing contractions and delays in emptying, sometimes similar to the performance of achalasia, about one-third of patients with esophageal stenosis, this performance often suggests false Intestinal obstruction is caused by progressive systemic sclerosis. Except for jejunum sputum, patients with pseudo-intestinal obstruction generally have delayed X-ray manifestations of gastric dilatation and gastric emptying. Duodenum often dilates, especially myopathy. Pseudo-intestinal obstruction is even more, the diameter can reach 11.5cm, the tincture moves very slowly in the duodenum, and even stays for several days. The visceral muscle disease patients have small intestinal peristalsis, the tincture moves down slowly, the internal organs Neurological disease can be seen in the small intestine with active but uncoordinated contraction. Although the expectorant can reach the cecum in normal time, but the intestinal peristalsis is uncoordinated, there is still barium in the small intestine after 24h, visceral myopathy and some progressive systemic hardening Human disease, colon often long, the expansion of the bag-shaped disappeared, nor emptied completely, Familial visceral polyneuropathy, barium enema can be seen colonic diverticulitis extensive fusion, normal colonic emptying.

(3) small bowel enema; if it is necessary to distinguish between pseudo-intestinal obstruction and mechanical intestinal obstruction, small bowel enema can be performed by inserting a soft catheter with a copper ball into the jejunum and injecting it into the jejunum. Tincture, for fluoroscopy or radiography, the diagnostic rate of small intestine organic lesions is 98%. If it is pseudo-intestinal obstruction, no organic obstructive lesions are visible.

2. Digestive pressure test

Esophageal manometry shows that the lower end of the pressure is reduced, the peristalsis disappears or is disordered, while the upper esophagus and stomach can be normal, the duodenum and colon pressure measurement is also abnormal, the small intestine pressure can be measured, and the mechanical and pseudo-intestine can be distinguished more accurately. Obstruction and pathological type of pseudo-intestinal obstruction, avoid unnecessary laparotomy, and also as a prognostic indicator, a group of 60 children reported, small intestine pressure combined with X-ray examination, the results of 57 cases were correctly diagnosed, only 3 cases Exploratory laparotomy, 90% of children confirmed neuropathic pseudo-intestinal obstruction, 10% were myopathy obstruction.

Pressure measurement method: a 200 cm long polyethylene tube with a plurality of side holes at the front end and a side hole spacing of 10 cm. The fiber is placed under the guidance of a fiber enteroscope and placed at the end of the intestine, connected to a pressure transducer and a recorder, and slowly and continuously filled with water (O) .6ml/min), measuring the pressure, contraction activity and coordination of different parts of the small intestine cavity, the normal intestinal state of the small intestine pressure wave pattern is very regular, can be divided into four periods: the first phase, that is, the stationary phase, the small intestine Mild or no activity; phase 2, intermittent activity, medium amplitude contraction wave; phase 3, strong contraction wave and spread to the distal small intestine; stage 4, strong contraction and then back to phase 1 State, mechanical intestinal obstruction, manifested as low amplitude contraction wave, no peristaltic contraction after meal, pseudo-small intestinal obstruction has two abnormal pressure waves, myopathy is characterized by low frequency, low amplitude contraction wave, test meal After the emergence of many low-middle amplitude waves, and neuropathic patients showed multiple low-frequency, low-profile contraction waves, uncoordinated or lack of contraction waves after the test meal.

Radionuclide determination of gastric emptying and small intestine transit time using radionuclide labeled meal method can accurately determine gastric emptying and small intestine transit time, confirm the existence of abnormal gastrointestinal function and evaluate the results of drug treatment of pseudo-intestinal obstruction This method is less painful for the patient and can be repeated. Mayer measures the gastric emptying time of 11 patients with pseudo-intestinal obstruction with solid and liquid meals, and the results are prolonged. Therefore, the motor dysfunction of pseudo-intestinal obstruction is not limited to the small intestine. Also involved in the stomach, Camilleri measured with 131I labeled meal, found that patients with abnormal intestinal pressure measurement also have a small intestinal transit time, Nielsen with 99mTc labeled meal method confirmed small intestinal dysfunction in patients with small intestinal obstruction, Schang for a case of pseudo-intestinal obstruction The patient was measured with a 99mTc labeled meal before and after treatment with naloxone. As a result, gastric emptying and intestinal transit time were prolonged before treatment, and returned to normal after treatment.

Diagnosis and diagnosis of pseudo-intestinal obstruction

The diagnosis of this disease is more difficult, often after repeated laparotomy, the disease is not considered when the cause of mechanical intestinal obstruction is not considered. In the 3 cases reported by Daping Hospital of the Third Military Medical University, 4 cases were mistaken for mechanical intestinal obstruction before surgery. Should raise awareness of the disease.

Differential diagnosis

1. Mechanical intestinal obstruction: typical clinical manifestations of intestinal obstruction, early abdominal distension can be insignificant, X-ray examination shows that the flatulence is limited to part of the intestine above the obstruction, even if the late stage is complicated by intestinal narrowing and paralysis, the colon will not be full of flatulence.

2. Paralytic ileus: no paroxysmal colic, intestinal peristalsis weakened or disappeared, abdominal distension was significant, and more secondary to severe infection in the abdominal cavity, retroperitoneal hemorrhage, major abdominal surgery, etc., without dysphagia and urine Detention, etc., X-ray examination can show large, small intestines all inflated.

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