Congenital small bowel atresia and intestinal stricture
Introduction
Introduction to congenital intestinal atresia and intestinal stenosis Empty and ileal atresia are important causes of neonatal intestinal obstruction. The traditional concept regards jejunal atresia and ileal atresia as the same disease. Heij (1990) proposed that jejunal atresia and ileal atresia are two independent diseases. He has performed a comparative analysis of a group of jejunal atresia and ileal atresia, and found that there is a significant difference between the two. Patients with jejunal atresia have low birth weight or are premature infants, and more than half are multiple atresia or Apple-Peel atresia. Jejunal atresia has a more obvious genetic predisposition. Double-oval twins or the same family members have more patients, and other malformations are higher than ileal atresia. After jejunal atresia, the hospital stay is long and the mortality rate is also high. Therefore, the relationship between the two needs further confirmation. basic knowledge The proportion of illness: 0.002% Susceptible people: young children Mode of infection: non-infectious Complications: edema, hand and foot palsy
Cause
Congenital intestinal atresia and intestinal stenosis
(1) Causes of the disease
There is no theory that can satisfactorily explain the causes of small intestine atresia. After the 1950s, many scholars proposed several causes of fetal small intestine atresia through animal experiments and clinical studies.
1. Fetal intestinal damage and mesenteric vascular accident
After Louw and Bamal (1955) successfully made the small intestine atresia model with fetal dogs, a large number of experimental studies have shown that any cause of fetal intestinal damage and mesenteric vascular ischemia can lead to intestinal atresia and intestinal stenosis, Courtosis, Santulli and Evans It was confirmed that the fetus had intestinal torsion, intussusception, internal hemorrhoids and perforation, and various types of intestinal atresia were formed. Bland and Sutton pointed out that the fetal umbilical ring contracted too fast, and the compression of the midgut also developed intestinal atresia and stenosis. Seashore (1987) It is reported that 54% of the apple-Peel atresia coexisted with poor intestinal rotation. In these cases, the midgut was reversed in the uterus, and the superior mesenteric artery was embolized to form an apple-like atresia. Domestic Wu Rongde, Li Weixing and others reported intrauterine intussusception. Intestinal atresia, intraoperative or resected specimens were found in the intestines with residual intestines in the atresia, or intussusception and intestinal atresia. Recently, Bowen et al. used bipolar electrocoagulation needles to iron chicken embryonic intestinal vessels. Intestinal atresia in type I and type II chickens, all of which demonstrate that any cause of intestinal ischemia in the embryo or fetus is the cause of intestinal atresia.
2. Familial genetic factors
Lewis (1953) reported that a single egg had a type I ileal atresia, and Blyth and Dickon (1960) reported that 8 of the two families had Apple-Peel atresia, and continued to report the same. Many scholars believe that Apple -Peel atresia and multiple atresia are autosomal recessive hereditary diseases, and Nishikawa (1985) also reported that one case of other malformed Apple-Peel atresia was associated with chromosome 13 long arm deletion (13q-), although The genetics are not fully understood, but the obvious genetic predisposition of this disease has received widespread attention.
3. Superior mesenteric artery dysplasia
Jimenez and Reiner had an arterial angiogram of the apple-Peel atresia in the patient. The superior mesenteric artery was found to be abnormal. The starting point of the superior mesenteric artery was normal. After the start, the transverse mesenteric membrane was inserted and the mesenteric margin of the ascending colon was retrograde to the proximal end. The jejunum, which may be due to the primary absence of the mesorectum, causes the superior mesenteric artery to lose its supporting structure, resulting in the development of this artery, especially the small intestine artery branch, which forms a type of atresia. Other authors have also found mesenteric in the intestinal atresia specimen. Report of vascular branch malformation.
4. Embryonic intestinal cavitation disorder
Some scholars believe that the upper esophagus, duodenum, upper jejunum and colon atresia and stenosis are caused by incomplete airway in the embryonic stage. Jiang Zexi reports that in the histological observation of jejunal atresia specimens, the intestine is filled with epithelium and Mucosa, so that the intestinal lumen is occluded or only the cavity is left. Some intestinal mucosa is characterized by multiple cavitation membranous septa, such as bamboo joints, and some exhibit a bridge-like connection between the mucosa and the submucosal tissue. These pathological forms demonstrate that the obstruction of the intestinal cavitation process leads to atresia.
(two) pathogenesis
Pathological typing
Empty, ileal atresia is mostly single, the incidence of multiple atresia varies from 6% to 32%, and the pathological type is mostly modified by Grosfeld.
Blocking type I: diaphragm is blocked, the intestine is blocked by a diaphragm, the intestine and mesangium are kept continuous, and the center of the diaphragm can have pinhole-sized pores (very few small holes are located at the edge of the diaphragm).
Blocking type II: blind end lock, the intestines at both ends of the lock are blind pockets, with cords connected at both ends, the mesentery maintains continuity, the cord is generally several centimeters long, and there are also up to 40cm.
Atresia type IIIa: blind end occlusion, mesenteric separation, blind pockets at both ends of the occlusion, V-shaped defects in the mesentery between the two blind ends.
Atresia type IIIb: apple skin-like atresia (Apple-Peel atresia), the atresia is located at the proximal end of the jejunum, the two blind ends of the atresia are separated, the superior mesenteric artery is abnormally developed, only the first jejunum branch and the right colon artery remain, and the ileal artery becomes blocked. The distal small intestine is the only nutrient vessel. The small intestine is free. The small intestine is surrounded by a vascular branch like a string of peeled apple peel. Due to the lack of mesenteric fixation, it is prone to intestinal torsion. The length of the small intestine is obviously shortened, and even the short intestine is formed. Sign.
Atresia type IV: multiple atresia, multiple intussusception in the small intestine, can be I, II, IIIa coexist at the same time, the number of locked parts is different, small intestine and colon at the same time there are multiple atresia is rare.
Type I and type II are the most common types of small intestine atresia, accounting for 58% to 65% of the total.
2. Pathological changes
(1) ileal atresia: the length of intestinal intestine is significantly shorter than that of normal newborns, with an average of 100-150 cm, and normal newborns are 250-300 cm. The proximal intestinal tube is expanded and expanded, and the diameter can reach 4-6 cm. Hypertrophy, peristaltic dysfunction, severe intestinal wall thinning, blood circulation disorder, necrosis or perforation, meconium peritonitis, small distal intestine and colon collapse, diameter of only about 0.5cm, intestinal cavity does not contain gas and Meconium, only a small amount of mucosal secretions without bile, in some cases, intestinal atresia occurs in the late pregnancy, the distal mesenteric cavity contains normal meconium, so meconium can be excreted after birth. In the case of full-term ileal atresia, the colon morphology is often close to normal, and the cause of atresia is mostly intrauterine intussusception.
Histological examination showed that the layers of the proximal intestinal wall were thickened and the proportion was imbalanced. The intestinal wall was thin, necrotic or perforated, and the distal intestinal wall was thicker than the normal intestinal tube, but not as close to the proximal intestinal wall. The number of ganglion cells in the myenteric plexus of the end-intestinal tract was significantly reduced, nuclear deviation, deep staining, membranous septum or bridge connection with cavitation in the lumen of the jejunum atresia, necrosis in the ileal atresia Intestinal wall structure, circular cell infiltration in the mesentery, indicating mesangial vascular accident, blood supply disorder leading to atresia, and meconium peritonitis, inflammatory cell infiltration and calcification in all layers of the intestinal wall and mesentery .
(2) intestinal stenosis: mostly valvular stenosis, the degree of stenosis is different, the small in the center of the valve only 2 ~ 3mm diameter of the small hole, the larger part of the small intestine tube slightly narrow ring.
Some cases have meconium peritonitis at the same time. In addition to the above pathological changes, there are extensive intestinal adhesions and calcified meconium. In addition, some are accompanied by other congenital malformations: such as severe jaundice, biliary atresia, esophageal atresia, Intestinal perforation, umbilical bulging, anorectal atresia, Merkel diverticulum, intestinal duplication and other gastrointestinal malformations, multiple fingers (toes), hypospadias, horseshoe kidney and other urinary malformations, and cardiovascular diseases such as congenital heart disease Malformation, small intestine atresia accompanied by congenital stupid type is rare.
Prevention
Congenital intestinal atresia and prevention of intestinal stenosis
1, early pregnancy, avoid fever and cold. Women who have had high fever in early pregnancy, even if the child does not have obvious appearance deformity, brain tissue development may be adversely affected, manifested as mental retardation, poor learning and reaction ability, this mental retardation can not be restored. Of course, fetal fever caused by high fever is also related to the sensitivity of pregnant women to high fever and other factors.
2. Avoid getting close to dogs and cats. Few people know that cats with bacteria are also a source of infectious diseases that are a great threat to fetal malformation, and cat feces are the main route of transmission of this malignant infectious disease.
3. Avoid women who wear makeup every day. The survey shows that the incidence of fetal malformations in heavy makeup is less than 1.25 times that of heavy makeup. The main adverse effects on fetal malformation are arsenic, lead, mercury and other toxic substances contained in cosmetics, which affect the normal development of the fetus. Secondly, some of the ingredients in the cosmetics are exposed to ultraviolet rays in the sun to produce teratogenic aromatic amine compounds.
4, to avoid mental stress during pregnancy. Human emotions are controlled by the central nervous system and the endocrine system. One of the endocrine corticosteroids is closely related to human mood changes. When pregnant women are emotionally stressed, adrenocortical hormone may block the fusion of a certain tissue of the embryo. If it occurs during the first 3 months of pregnancy, it will cause malformations such as cleft lip or palate.
5. Avoid drinking alcohol. Pregnant women drink alcohol, alcohol can enter the developmental embryo through the placenta, causing serious damage to the fetus. Such as a small head, very small ear and nose and a wide upper lip.
6, avoid eating mold and vegetarian food. Experts pointed out that if pregnant women eat food contaminated with mycotoxin (mildew food), mycotoxins can cause fetal chromosome breaks in the fetus through the placenta. The prognosis of intestinal atresia is related to the position of atresia, and the survival rate of simple atresia, distal jejunum and proximal ileum is high. In recent years, the mortality rate of intestinal atresia has decreased significantly. The domestic survival rate is 51.3%~73.3%, and the foreign country is about 70%-85%. Low birth weight, with other malformations, has a lower survival rate.
Complication
Congenital intestinal atresia and complications of intestinal stricture Complications, edema, hand and foot palsy
Can be caused by pneumoperitoneum, so that abdominal distension is more obvious, abdominal wall edema, redness and brightening, abdominal wall venous engorgement, bowel sounds disappear; and there are breathing difficulties, cyanosis, body temperature does not rise and systemic poisoning symptoms.
Symptom
Congenital intestinal atresia and intestinal stenosis symptoms Common symptoms Abdominal distension Dehydration constipation Abdominal wall venous engorgement Intestinal perforation Edema Inability to breathe Intestinal atresia
The clinical manifestations of congenital intestinal atresia or intestinal stenosis are mainly symptoms of intestinal obstruction, and the morning and evening and severity of symptoms depend on the location and extent of obstruction. Intestinal atresia is complete intestinal obstruction. The main symptoms are vomiting, bloating and Constipation, vomiting occurs more than after the first feeding or on the first day after birth. The morning and evening appear to be related to the atresia. The duodenum and high intestinal atresia occur frequently and frequently, while the ileum, colon and other low-level atresia. It can occur 2 to 3 days after birth. After vomiting, it is progressively aggravated, and the amount of vomiting is high. The vomit of high intestinal occlusion is milk, mostly bile, sometimes old blood, and vomiting after milk. A small number of duodenum occurs above the common bile duct opening, there is no bile in the vomit, and low locus vomit can be fecal-like and smelly.
Abdominal distension is a common sign of intestinal atresia. The degree of abdominal distension is related to the position of the atresia and the time of treatment. The higher the position of the general atresia, the earlier the diagnosis time, the lighter the degree of abdominal distension, and vice versa, the more severe the case of high atresia, the abdominal distension only Limited to the upper abdomen, more or less serious, after a large amount of vomiting or stomach tube to withdraw the stomach content, abdominal distension can be disappeared or significantly reduced, low-level atresia cases, the whole abdomen showed a consistent expansion, progressive aggravation, a large amount of vomiting or withdrawal of stomach content After that, there was no significant change in bloating. Occasionally, gastric or gastric peristaltic waves were seen in the upper abdomen during high intestinal atresia, and dilated intestinal fistula was often seen in low intestinal atresia.
The absence of normal fetus discharge after birth is an important manifestation of intestinal atresia. Normal neonates discharge normal meconium within 24 hours after birth, which is dark green, except for secretions and intestinal mucosa of stomach, intestine, liver and pancreas. Outside the exfoliated cells, there are still amniotic fluid swallowed by the fetus and keratinized cells of their own skin. The children with intestinal atresia are excreted without meconium after birth, and some only discharge a small amount of grayish white or blue-gray mucus, which is the distal part of the lock. Intestinal secretions and exfoliated cells are different from normal meconium. It has been reported that a small number of meconium may be excreted in individual sick children.
In the first few hours after birth, the overall condition of the sick child is no different from that of the normal child, but soon it is manifested as restlessness, can not fall asleep, does not eat milk or sucking weakness, due to frequent vomiting, dehydration and poisoning quickly occur, and Often accompanied by aspiration pneumonia, the systemic condition deteriorates rapidly, such as intestinal perforation peritonitis, due to the occurrence of pneumoperitoneum, making abdominal distension more obvious, abdominal wall edema, redness and brightening, abdominal wall venous engorgement, bowel sounds disappear; Difficulty breathing, cyanosis, body temperature does not rise and symptoms of systemic poisoning.
The clinical symptoms of intestinal stenosis vary depending on the degree of stenosis. A few cases with significant stenosis have complete intestinal obstruction after birth, which is difficult to distinguish from intestinal atresia. Most of them have incomplete intestinal obstruction after birth. The clinical manifestations are repeated vomiting. The vomit is milk and bile. The meconium is excreted after birth, but the amount is less than normal. The degree of bloating depends on the stenosis: high stenosis is limited to the upper abdomen; lower stenosis is Total abdominal distension, because it is chronic incomplete intestinal obstruction, intestinal type and intestinal peristalsis are often seen in the abdomen, and bowel sounds are hyperthyroidism.
Intestinal atresia is 15.8%45% with amniotic fluid, especially jejunal atresia, amniotic fluid can exceed 20002500ml, mother has excessive amniotic fluid, infants have persistent vomiting after birth, progressive bloating and no Normal meconium discharge, that is, the possibility of intestinal atresia should be suspected. If you do an anal examination or if you still have no meconium excretion with 0.9% saline enema, you can exclude meconium constipation and congenital giant caused by meconium thickening. The colon is very important.
Examine
Congenital intestinal atresia and intestinal stricture examination
The alpha-fetoprotein content in the mother serum or amniotic fluid is increased, and the karyotype variation of the fetal blood karyotype suggests that the fetus may have intestinal malformations.
1. X-ray abdominal plain film
It is of great value in the diagnosis of intestinal atresia and intestinal stenosis. High jejunum atresia Abdominal upright flat film shows "three bubble sign"; or upper stomach a large liquid level and 3 to 4 expanded jejun small liquid level; no gas shadow in the lower abdomen. Low intestinal atresia shows more dilated intestinal fistula and has a large fluid level. Except for the extreme expansion of the most intestines, the caliber of other dilated intestinal fistulas is mostly uniform, and there is no gas in the colon and rectum on the lateral radiograph, which is different from paralytic intestinal obstruction.
It is not appropriate to have a barium meal examination for children with intestinal atresia because of the risk of causing aspiration pneumonia. However, for clinically atypical cases, it is necessary to perform barium enema examination. It is not only possible to determine the diagnosis of intestinal atresia according to the fetal colon, to determine whether the colon is locked, but also to exclude congenital megacolon or intestinal malrotation.
Cases of intestinal stenosis often require barium meal examinations to make the diagnosis clear. Under fluoroscopy, it can be seen that the expectorant accumulates in the obstruction site, and only a small amount of expectorant enters the distal intestinal lumen through the narrow segment.
2. Prenatal B-ultrasound
Ultrasound before the B-mode ultrasound scan is very valuable for the diagnosis of fetal small intestine atresia. High jejunal atresia shows an elongated fluid zone extending from the stomach to the proximal end of the jejunum or several expanded jejunal fluid zones in the upper part of the fetal peritoneal cavity.
In the past, many people especially emphasized the Farber test, which has keratinized epithelial cells in the baby's fetus, which is important for the diagnosis of intestinal atresia. In recent years, it has rarely been used clinically, because it is generally not difficult to determine the diagnosis of intestinal atresia based on clinical and X-ray examination. In addition, the test is not completely accurate.
Diagnosis
Diagnosis and diagnosis of congenital intestinal atresia and intestinal stenosis
According to the clinical manifestations, the examination can be diagnosed.
