Intussusception is a segment of the intestine that becomes lodged in the lumen of the intestine to which it is attached and causes obstruction to the passage of the intestinal contents. Acute intussusception is common in clinical practice, while chronic intussusception is usually secondary. Acute intussusception is most often seen in infancy, with infants aged 4 to 10 months being the most common, and the incidence decreasing with age after 2 years. Intussusception can occur throughout the year, with the highest incidence in late spring and early summer, and may be related to upper respiratory tract infections and viral infections. The incidence of intussusception is high in China, accounting for the first place in infant intestinal obstruction.
Etiology
1.Acute intussusception
The etiology is not clear, and may be related to the following factors.
(1) dietary changes 4 to 10 months after birth, the period of adding complementary foods and increasing the amount of milk, is also the peak of intussusception. Since the infant’s intestine cannot immediately adapt to the stimulation of the changed food, it leads to intestinal dysfunction and causes intussusception.
(2) Ileal anatomical factors During infancy, the ileocecal part is mobile, the ileocecal flap is overly hypertrophied, the small intestinal mesentery is relatively long, and 90% of the ileal flap in infants is lip-like convex into the cecum, which is more than 1 cm long, coupled with the rich lymphoid tissue in this area, it is easy to cause congestion, edema and hypertrophy after being stimulated by inflammation or food, and intestinal peristalsis tends to push the ileocecal flap forward and pull the intestinal tube to form an intussusception.
(3) Viral infection A series of studies have reported that acute intussusception is related to adenovirus and rotavirus infection in the intestinal tract.
(4) Intestinal spasm and autonomic dysregulation Due to various food, inflammation, diarrhea, bacterial toxins, etc. stimulate the intestinal tract to produce spasm, so that the intestinal peristaltic function rhythm disorder or retroperistalsis and cause intestinal overturning.
(5) Genetic factors Some patients with intussusception have a family history of the disease.
(6) Congenital intestinal malformation and other organic diseases such as Meckel’s diverticulum, congenital intestinal duplication malformation, etc. can become the cause of acute intussusception.
2, chronic recurrent intussusception
Most commonly seen in older children and adults, the cause of its occurrence is often secondary to the presence of intestinal pneumatosis, intestinal organism lesions commonly include intestinal polyps, diverticula, repetitive malformations, purpura hematoma, tumors and tuberculosis.
Clinical manifestations
1, pediatric intussusception is divided into infant intussusception (within 1 year old) and children intussusception, the former is clinically common.
2, infant intussusception is mostly primary intussusception, clinical characteristics are as follows.
(1) paroxysmal crying: common in previously healthy and obese infants, suddenly appear paroxysmal regular crying, lasting about 10 to 20 minutes, accompanied by hand and foot fidgeting, pale, refusing to eat, abnormal pain performance, then there are 5 to 10 minutes or more of temporary quiet, so repeated. This kind of paroxysmal crying is consistent with the interval of intestinal peristalsis, as the intestinal peristalsis pushes the intestinal segment forward, the mesentery is stretched, and the sheath of intussusception produces strong contraction and intense pain. In the late stage of intussusception combined with intestinal necrosis and peritonitis, the child is depressed and unresponsive.
(2) Vomiting Initially, it is milk and milk lumps or other food, but later it turns into bile-like material, and after 1 to 2 days it turns into foul-smelling intestinal contents, which indicates the seriousness of the disease.
(3) Abdominal masses When the abdomen is examined in the interval between two cries, a salami-like mass with slight movement and light pressure pain can be palpated in the right upper abdomen under the liver, and the right lower abdomen generally has a feeling of emptiness, and the mass can move along the colon.
(4) Jam-like blood stool Infants with intussusception occur in more than 80% of the bloody stool, as the first symptom of consultation, mostly in 6 to 12 hours after the onset of blood stool, the early case can appear in 3 to 4 hours after the onset of thin mucus or jelly-like jam-colored blood stool, can be repeated after a few hours.
(5) Anal finger diagnosis has important clinical value. In some children who come to the clinic early, although there is no blood in the stool, mucus and blood can be found in the rectum through anal finger diagnosis, which is extremely valuable for the diagnosis of intestinal entrapment.
(6) The general condition varies according to the early and late consultation, except for pallor and restlessness in the early stage, the nutritional status is good. Late stage children may have dehydration, electrolyte disorders, mental depression, lethargy and unresponsiveness. When intestinal necrosis occurs, there are signs of peritonitis and toxic shock may appear.
Intussusception in children
The clinical symptoms of intussusception in children are atypical compared with those of intussusception in infants. The onset of intestinal necrosis is relatively late. Children also have paroxysmal abdominal pain, but the interval between episodes is longer than that of infants, and vomiting is less common. Only about 40% of children with intussusception have blood in the stool, and blood in the stool often appears only a few days after the intussusception, or only a little blood on the finger sleeve during anal examination. In children who are more cooperative, the abdomen is often palpable with a waxy mass. Rarely, severe dehydration and shock are present.
3.Examination
(1) Abdominal ultrasound
It is a common examination method, which can assist in clinical diagnosis through the characteristic images of intussusception. In the transverse section of intussusception, it shows “concentric circles” or “target ring” sign, and in the longitudinal section, it shows “sleeve” sign.
(2) Air enema
Before air enema, a full frontal and lateral fluoroscopic examination of the abdomen is performed to observe the intestinal inflation and distribution. After air injection, a dense soft tissue mass in a semicircular shape can be seen at the top of the sleeve, protruding into the colon, forming an obvious cup shadow at the front of the gas, and sometimes some gas can be seen entering the sheath to form different degrees of pincer shadows. Clear diagnosis can also be treated by repositioning with pressure.
4.Diagnosis
The diagnosis is confirmed when the child presents with paroxysmal crying and restlessness, vomiting, jam-like blood stool, and a salami-like mass is palpated on abdominal examination. However, in 10%-15% of the cases, there is a lack of typical manifestations of acute intussusception when the child comes to the hospital, or only one or two of the symptoms. At this time, we should carefully check whether the mass can be palpated in the abdomen, whether there is a feeling of emptiness in the right lower abdomen, and observe whether there is jam-like mucus stool on the finger sleeve by anal finger diagnosis, so as to further confirm the diagnosis. If necessary, do abdominal ultrasound and other auxiliary examinations to assist in the diagnosis.
5.Treatment
Pediatric acute intussusception is divided into two kinds of non-surgical therapy and surgical therapy. In the non-surgical therapy there are air enema, barium enema and B ultrasound under water pressure enema reset therapy, of which air enema reset has been widely used for a long time.
(1) Non-surgical treatment
Air enema reset intussusception: the use of automatic pressure control of the colon gas injection machine, anal insertion of Foley tube, anal injection of gas that is to see a variety of images of intussusception mass, gradually to the ileocecal retreat until completely disappeared, at this time can be heard gas over water, the central abdomen suddenly raised, visible mesh or round inflatable ileum, indicating that the intussusception has been reset. Air enema reset rate can reach more than 95%.
Complications of air enema reset: serious complications are colon perforation, fluoroscopy appears under the abdominal cavity “flash” phenomenon, that is, the air suddenly appears to fill the entire abdominal cavity, standing position to see the diaphragm free gas. No gas is expelled from the anus when the anal tube is removed. The child has difficulty breathing, rapid heartbeat, pale face, and sudden deterioration of the condition. The gas should be discharged from the abdominal cavity immediately by stabbing with a sterile needle in the middle of the glabella and umbilicus.
(2) Surgical treatment
The indications for surgical treatment are
(1) Intussusception by air-pressure enema and other non-surgical repositioning is unsuccessful.
(2) The onset of intestinal necrosis is more than 24 to 48 hours and is clinically suspected.
(3) Recurrent intussusception, especially in children.
(4) Adult intussusception.
Before surgery, dehydration and electrolyte disorders should be corrected, water fasting, gastrointestinal decompression, antipyretic, oxygenation, blood preparation and other measures should be used if necessary. General anesthesia is mostly used for tracheal intubation.
Smaller infants may be treated with a transverse epigastric incision, or with a mackintosh incision if the enema is known to reach the ileocecal region. After opening the abdomen, the intussusception mass is revealed and examined for intestinal necrosis. If there is no intestinal necrosis, intussusception is repaired along the colonic frame by compression and extrusion. After the reset of intussusception, the intestinal tube should be carefully examined for necrosis, rupture of the intestinal wall, and organic lesions of the intestinal tube itself, etc. If there are no such signs, the appendix should be removed, the intestinal tube should be incorporated into the abdominal cavity, and the abdominal wall should be sutured by layers. In cases where the intestine cannot be reset and necrosis is present, necrotic intestinal segment should be resected and anastomosed.