You are in: eMedicine Specialties > Radiology > PEDIATRICS Intussusception, ChildArticle Last Updated: Jul 2, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 9
  Author: Beverly P Wood, MD, MS, PhD, Professor, Departments of Radiology and Pediatrics, Division of Medical Education, Keck School of Medicine, University of Southern California Beverly P Wood is a member of the following medical societies: American Academy of Pediatrics, American Association for Women Radiologists, American College of Radiology, American Institute of Ultrasound in Medicine, American Medical Association, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America, and Society for Pediatric Radiology Editors: Lori Lee Barr, MD, FACR, Clinical Associate Professor of Radiology, Department of Radiology, University of Texas Health Science Center in San Antonio; Member, Board of Directors, Austin Radiological Association; Consulting Staff, Seton Health Network, Columbia/St David's Healthcare System, Healthsouth Rehabilitation Hospital of Austin and Georgetown Hospital; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; David A Stringer, BSc, MBBS, FRCR, FRCPC, Professor, National University of Singapore; Head, Diagnostic Imaging, KK Women's and Children's Hospital, Singapore; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; John Karani, MBBS, FRCR, Consulting Staff, Department of Radiology, King's College Hospital, London Author and Editor Disclosure Synonyms and related keywords: child intussusception, pediatric intussusception, ileocolic intussusception, ileoileal intussusception, colocolic intussusception INTRODUCTIONSection 2 of 9
  BackgroundIntussusception is a common cause of childhood intestinal obstruction. Some patients experience a seasonal form of intussusception, in which the disease occurs with a higher incidence in fall and spring; however, seasonal occurrence is not characteristic. Infants with intussusception often are well nourished, and the specific cause of the disease is unknown. Intussusception occurs more frequently in males than in females.1, 2 PathophysiologyInvagination of a bowel segment (usually, the small bowel) into the lumen of the more distal bowel (usually, the colon) occurs. The invaginated segment (intussusceptum) is carried distally by peristalsis. Mesentery and vessels become involved with the intraluminal loop and are squeezed within the engulfing segment (intussuscipiens). Almost all occurrences are acute. Venous congestion is a major factor both in symptomatology and in the characteristic presence of blood in the stool. Intussusception is known to occur with greater frequency in children who have undergone recent abdominal surgery, either intraperitoneal or retroperitoneal operations. It is thought that early adhesions or focal edema of the bowel wall create a lead point for the intussusception. Children with postoperative intussusception may present with unexplained bowel obstruction within a time frame that is unusual for the development of bowel obstruction in postoperative patients. FrequencyUnited StatesIn infants aged 6 months to 2 years, intussusception is not unusual and often follows an upper respiratory tract illness; however, inciting factors may be absent. Mortality/Morbidity
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AnatomyA loop of bowel infolds (and inverts) more distally into the lumen of the bowel and is then carried distally by peristalsis. Approximately 90% of intussusceptions are ileocolic. In ileocolic intussusception, the terminal ileum is carried through the ileocecal valve into the colon; it may reach the rectum. Idiopathic intussusceptions usually lack an identifiable lead point; they occur in children aged 6 months to 2 years. Lymphoid hyperplasia or hypertrophic lymph nodes have been postulated but not proven. Lead points in nonidiopathic intussusception may include the following:
Clinical DetailsMost intussusceptions are acute. The clinical picture is of a well-nourished infant with the following signs and symptoms of bowel obstruction:
The infant usually has one or more episodes of diarrhea mixed with blood and mucus (ie, currant-jelly stool), which is related to venous congestion. A palpable, slightly tender, sausage-shaped mass in the abdomen is characteristic. Although usually acute, chronic or recurrent intussusception may occur, with typical symptoms. In some patients, intussusception is painless; the infant may appear pale, diaphoretic, or lethargic. The physician may not suspect intussusception if unusual symptoms are present or if symptoms mask an upper respiratory infection (see Images 6-7).4 Preferred ExaminationIn some countries, history and physical findings are sufficient criteria for undertaking reduction procedures for intussusception.
Once the patient is stabilized, reduction procedures should be initiated immediately; radiographic examination and physical examination should be performed to ensure that neither free air nor peritonitis is present. It should be ascertained by physical examination that no peritonitis is present. Spontaneous reduction has been reported, but it is unusual (see Intervention). Surgical consultation should be sought early when intussusception is suspected. Despite positive results from reduction through the use of imaging techniques, reduction or re-intussusception may be unsuccessful, necessitating surgery. Surgeons should be made aware of the possible need for surgery. Rarely, complications from reduction with imaging techniques (perforation) require emergency surgery. Thus, alerting the surgical consultant is a prudent measure. The use of air, gas, or water-soluble contrast to reduce the intussusception decreases potential complications.5, 6 Limitations of TechniquesIntussusception may not be apparent on plain-film abdominal radiography. Radiographs may appear indeterminate or normal; therefore, the presence of an unremarkable abdominal radiograph should not be the basis for excluding a diagnosis of intussusception. US examination is almost always positive, although overlying loops of air-containing bowel may obscure intussusception (see Image 9). DIFFERENTIALSSection 3 of 9
Appendicitis Cecal Volvulus Other Problems To Be ConsideredInflammatory bowel disease
RADIOGRAPHSection 4 of 9
FindingsRadiographic findings may be normal. Usually, a pattern of small bowel obstruction with absence of gas in the right colon is visible. An intraluminal colonic filling defect may indicate intussusceptum. Intraluminal blood may create a speckled pattern of gas and colonic material. A careful search should be made for intraperitoneal free air; the presence of free air is a contraindication for reduction by enema because the presence of free air indicates that the bowel is already perforated (see Images 2, 4, 10). Degree of ConfidenceThe appearance of small bowel obstruction in conjunction with characteristic clinical findings almost always indicates intussusception, as does the appearance of a gasless cecum and/or an intraluminal bowel mass. Unless otherwise indicated, the diagnosis should be confirmed with an air or barium enema. False Positives/NegativesAppendicitis may have an "empty cecum" appearance that looks like intussusception. Inflammatory bowel disease may involve the cecum and appear like intussusception. Any abnormality that has an appearance like that of small bowel obstruction mimics intussusception, because findings often are nonspecific. Severe edema of the bowel wall as found in shigellosis, Salmonella infection, or enterohemorrhagic Escherichia coli infection may appear like intussusception. CT SCANSection 5 of 9
FindingsCT scanning is not normally indicated; however, if a lead point (eg, lymphoma) is suspected, CT scanning may be helpful. False Positives/NegativesVolvulus and some intraperitoneal masses (eg, cystic teratoma) mimic intussusception. ULTRASOUNDSection 6 of 9
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Degree of ConfidenceOn sonography, intussusception has a characteristic appearance; it is usually not mistaken for other bowel abnormalities.7, 8 INTERVENTIONSection 7 of 9
Unless perforation, peritonitis, or Henoch-Schönlein purpura is present, radiologic reduction should be attempted. The success rate is 50-85%, depending on factors such as the length of time of the intussusception and degree of edema of the loop and ileocecal valve. Reduction is still possible, although more difficult, in intussusceptions that have been in place for longer than 48 hours. In patients older than 2 years, it should be assumed that intussusception has a lead point etiology; in such cases, further investigation should be undertaken.9, 10, 11 Air reduction In the current method of air reduction, room air is introduced through a rectal catheter and is taped well in place. A manometer is attached to a Y-connector to monitor pressure in the colon. Pressure should never exceed 110 mm Hg. The air pressure on the intussusception usually forces the inverted bowel back through the ileocecal valve and into its proper position. When reduction occurs, the observed pressure falls precipitously. Contrast reduction Contrast reduction was widely used until the current decade. A large rectal tube is taped firmly in place, and dilute water-soluble contrast is introduced slowly by gravity drip into the rectum; hydrostatic pressure is used to reduce the intussusception. The fluid is placed a maximum of 3 feet above the level of the radiography table. No more than 3 attempts at reduction are undertaken, and the column is pressed against the intussusception mass no longer than 3 minutes at each attempt. Visualization of the small bowel usually indicates that intussusception has been reduced. The following rules need to be observed:
Reduction may proceed at an uneven rate, and it may slow at various locations; this is particularly true at the ileocecal valve, which is swollen and often resists passage of the intussusception (see Images 11-13). To ensure reduction, contrast should be observed entering the ileum. Once contrast enters the ileum, it often proceeds quickly through the ileum. Vomiting is a frequent side effect of reduction. The appendix usually fills before the ileum and should not be confused with the ileal reflux of contrast. If there is a problem with reduction across the ileocecal valve, the patient should be allowed to evacuate, and the ileum should then be refilled; this relaxes the valve and allows for better control on refilling. A swollen ileocecal valve may appear unreduced; therefore, identifying air or contrast material in the ileum is important (see Image 14). Recurrences Intussusception recurs in approximately 10% of children. Intussusception can recur at any time and is not a contraindication to repeat reduction. Sedation to assist reduction does not greatly affect the reduction rate. Glucagon has been advocated, but its efficacy has not been established. Medical/Legal Pitfalls
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MULTIMEDIASection 8 of 9
REFERENCESSection 9 of 9
Intussusception, Child excerpt Article Last Updated: Jul 2, 2008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
