Intussusception (medical disorder)
From Wikipedia, the free encyclopedia
| Intussusception Classification and external resources |
|
| ICD-10 | K38.8, K56.1 |
|---|---|
| ICD-9 | 543.9, 560.0 |
| OMIM | 147710 |
| DiseasesDB | 6913 |
| MedlinePlus | 000958 |
| eMedicine | emerg/385 |
An intussusception (a blockage of the intestine) is a medical condition in which a part of the small intestine that has invaginated into another section of intestine, similar to the way in which the parts of a collapsible telescope slide into one another.[1] The part which prolapses into the other is called the intussusceptum, and the part which receives it is called the intussuscipiens.
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[edit] Overview
The most frequent type of intussusception is one in which the ileum enters the cecum, however other types are known to occur, such as when a part of the ileum or jejunum prolapses into itself. Almost all intussusceptions occur with the intussusceptum having been located proximally to the intussuscipiens. The reason for this is that peristaltic action of the intestine pulls the proximal segment into the distal segment. There are, however, rare reports of the opposite being true.
It is diagnosed most often in infancy and early childhood, strikes about 2,000 infants (1 in every 1,900) in the United States in the first year of life. Its incidence begins to rise at about 2 to 3 months of life, peaks at 4 to 9 months of age, and then gradually declines at around 18 months. The condition often resolves by itself and is usually treated by use of an enema, but the blockage can require surgery. In the United States, intussusception is rarely fatal.The causes of intussusception have not been clearly established and are very poorly understood. They may include infections, anatomical factors and altered motility. Although infectious agents, including rotavirus, have been suspected by some researchers to be a possible causative factor, studies and analysis have not conclusively identified them to be such. A review of sparse data on the possible association between natural rotavirus and intussusception has not demonstrated a possible association until very recently. In addition, ecological studies revealed that no seasonality exists for intussusception in the United States, whereas rotavirus has distinct wintertime peaks. In developing countries, patterns of intussusception may be quite variable and different from developed countries. A likely reason for this may be incomplete reporting of cases in developing countries. Rates of intussusception may also vary according to socioeconomic status in developing country.
There have been suspicion[2] that it may be linked with certain childhood vaccinations due to improper use. The CDC through the Federal Government of the United States through the National Vaccine Injury Compensation Program provides compensation for individuals who suffer from injuries, if proven in court, of their reaction to vaccines that contain "live, oral, rhesus-based rotavirus."[3]
In February of 2006, a new rotavirus vaccination, called RotaTeq (Merck) or Rotarix (GlaxoSmithKline), was introduced after extensive testing and clinical trials. More than 60,000 doses of the vaccine were given to children before the vaccine was approved by the FDA, and of these 60,000 children, the number of cases of intusussception in children receiving the vaccine was no higher than would be naturally expected.
Intussusception occurs more frequently in boys than in girls, with a ratio of approximately 3:1.[4]
In adults, intussusception represents the cause of approximately 1% of bowel obstructions and is frequently associated with neoplasm, malignant or otherwise.[5]
[edit] Symptoms
Early symptoms can include nausea, vomiting, pulling legs to the chest area, and intermittent moderate to severe cramping abdominal pain. Later signs include rectal bleeding, often with red currant jelly stool (stool mixed with blood and mucus), and lethargy. Physical examination may reveal a sausage-shaped mass felt upon palpation of the abdomen.
In children or those too young to communicate their symptoms verbally, they may cry, draw their knees up to their chest or experience dyspnea with paroxsyms of pain.
Fever is not a symptom of intussusception. However, intussusception can cause a loop of bowel to become necrotic. This leads to perforation and sepsis, which causes fever.
[edit] Diagnosis
Intussusception is often suspected based on history and physical exam, including observation of Dance's sign. Per rectal examination is particularly helpful in children as part of the intussusceptum may be felt by the finger. A definite diagnosis often requires confirmation by diagnostic imaging modalities. Ultrasound is today considered the imaging modality of choice for diagnosis and exclusion of intussusception due to its high accuracy and lack of radiation. A target-like mass, usually around 3 cm in diameter, confirms the diagnosis. An x-ray of the abdomen may be indicated for evaluation of intestinal obstruction or the presence of free intraperitoneal gas; the latter finding would imply that bowel perforation has already occurred. In some institutions, air enema is used for diagnosis as the same procedure can be used for treatment.
[edit] Treatment
In the developed world the condition is not immediately life-threatening. The intussusception is usually treated with either a barium or water-soluble contrast enema or an air-contrast enema, which both confirms the diagnosis of intussusception, and in most cases successfully reduces it. The success rate is over 80%. However, approximately 5-10% of these recur within 24 hours.
If it cannot be reduced by an enema or if the intestine is damaged, then a surgical reduction is necessary. In a surgical reduction, the abdomen is opened and the part that has telescoped in is squeezed out(NOT pulled out) manually by the surgeon or if the surgeon is unable to successfully reduce it or the bowel is damaged, the affected section will be resected. More often, the intussusception can be reduced by laparoscopy, whereby the segments of intestine are pulled apart by forceps.
[edit] Prognosis
Intussusception may become a medical emergency if not treated early, as it will eventually cause death if not reduced. In developing countries where medical hospitals are not easily accessible, especially when the occurrence of intussusception is complicated with other problems, death becomes almost inevitable. When intussusception or any other severe medical problem is suspected, the person must be taken to a hospital immediately.
The outlook for intussusception is excellent when treated quickly, but when untreated it can lead to death within 2–5 days. Fast treatment is a necessity, because the longer the intestine segment is prolapsed the longer it goes without bloodflow, and the less effective a non-surgical reduction will be. Prolonged intussusception also increases the likelihood of bowel ischemia and necrosis, requiring surgical resection.
[edit] Footnotes
- ^ Gylys, Barbara A. and Mary Ellen Wedding, Medical Terminology Systems, F.A. Davis Company, 2005.
- ^ Murphy BR, Morens DM, Simonsen L et al: Reappraisal of the association of intussusception with the licensed live rotavirus vaccine challenges initial conclusions. JInfect Dis 2003;187:1301-1308
- ^ Vaccines: documented risks (2007). Retrieved on 2007-11-15.
- ^ Lonnie King, M.D., FACEP (2006). Pediatrics: Intussusception. Retrieved on 2006-06-05.
- ^ Gayer G, Zissin R, Apter S, Papa M, Hertz M (2002). "Pictorial review: adult intussusception--a CT diagnosis.". Br J Radiol 75 (890): 185-90. PMID 11893645. Free Full Text.
