Intussusception

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:

An intussusception is a situation in which a part of the intestine has prolapsed 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. 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.

Intussusception in humans is almost exclusively a disease of the young, usually those between 2 months and 36 months old. This may be a result of its link with certain childhood vaccinations. The CDC through the Federal Government of the United States through the National Vaccine Injury Compensation Program provides compensation for individuals who suffer intussusception as a result of their reaction to vaccines that contain “live, oral, rhesus-based rotavirus.”^[2]

Intussusception occurs more frequently in boys than in girls, with a ratio of approximately 3:1.

In adults, intussusception represents the cause of approximately 1% of bowel obstructions and is frequently associated with neoplasm, malignant or otherwise.^[3]

Intussusception was first mentioned in 1674 by Barbette of Amsterdam. It was described in detail in 1789 by John Hunter. He called it “introssusception” and described it as a rare form of bowel obstruction in adults, in which telescoping of an intestine segment occurs into another segment of intestine. In 1871, a case of intussusception in a child was operated upon by Sir Jonathan Hutchinson.

Intussusception may be classified into several subtypes based on location and etiology. According to location of intussusception it is classified into ileocolic, ileo-ileo-colic, jejuno-jejunal, jejuno-ileal, and colo-colic. According to etiology of intussusception it is classified into idiopathic or lead point (pathologic) types.

The exact pathogenesis of intussusception is not fully understood. Intussusception occurs if there is an imbalance between the longitudinal and radial smooth muscle forces of intestine that maintain its normal structure. This imbalance leads to a segment of intestine to invaginate into another segment and cause entero-enteral intussusception. Etiology of intussusception is either idiopathic or pathologic (lead point). In children intussusception occurs mostly due to idiopathic causes. Idiopathic causes include seasonal viral gastroenteritis, rotavirus vaccine, adenovirus infection, hypertrophy of intestinal peyers patches, and bacterial enteritis. In adults intussusception occurs mostly due a lead point. Lead point occurs due to Henoch-Schönlein purpura, cystic fibrosis, Celiac disease, Crohn’s disease, Meckel’s diverticulum etc.     

Common causes of intussusception in children can be divided into idiopathic and pathologic. Idiopathic causes include seasonal viral gastroenteritis, rotavirus vaccine, adenovirus infection, and bacterial enteritis. Pathologic causes of intussusception in children include Henoch-Schonlein purpura, cystic fibrosis, Celiac disease, Crohn’s disease, Meckel’s diverticulum, polyps, duplication cysts, and lymphoma. Intussusception in adults is mostly due to a pathologic lead point. Non-idiopathic intestinal causes for intussusception in adults can further be divided into benign and malignant enteric causes, and benign and malignant colonic causes.

Intussusception must be differentiated from other diseases that cause abdominal pain,nausea/vomiting,and rectal bleeding.

Intussuception is a common pediatric emergency. The incidence of intussusception is estimated to be 2000 cases in children born in USA in the first year of life. The prevalenceof intussusception does not vary with geographic and demographic distribution. Males are more commonly affected by intussusception than females. Male to female ratio is approximately 3:2. Intussusception most commonly affects children between the age of 6 months and 36 months. It can occur in adults but is mostly related to an underlying pathology (lead point).

Common risk factors for the development of intussusception include male gender, age 6 to 12 months and anatomical anomaly of the intestine. Less common risk factors in the development of intussusception include antecedent viral illness, seasonal variation, first generation Rotavirus vaccine, Meckel’s diverticulum, Celiac disease, polyp, cystic fibrosis, Henoch-Schönlein purpura (HSP), surgical procedures involving the gut, duplication cyst, lymphomas, and areas of reactive lymphoid hyperplasia.

There is insufficient evidence to recommend routine screening for intussusception.

If left untreated, patients with intussusception may progress to develop intestinal obstruction, perforation, and peritonitis . If intussusception is not treated then it can be fatal in 2-5 days.

Common complications of intussusception include: Intestinal perforation, intestinal Hernia, intestinal adhesions, peritonitis, intestinal necrosis, electrolyte imbalance, and recurrence.

Prognosis is generally excellent if diagnosed and treated early. After nonoperative reduction is less than 10%.Recurrence mostly occurs within 72 hours after first episode.In some cases recurrence has been reported after 36 months.More than 1 recurrence can be due to a lead point.After pneumatic enema recurrence rate is 4%.After barium enema recurrence rate is 10%.

A positive history of abdominal pain, vomiting, rectal bleeding, and lethargy is suggestive of intussusception. Presentation of intussusception is very variable. Suspicion for intussusception should be kept on a high index, especially in children aged 3 months – 5 years (Peak age of presentation). Obtaining history about different causes of symptoms like fever, exposure to toxins, and ill contacts. Common symptoms include pain, inconsolable crying, drawing up of legs,vomiting, abdominal mass, bloody stools, and current jelly stools. There can be intermittent pain free intervals in between episodes of pain.which can be confused with an episode of gastroenteritis. The classic triad of pain, sausage-shaped abdominal mass and currant jelly stool are only seen in 15% of initial patient presentation. Atypically patients might present with only abdominal pain and lethargy. Intussusception should be kept in mind in an infant presenting with lethargy or altered consciousness alone.

Patients with intussusception usually appear in distress . Physical examination of patients with intussusception is usually remarkable for Dance’s sign, sausage shaped palpable mass, and abdominal distension. On rectal examination the intussusceptum might be felt. Classical sign of intussusception – currant jelly stools may be present in a minority of cases at a later stage. Patient with intussusception usually appear chubby and healthy.

There are no diagnostic lab findings associated with intussusception. If due to intussusception gangrene develops then it may lead to leukocytosis. Dehydration and electrolyte may develop due to persistent vomiting and fluid sequestration because of obstructed bowel.

X-Ray findings:

An x-ray may be helpful in the diagnosis of intussusception. Plain xray abdomen of patient are done in supine and upright position. Findings on an x-ray suggestive of/diagnostic of intussusception include absence of air in right lower quadrant and right upper quadrant, soft tissue density in right upper quadrant in 25-60% of patients, and normal in 60% of cases.

Ultrasound findings:

An x-ray may be helpful in the diagnosis of Intussusception. Findings on an x-ray suggestive of/diagnostic of Intussusception include target sign or doughnut sign and pseudokidney sign. If the ultrasonographer is experienced then sensitivity, specificity and negative predictive value can be close to 100%.

CT findings:

CT scan may be helpful in the diagnosis of intussusception. CT scan maybe used when other image modalities like x-ray and ultrasound have not given positive results but suspicion of intussusception is high. CT scan is also used to characterize the pathology(lead point) once intussusception has been diagnosed by ultrasound. CT scan has its drawbacks in children as it is time consuming and leads to substantial radiation exposure.

Non-operative treatment of intussusception is done in patients who are stable and have normal vital signs with no signs of intestinal perforation. It is done in a clinical setting with an experienced physician. This is done to prevent a major complication called tension pneumoperitoneum. Methods include fluoroscopic and ultrasonographic guided hydrostatic or pneumatic enema. Ultrasound is preferred as it avoids exposure to ionizing radiation and has better detection of pathological lead points. Ultrasonographic reduction uses a saline enema as pneumatic enema cannot be used in this. If reduction is successful then the intussusception disappears and wate /air bubbles are seen in the terminal ileum. Fluoroscopic guidance is used if there is a filling defect within bowel enema. Both hydrostatic and pneumatic enema can be used under this method. If reduction is successful then free flowing contrast or air into the small bowel is seen and there is relief of symptoms. Complications of non-operative reduction include perforation of bowel.It mostly occurs in the distal part of intussusception in the transverse colon. Recurrence of intussusception can occur in about 10% children after successful reduction. 50% cases occur in the first 72 hours and all episodes of recurrence should be considered as the first episode.

Surgery is not the first-line treatment option for patients with intussusception. Surgery is usually reserved for patients with either unstable patient, intestinal perforation, peritonitis, a mass lesion and patients in whom medical therapy was completely unstable. Technique includes intravenous fluid resuscitation, N.G. tube decompression and use of laparoscopy. Benefits of laparoscopy include:- accurate diagnosis, rapid recovery and minimal use of narcotic analgesia post-operatively.

There are no established measures for the primary prevention of Intussusception.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sargun Singh Walia M.B.B.S.[2]

The exact pathogenesis of intussusception is not fully understood. Intussusception occurs if there is an imbalance between the longitudinal and radial smooth muscle forces of intestine that maintain its normal structure. This imbalance leads to a segment of intestine to invaginate into another segment and cause entero-enteral intussusception. Etiology of intussusception is either idiopathic or pathologic (lead point). In children intussusception occurs mostly due to idiopathic causes. Idiopathic causes include seasonal viral gastroenteritis, rotavirus vaccine, adenovirus infection, hypertrophy of intestinal peyers patches, and bacterial enteritis. In adults intussusception occurs mostly due a lead point. Lead point occurs due to Henoch-Schönlein purpura, cystic fibrosis, Celiac disease, Crohn’s disease, Meckel’s diverticulum etc.

• The exact pathogenesis of intussusception is not fully understood.
• Under normal conditions, a balance between the longitudinal and radial smooth muscle forces maintains the normal structure of intestine.
• Intussusception occurs if there is an imbalance between these forces.
• This imbalance leads to a segment of intestine to invaginate into another segment and cause entero-enteral intussusception.
• The proximal portion is called “intussusceptum” and the distal portion is called “intussuscipien”.
• If this telescoping of the intestine continues it can extend till the distal colon or sigmoid colon or even through the anus.
• Nitric Oxide Hypothesis^[1]
  • There is nitrergic innervation in the myentric plexus.
  • These receptors are in greater density at Ileocecal valve(ICV) than on terminal ileum and proximal large ileum. in younger age.
  • Nitric oxide(NO) acts on these receptors.
  • NO is a inhibitory neurotransmitter of the enteric nervous system. It acts by causing relaxation of smooth muscles.
  • Overproduction of nitric oxide (NO) occurs during inflammation.
  • This leads to relaxation of the ICV and causes altered intestinal motility.
  • This can lead to ileocecal intussusception.

• Intussusception is the most common abdominal emergency in children < 2 years of age.

• Uncommon in adults but when it occurs the most common cause is pathological due to lead point.

If the mesentery invaginates along with the intestine it may lead to lymphatic and venous congestion and cause intestinal edema. If not treated, it eventually leads to ischemia which further progress to peritonitis or even perforation.

• Idiopathic:- It is the most common cause of intussusception in children and accounts for about 75% of all cases. Any specific disease trigger point or lead point cannot be recognized. It can be further divided among various causes:
  • Viral causes
    • Seasonal viral gastro-enteritis.^[2]
    • Rotavirus Vaccine:- Intussusception is known to be caused by certain types of Rotavirus vaccines. An earlier iteration of the vaccine known as the Rotashield was taken out of the market because it was associated with an increased number of cases of intussusception. If there occurs any case of intussusception after vaccination with Rotavirus vaccine, then it should be reported to the Vaccine Adverse Event Reporting System (VAERS) by the providers.^[3]
    • Adenovirus:- There is a strong association with adenovirus infection. A case control study conducted in Vietnam and Australia shows that Specie C of adenovirus is a strong predictor of intussusception in children.^[4]
    • Viral infections stimulate the lymphatic tissue in the intestine and lead to the hypertrophy of the Peyers patches in the terminal ileum and cause the formation of a lead point. This may act as an obstruction and lead to intussusception. Due to this association with hyperplasia, use of glucocorticoids may be used to prevent recurrence but it is not encouraged.
  • Bacterial enteritis:- A retrospective cohort study done in children aged 0-5 years shows a strong association between bacterial enteritis and intussusception.^[5] There is an increased risk of development of intussusception with Shigella, Salmonella, E. coli and Campylobacter infections.
• Lead Point:- Lead point can be defined as any lesion that gets trapped in the intestine by peristaltic forces, which then gets dragged into the distal segment of the intestine leading to the formation of intussusception. Lead point accounts for 25% cases of iintussusception in childhood and almost 95% of cases of intussusception seen in adults. Lead point can be caused due to various pathological reasons which are as follows:
  • Henoch-Schönlein purpura (HSP):- It is is an IgA mediated inflammatory disorder which causes inflammation and bleeding of the small blood vessels in skin, intestine, joints, and kidneys. HSP is most commonly seen in children less than 7 years of age. In HSP, hematoma formation in the small intestine may act as a lead point. Intussusception mostly occur once the abdominal pain subsides.^[6][7]. Intussusception in HSP mostly originates in the ileum or jejunum , and more than one-half of cases are confined to the small bowel. In contrast to idiopathic intussusception, where the majority (80%-90%) are ileo-colic.
  • Cystic Fibrosis:- Intussusception is one of the complication of cystic fibrosis. In this thick inspissated/impacted stool acts as a lead point.^[8][9][10]
  • Celiac disease:- Recent studies show that celiac disease is associated with increased risk of intussusception. Celiac disease may lead to small bowel intussusception by causing dysmotility and excessive secretions in bowel wall or by causing small bowel weakness.^[11][12][13]
  • Crohns disease:- Crohns disease is a chronic granulomatous inflammatory disease which may lead to intussusception due to inflammation and stricture formation in the intestine. ^[14][15]
  • Meckel’s diverticulum
  • Polyp
  • Duplication Cyst
  • Lymphomas
  • Areas of reactive lymphoid hyperplasia
• Post-operative :- Small bowel intussusception can occur in postoperative cases. Most commonly seen are jejuno- jejunal or ileo-ileal cases. Most cases are seen after open procedures but can also be seen after non abdominal procedures. It can occur due to uncoordinated peristaltic activity and/or traction from sutures or devices such as a gastrojejunal feeding tube.^{[16][17][18][19]}

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