Pediatric Intussusception Surgery 

Intussusception, which is defined as the telescoping or invagination of a proximal portion of intestine (intussusceptum) into a more distal portion (intussuscipiens), is one of the most common causes of bowel obstruction in infants and toddlers.

Intussusception was first described by Barbette in 1674, and Wilson was the first to successfully treat it surgically in 1831. In 1876, Hirschsprung first reported the technique of hydrostatic reduction,^[1] and, after monitoring a series of 107 cases, reported a 35% mortality rate attributable to intussusception in 1905.

Intussusception is the telescoping or invagination of a proximal portion of intestine into a more distal portion (see the images below). Vascular compromise and subsequent bowel necrosis are the primary concerns with intussusception. Among patients who undergo operative reduction of intussusception, as many as 10% may require bowel resection.

Frequency

The incidence of intussusception is 1.5-4 cases per 1000 live births, with a male-to-female ratio of 3:2. The greatest incidence of idiopathic intussusception is in infants aged 9-24 months. A seasonal incidence has been described, with peaks in the spring, summer, and the middle of winter. These periods correspond to peaks in the occurrence of seasonal gastroenteritis and upper respiratory tract infections.

Intussusception is ileocolic (see the first image below) in 80% of cases but may also be ileoileal (see the second image below), colocolic, or ileoileocolic. Most infants and toddlers (95%) with the condition do not have an identifiable specific lead point. In these idiopathic cases, careful examination may reveal hypertrophied mural lymphoid tissues (Peyer patches), which are due to adenovirus or rotavirus infection. Intussusception has also been found to increase the risk of tonsillar disease (ie, chronic or acute tonsillitis) and tonsillectomy in children.^[2]

A specific lead point that draws the proximal intestine and its mesentery inward and propagates it distally through peristalsis is identified in only 5% of cases and is most commonly found in cases of ileoileal intussusception. Specific lead points are more commonly found in children older than 3 years and almost always in adults with intussusception. Meckel diverticulum (see the image below) is the most common lead point, followed by polyps, such as with Peutz-Jeghers syndrome, and intestinal duplications.^[3]

Other lead points described include lymphomas, lymphangiectasias,^[4] submucosal hemorrhage with Henoch-Schönlein purpura, trichobezoars with Rapunzel syndrome,^[5] caseating granulomas due to abdominal tuberculosis,^[6] hemangiomas, and lymphosarcomas.

Children with cystic fibrosis (CF) may present with intussusception due to inspissated meconium in the terminal ileum. While generally observed as a complication in older children with CF, neonatal intussusception with meconium plug syndrome associated with CF has been reported.

Postoperative jejunoileal or ileoileal intussusception, which has no specific lead point in most cases, accounts for approximately 1% of intussusceptions in children of all ages. When a lead point is present with postoperative intussusception, several cases have been reported after appendectomy with stump inversion.^[7] Other rare reported types of intussusception have included retrograde jejunojejunal intussusception following duodenal atresia repair^[8] and an ileoileal type resulting from blunt abdominal trauma.^[9]

Although the vast majority of intussusception cases are idiopathic, Oshio et al (2007) in Japan reported a familial anatomical tendency that may predispose to the condition in the face of viral infection. Of 554 families who had at furthest a third-degree relative with an idiopathic case of intussusception, the authors found an incidence of approximately 7%, or 1 per 14.2 cases. The family history may help in the workup, and further genetic testing may eventually identify the gene responsible for this predisposition.^[10]

Intussusception results in bowel obstruction, followed by congestion and edema with venous and lymphatic obstruction. This progresses to arterial obstruction and subsequent necrosis of the bowel. Ischemia and then necrosis results in fluid sequestration and bleeding from the GI tract. If untreated, the bowel may perforate, resulting in sepsis.

In 1941, Ladd and Gross described the deceivingly healthy appearance of infants with intussusception.^[11] One rarely finds intussusception in a child who is thin, undernourished, and poorly developed. This is evident in that babies with intussusception are usually well nourished and generally above-average in physical development. This fat and healthy appearance is apt to mislead the physician in the early hours of the patient’s illness. Thus, the first visit may leave the physician with the impression that the parent is overanxious, whereas a return visit the next day shows that the child is desperately ill.

Disorders characterized by bowel obstruction, colicky abdominal pain, blood in the stool, an intra-abdominal mass, or a combination of these should be considered in the differential diagnoses of intussusception. These include gastroenteritis, appendicitis, Meckel diverticulum, malrotation with midgut volvulus, or incarcerated hernia.

Most infants with intussusception have a history of intermittent severe cramping or colicky abdominal pain, occurring every 5-30 minutes. During these attacks, the infant screams and flexes at the waist, draws the legs up to the abdomen, and may appear pale. These episodes may last for only a few seconds and are separated by periods of calm normal appearance and activity. However, some infants become quite lethargic and somnolent between attacks. Early on, the infant may vomit undigested food. As attacks continue, emesis may turn bilious. Stool that appear normal in character early in the course of the illness eventually become dark red and mucoid (resembling currant jelly), a sign of intestinal ischemia and mucosal sloughing.

Ideally, the dramatic paroxysms described above would sufficiently alert the parents to seek medical attention early in the course of the illness. If this is the case, initial inspection may reveal a robust infant who appears healthy. Between attacks, the infant may appear somnolent or quite normal, and findings on examination of the abdomen may be unremarkable. During an attack or spasm, the infant suddenly appears startled or anxious and begins to scream. Upon initial inspection, the abdomen may appear scaphoid; during paroxysms, it may be rigid; and later in the course of the illness, it may become distended with signs of peritonitis. Careful palpation after an attack has subsided may reveal an ill-defined or sausage-shaped mass.

With early ileocolic intussusception, the mass is typically found in the right upper quadrant or abdomen. The right lower quadrant may seem empty upon examination, a finding known as the Dance sign. This mass may be difficult to locate in inconsolable infants because of abdominal rigidity from muscle straining. If episodes of cramping are witnessed, the careful examiner may auscultate peristaltic rushes in the area of the intussusception.

The rectal examination should commence with inspection of fecal material in the diaper. Normal-appearing stool should be tested for occult blood. The presence of mucoid or frankly bloody stool supports the diagnosis. Rarely, inspection of the anus reveals the prolapsed tip of the intussusception. A digital rectal examination should be performed routinely, looking for blood or a mass higher in the anal canal.

In lieu of concerns about rotavirus vaccine–associated intussusception, The Brighton Collaboration Intussusception Working Group established a clinical diagnosis using a mix of major and minor criteria. This stratification helps to devise a working model based on 3 levels of evidence to suggest definite, probable, and possible cases of intussusception.^[12]

Major criteria

1. Evidence of intestinal obstruction: This is a history of bile-stained emesis, along with abdominal distention or abnormal or absent bowel sounds.
2. Features of intestinal invagination: This includes at least one of the following: Abdominal mass, rectal mass, or rectal prolapse, as well as an abdominal radiograph, sonogram, or CT scan showing visible intussusceptum or a soft-tissue mass.
3. Evidence of intestinal vascular compromise or venous congestion: This manifests as rectal bleeding or “red currant jelly” stool or blood on rectal examination.

Minor criteria

Minor criteria include any of the following:

• Male infants younger than 1 year
• Abdominal pain
• Vomiting
• Lethargy
• Pallor
• Hypovolemic shock
• Abdominal radiograph showing nonspecific abnormality

Stratification based on evidence levels

• level 1 - Definite (any one of the below)

  • Surgical criteria - Invagination of intestine found during surgery
  • Radiological criteria - Gas or liquid contrast enema showing invagination or abdominal sonogram, with specific features proven to be reduced by enema on postreduction sonogram
  • Autopsy criteria - Invagination of the intestine
• level 2 – Probable (either of the below)

  • Two major criteria (see above)
  • One major criterion and 3 minor criteria (see above)
• level 3 - Possible

  • Four or more minor criteria (see above)

The relevancy of this definition has also been clinically tested in Switzerland, where it correctly identified 86 of 96 confirmed episodes, 82 of which met level 1 evidence. Regarding sensitivity in comparison to this level 1 evidence, the level 2 (probable) had 65%, while level 3 (possible) had only 30%.^[13]

One prospective study in 2011 by Weihmiller et al focused on establishing predictive clinical criteria to risk stratify patients while performing a workup for intussusception. The 3 strongest clinical predictors for high risk were: male (p = 0.007), older thanage 5 months (p = 0.04), and a report of lethargy (p = 0.001). If a patient is older than 5 months, then he or she may be considered low risk if the abdominal radiograph is negative and there is diarrhea with no bilious emesis.

This study also recommends plain abdominal radiographs for all patients suspected of having intussusception. An abnormal abdominal plain film had a p value of 0.0001. Their definitions for an abdominal radiograph were either negative, no intussusception suspected, or positive/possibly-positive for intussusception, which led to more testing using either ultrasonography or air enema.

Of note, this study identified 38 intussusceptions out of 310 pediatric patients and did not find abdominal pain, abdominal mass, or guaiac-positive stools to be significant.^[14] However, these clinical findings are classical for intussusception based on prior research; therefore, patients with these symptoms and signs should still raise clinical suspicion for intussusception.

Stable patients in whom the index of suspicion for intussusception is high but who do not have evidence of ischemic bowel, perforation, or sepsis may undergo immediate contrast enema for diagnosis and treatment of suspected intussusception.

Immediate surgery is indicated in unstable patients, in patients who have peritonitis, and in patients with bowel perforation during attempted enema reduction. Elevated temperature and WBC counts have also served as relative indicators for surgery. Patients requiring surgery must be aggressively resuscitated with fluids, and care must be taken to preserve body temperature preoperatively, intraoperatively, and postoperatively.

Intussusception is the telescoping or invagination of a proximal portion of intestine into a more distal portion. Intussusception may be ileoileal, colocolic, ileoileocolic, or ileocolic, which is most common (see the image below). The primary concern with intussusception is vascular compromise and subsequent bowel necrosis. In addition to bowel obstruction, edema with venous obstruction and eventual obstruction of arterial flow leads to ischemia and eventual full-thickness necrosis of the intussuscepted bowel and mesentery.

Contraindications to enema reduction include evidence of bowel perforation and peritonitis.