Ninety percent of intussusceptions in children are idiopathic with peak incidence occurring between 5 and 9 months.
Meckel diverticulum is most common “pathologic” lead point.
Triad of abdominal pain, palpable abdominal mass, and currant jelly stool is present in fewer than 50% of cases.
Ultrasound is excellent for confirming diagnosis.
Eighty-five percent successfully reduced nonoperatively with the use of fluoroscopically guided air enema.
Laparoscopic approach to operative reduction is effective and shortens length of stay.
Etiology and Pathophysiology
Intussusception occurs when a segment of intestine invaginates or “telescopes” into the adjacent distal bowel. Although the process can occur anywhere in the intestine, 90% of the cases in children are ileocolic (Fig. 45-1) in location. The invaginating proximal bowel is termed the intussusceptum and the receiving distal bowel segment the intussuscipiens. Intussusception can occur at any age; however, it is unusual in children younger than 3 months or older than 3 years. The peak incidence occurs between 5 and 9 months.
Ileocolic intussusception showing how the mesenteric vessels are compressed and squeezed between the layers of the intussusceptum. Resultant edema exacerbates venous congestion leading to ischemia in the intussusceptum. Untreated, tissue pressure will exceed arterial pressure and result in necrosis.
The majority of cases (90%) of intussusception in children are idiopathic. In these patients, viral-induced lymphoid hyperplasia has been hypothesized to account for the “lead point.” Adenovirus, rotavirus, and human herpes virus 6 have all been implicated as potential causative agents.
Ten percent of children with intussusception will have an identifiable cause or “pathologic” lead point, most commonly a Meckel diverticulum. Other identifiable lead points include lymphoma and intestinal polyps (Fig. 45-2), conditions most frequently seen in older children. Certain systemic conditions can also predispose children to develop intussusception. For example, intussusception is the most common surgical complication seen in patients with Henoch–Schonlein purpura. Patients with cystic fibrosis, familial polyposis, nephrotic syndrome, and Peutz–Jeghers syndrome are also predisposed to developing intussusception.
Small bowel intussusception caused by polyp (the second commonest pathogenic lead point).
Aggressive diagnostic workup to identify a pathologic lead point should be initiated when an intussusception is not ileocolic in location or when an intussusception occurs at an age outside the typical infant idiopathic range.
Severe intermittent cramping abdominal pain occurring at intervals every 15 to 20 minutes in an infant or toddler is a hallmark of intussusception and is noted in up to 95% of children with this diagnosis. The child's abdomen is generally soft and the child may seem relatively playful and well between episodes of colic. Abdominal colic is so prevalent with intussusception that its ...