INTUSSUSCEPTION

Although intussusception can occur at any age, the greatest incidence occurs in infants between 4-10
months of age. Over half of the cases are in the first year of life. Frequently occurs after a recent upper
respiratory infection, by Adenovirus type 3 that causes a reactive lymphoid hyperplasia that act as lead point (of Peyer's patch). A definite lead point is identified in about 5% of patients. These include: Meckel's diverticulum, polyps, Henoch's Schönlein purpura, hematoma, lymphoma, foreign bodies, and duplications. Most children have no lead point and it is felt that enlarged mesenteric nodes or swollen Peyer's patches may be the cause. The baby has intermittent periods of severe discomfort with screaming, stiffening and drawing up of the legs, followed by periods of rest. Vomiting may occur and bloody, mucoid (currant jelly) stool may be passed. The baby may become dehydrated and appear acutely ill. Frequently, lethargy may be an early sign. The diagnosis is made by barium enema, and hydrostatic reduction of the intussusception with barium is successful in approximately 50% of cases. To be successful, the barium must reflux into the terminal ileum. The surgeon should be notified before an attempt at barium reduction, and should be present at the time of study.

Recently the use of gas enema reduction has been successful in patients with: (1) symptoms less than 12 hours, (2) no rectal bleeding, (3) absence of small bowel obstruction, and (4) normally hydrated. Ultrasonography can be used as a rapid sensitive screening procedure in the initial diagnosis of intussusception. Previous adverse clinical features that precluded barium reduction can be replaced during gas reduction.

Predictors of failure of reduction are: (1) ileocolic intussusception, (2) long duration of symptoms, (3) rectal bleeding, and (4) failed reduction at another institution. Air reduction (pneumocolon) is a very effective alternative method since it brings less radiation (shorter fluoroscopy time), less costs and less morbidity in cases of perforations.

Failure of hydrostatic reduction requires urgent operation through a right lower quadrant horizontal
incision. The intussusception is reduced by pushing on the distal bowel like a tube of toothpaste rather than pulling the proximal bowel. Most cases are ileo-colic intussusception, and a few are jejuno-jejunal or ileo-ileal intussusception.