Purpose or Case Report: 1. To describe intussusception US aspect
2. To diagnose the different anatomic forms
3. To detect a leadpoint at the intussusceptum apex
4. To provide sonographic prognostic criteria
5. To recognize benign small bowel intussusception
6. To desmontrate US impact in the therapeutic management
Methods & Materials: 451 intussusceptions diagnosed with sonography over a 13-year period, were studied for US pattern, anatomic type, lead point at the intussusceptum apex, trapped fluid within the intussusceptum, associated small bowel occlusion, and treatment by sucessful therapeutic enema or surgery with information about bowel compromise and pathological findings.
Results: 1. Intussusception US features with anatomic correlation
2. Characteristic US findings in ileocolic, ileoileocolic, small bowel and colocolic types
3. US appearance of leadpoints: Meckel’s diverticulum, cystic duplication, Burkitt lymphoma, and polyp
4. Risk criteria: trapped fluid within the intussusceptum and small bowel obstruction. No risk criterion: absence of ischemia. Both criteria: high risk of bowel compromise increasing with fluid amount
5. Benign small bowel intussusceptions: very frequent, small, peristaltic, with thin layers, no leadpoint, no bowel obstruction and spontaneous reduction
6. Enema therapy: to reduce idiopathic ileo(ileo)colic and colocolic forms. US: to guide hydrostatic enema, to assess reduction or recurrence. Surgery: in cases with bowel compromise, with leadpoint and in pathological small bowel intussusception. Chemotherapy: to produce spontaneous reduction in proven disseminated Burkitt lymphoma.
Conclusions: US diagnosis of anatomic form, of risk criteria and of a leadpoint permits to guide therapeutic management. The idiopathic ileocolic intussusception due to lymphoid hyperplasia, by far the most common form, must almost always be reduced by enema. Surgery shoud be required only in cases with pathological leadpoint and/or with bowel compromise (almost exclusively in ileoileocolic form). In contrast, pathological small bowel intussusception is very rare, secondary or associated with a predisposing condition, produces small bowel occlusion and almost always requires surgery. Colocolic intussusception is exceptional, easily reduced by enema but it will recur if the leadpoint is not removed.