US features of transient small bowel intussusception in pediatric patients.

OBJECTIVE: To describe the sonographic (US) and clinical features of spontaneously reduced small bowel intussusception, and to discuss the management options for small bowel intussusception based on US findings with clinical correlation.

MATERIALS AND METHODS: During a five years of period, 34 small bowel intussusceptions were diagnosed on US in 32 infants and children. The clinical presentations and imaging findings of the patients were reviewed.

RESULTS: The clinical presentations included abdominal pain or irritability (n = 25), vomiting (n = 5), diarrhea (n = 3), bloody stool (n = 1), and abdominal distension (n = 1), in combination or alone. US showed multi-layered round masses of small (mean, 1.5+/-0.3 cm) diameters and with thin (mean, 3.5+/-1 mm) outer rims along the course of the small bowel. The mean length was 1.8+/-0.5 cm and peristalsis was seen on the video records. There were no visible lead points. The vascular flow signal appeared on color Doppler images in all 21 patients examined. Spontaneous reduction was confirmed by combinations of US (n = 28), small bowel series (n = 6), CT scan (n = 3), and surgical exploration (n = 2). All patients discharged with improved condition.

CONCLUSION: Typical US findings of the transient small bowel intussusception included 1) small size without wall swelling, 2) short segment, 3) preserved wall motion, and 4) absence of the lead point. Conservative management with US monitoring rather than an immediate operation is recommended for those patient with typical transient small bowel intussusceptions. Atypical US findings or clinical deterioration of the patient with persistent intussusception warrant surgical exploration.