Ultrasound features of intussusception predicting outcome of air enema.
OBJECTIVE
To examine features identified on US which predict success or failure of air-enema reduction of intussusception.


METHODS
A retrospective study of 117 consecutive episodes of intussusception, presenting for US over a 6-year period. The specific features examined were: free fluid within the peritoneum, small-bowel obstruction, colonic wall thickness, and fluid trapped between the colon and the intussusceptum.


RESULTS
The overall reduction rate, irrespective of US features, over the 6-year period was 72 %. Reduction rates were significantly higher with the absence of free fluid, trapped fluid, or small-bowel obstruction (93 %). The presence of trapped fluid predicted an unfavourable outcome, with a significantly lower success rate (25 %). Colonic wall thickness did not predict outcome; in successful reductions, mean wall thickness was 7.2 mm and in failed reductions 7.6 mm.


CONCLUSIONS
Where free fluid, small-bowel obstruction, and trapped fluid are absent, almost 100 % success with air-enema reduction should be achievable. Where trapped fluid is present, air enema should be performed cautiously to avoid perforation caused by overvigorous attempts at pneumatic reduction of an incarcerated intussusception.
Britton
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I
Department of Radiology, Royal Hospital for Sick Children, Yorkhill, Glasgow, UK.
Wilkinson
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AG
D000388:Air; D001202:Ascitic Fluid / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D003106:Colon / Q000000981:diagnostic imaging; D003108:Colonic Diseases / Q000000981:diagnostic imaging* / Q000628:therapy; D004733:Enema / Q000379:methods*; D005122:Exudates and Transudates; D005260:Female; D006801:Humans; D007223:Infant; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging; D007421:Intestine, Small / Q000000981:diagnostic imaging; D007443:Intussusception / Q000000981:diagnostic imaging* / Q000628:therapy; D007813:Laparotomy; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome; D014463:Ultrasonography