Intestinal dilated loops

Sonography has a role in high intestinal obstruction, especially in patients with lack of air in the gastrointestinal tract whenever marked distension of the flanks and elevation of the diaphragms is observed on the plain radiograph. In such cases, sonography is useful to differentiate the presence of multiple dilated loops filled with fluid from ascites (Fig. 1.18). It is also useful in demonstrating associ-... 

The radiological diagnosis of obstruction is usually visible on the conventional (plain) radiograph. In uncomplicated cases these radiographs of the abdomen are sufficient. The pre-atretic intestinal loops are dilated because of accumulation of large amounts of fluid and fluid levels are usually present on horizontal beam films. In case of jejunal atresia only a few loops of distended jejunum are present in the left upper abdomen, while in ileal atresia many dilated loops are identified. In complicated cases, especially with an abnormally distended and painful abdomen, a colon enema or US can be useful- particularly from the differential diagnostic point of view to exclude meconium ileus or meconium peritonitis. In case of atresia, a microcolon without the presence of meconium is usually found (Devos and Meradji 2003). 

Fig. 1.14a,b. Jejunal atresia, a Supine radiograph shows a few dilated, air-filled intestinal loops, about four bubbles , which indicates a high obstruction, b Surgical image demonstrates the location of the atresia (arrow), the dilated proximal jejunum, and the small caliber of the bowel distal to the atresia... 

On a supine film changes such as dilatation with or without obstruction, calcification and displacement of normal structures can all be identified and localized. Multiple (distended) loops are indicative of distal pathology (Fig. 5.2), whereas a few (distended) loops suggest proximal intestinal pathology (Fig. 5.3). 

Diagnosis is made by plain film and US. Plain film shows a swollen abdomen with a few or no air-containing bowel loops (Fig. 5.8). The bowel loops may be variably dilated. Often calcifications are visible. US shows not only the calcifications but also the extraluminal meconium and cystic fluid accumulations. The wall of the intestine is thickened (Fig. 5.9) (Parker 2003 Devos and Meradji 2003). 

Fig. 5.13. a A premature infant with intestinal dysfunction, so-called meconium ileus-like syndrome. The supine abdominal film shows dilated intestinal loops because of fecal impaction in ileum, b Cross-table radiograph. Meconium-like ileus with dilated intestinal loops without fluid levels. The whole colonic tract and rectum are airless, c Ultrasound of the right lower quadrant of abdomen demonstrates the impacted and inspissated stool in the ileum... 

Fig. 5.18a,b. Mechanical intestinal obstruction after complicated and perforated appendectomy in a girl. Note the dilated intestinal loops (a) and multiple fluid levels on lateral film (b)... 

Fig. 5.27. A boy with cystic fibrosis complicated with distal intestinal obstruction syndrome. Note the dilated intestinal loops and huge fecal impaction in the terminal ileum and caecum...

The pattern of complications is common for all types of hernia. The complications are irreducibility, obstruction and strangulation. Irreducible (incarcerated) hernia may be due to a narrow neck or adhesion of contents to the sac wall. In obstruction, the intestine in the hernia gets obstructed due to a narrow neck, adhesion or volvulus, but it is viable. Strangulation results when there is compromise to venous drainage and later arterial supply of the contents. In obstructed hernia there is colicky pain, abdominal distension and vomiting. Incarcerated hernia is present at rest it is irreducible and usually contains some fluid in the sac that can be seen on sonography (Fig. 5.2b Rettenbacher et al. 2001). In obstructed hernia the patient has symptoms of intestinal obstruction. There are dilated bowel loops... 

Frequent US findings of primary intestinal lymphangiectasia are a markedly dilated small intestinal loop with increased (mixed but mainly echogenic) fluid content (Fig. 10.1), and small bowel tract with regular and diffuse bowel wall thickening and mesenteric oedema (Fig. 10.2). 

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