A four-month-old female Shepherd mix presented with a two day history of vomiting multiple times daily. Abdominal palpation demonstrated a tense abdomen and a possible firm tubular structure in the region of the cranial abdomen. An upper GI examination using barium was performed prior to referral. Transit of contrast material into the colon was identified by four hours post administration, reflecting normal transit time. A persistent filling defect was identified within the transverse colon.
Upon arrival of the patient at our facility, additional radiographs were performed. Radiographs demonstrated transit of the contrast material from the small intestine, and a persistent filling defect within the descending and transverse colon. There was a ‘coiled-spring’ appearance involving the filling defect which is consistent with the diagnosis of intussusception. The cecum did not appear to be involved. Surgical exploratory revealed a non-reducible intussusception involving the entire ileum and a portion of the jejunum.
An intussusception is defined as the invagination of one portion of the gastrointestinal tract into the lumen of an adjacent segment. The receiving segment is known as the intussuscipiens and the invaginated segment is termed the intussusceptum. The causes of intussusception include inflammatory lesions, motility disorders, idiopathic causes and intestinal parasitism. The majority of the lesions involve the small intestine or ileocolic junction. Radiographs in these patients often demonstrate signs of mechanical obstruction prompting surgical intervention, however definitive diagnosis of intussusception can be difficult based on radiographs alone. Ultrasound is the imaging modality of choice in these cases. A contrast examination using barium sulfate suspension can be performed if access to ultrasound is not available. The ‘coiled-spring’ appearance of the contrast material at the site of intussusception is a hallmark radiographic sign of this lesion, and is due to a small quantity of contrast medium outlining the serosal surface of the intussusceptum. Contrast medium introduced into the rectum is preferred over oral administration if an ileocolic intussussception is suspected, in order to hasten delivery of contrast material to the site.