Didactic Year Exams

Intussusception is the most common abdominal emergency seen in young children. It occurs when a part of the intestine invaginates or telescopes into itself, causing a bowel obstruction. Intussusception generally occurs between 6 and 36 months of age, with boys affected more frequently than girls. Most cases have an idiopathic etiology. Patients generally present with complaints of vomiting, intermittent or colicky abdominal pain, lethargy, and rectal bleeding. Vomiting is initially nonbilious, but when the obstruction occurs, it becomes bilious. Parents may report the child draws their legs up toward the abdomen or kicks their legs in the air due to the pain. Lethargy is commonly seen and may be intermittent in nature. Stools can be a mixture of mucus, blood, and sloughed mucosa, with an appearance described as currant jelly. Diarrhea may also occur in the early stages of the condition. Patients may often not have the classic signs of intussusception, which can delay the diagnosis and cause the condition to become more life-threatening. Ultrasound has a high sensitivity and specificity in the diagnosis of intussusception and is the method of choice at many hospitals. The classic finding on ultrasound is the target sign, which occurs when layers of intestine are within the intestine. Treatment options include nonoperative reduction or surgical intervention. Younger patients with an idiopathic cause to the intussusception are generally responsive to nonoperative intervention. Nonoperative reduction is with a therapeutic enema under fluoroscopic or ultrasound guidance. The two types of therapeutic enemas used are hydrostatic with either water-soluble or barium contrast or pneumatic air insufflation. Surgery is indicated when the patient is unstable, nonoperative reduction is unsuccessful, or there is peritonitis or intestinal perforation.

Intussusception can be seen on computed tomography (CT) scan (A), and it can be a useful tool in the diagnosis as well as helping to identify the cause. The negative aspects of CT scan include excessive radiation exposure, risk related to intravenous contrast, and need for sedation. CT scan is reserved for individuals with a high suspicion for intussusception who have nonspecific findings with other imaging modalities or when there is a need to determine the etiology. Magnetic resonance imaging (B) is not used in the diagnosis or management of intussusception. The initial evaluation of a patient suspected of having intussusception should include both plain radiography (C) and ultrasound. Radiography can be used to exclude intestinal perforation and can also support the diagnosis seen on ultrasound.