Pediatric Crohn Disease Surgery Workup

Updated: Jul 26, 2019
  • Author: Patricia A Valusek, MD; Chief Editor: Harsh Grewal, MD, FACS, FAAP  more...
  • Print
Workup

Laboratory Studies

Stool specimens are sent for investigation of possible infectious causes for the patient’s symptoms.

Laboratory examinations may demonstrate manifestations of the disease, such as anemia of chronic disease, evidence of malnutrition, or an increased erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) level.

A complete blood count (CBC) may show anemia caused by iron, vitamin B12, or folic acid deficiency.

Albumin and prealbumin levels reflect levels of nutrition. Deficiencies of trace elements such as zinc, selenium, and copper are common.

Electrolyte analysis, with calcium and magnesium studies, can help in assessing level of hydration, renal function, and malabsorption.

Fat malabsorption may lead to decreased levels of the fat-soluble vitamins. Therefore, prothrombin times, vitamin A levels, and vitamin D levels may be assessed.

Liver function test results may be elevated, either transiently because of inflammation or chronically because of sclerosing cholangitis.

Amylase and lipase levels may be elevated because of drug-induced pancreatitis. Azathioprine, 6-mercaptopurine, and 5-aminosalacylic acid can all cause pancreatitis.

Next:

Imaging Studies

Computed tomography (CT) should be the first radiologic procedure performed in patients with acute inflammatory symptoms (see the image below). CT may show bowel-wall thickening, mesenteric edema, abscesses, or fistulas.

CT scan in a patient with terminal ileal Crohn dis CT scan in a patient with terminal ileal Crohn disease shows an enteroenteral fistula (arrow) between loops of diseased small intestine.

Small-bowel contrast and enteroclysis studies may be valuable in demonstrating the distribution of small-bowel disease (see the image below). [18] Mucosal fissures, bowel fistulas, strictures, and obstructions can be visualized. The terminal ileum may be narrowed and thickened, with a characteristic pipe appearance.

A teenaged patient with Crohn disease underwent a A teenaged patient with Crohn disease underwent a contrast-enhanced upper-GI study with small-bowel follow-through. Several loops of small bowel are in the pelvis. Note 1 loop of distal bowel with a thickened wall (solid arrow), which is contrasted with a less involved loop of bowel in which the intestinal wall is not thickened at all (dotted arrow).

In several studies, magnetic resonance imaging (MRI) has been shown to yield a higher sensitivity and specificity than ileocolonoscopy (criterion standard) for both the diagnosis of Crohn disease (CD) and the determination of its severity. [19, 20, 21]

Guidelines on the use of CT enterography (CTE) and magnetic resonance enterography (MRE) have been published by the Society of Abdominal Radiology (SAR), the Society of Pediatric Radiology (SPR), and the American Gastroenterological Association (AGA). [22, 23] (See Guidelines.)

Previous
Next:

Diagnostic Procedures

Endoscopic visualization and biopsy are essential in the diagnosis of CD.

Colonoscopy with intubation of the terminal ileum is used to evaluate the extent of disease, to demonstrate strictures and fistulas, and to obtain biopsy samples to help differentiate the process from other inflammatory conditions. Given the increased risk of colorectal cancer in patients with inflammatory bowel disease (IBD), colonoscopy may have a role in cancer surveillance, though this practice remains controversial.

Upper gastrointestinal (GI) endoscopy may be used to diagnose gastroduodenal disease. It is recommended for all children regardless of the presence or absence of upper GI symptoms.

Despite extensive workup, 10% of patients with isolated Crohn colitis have an indeterminate colitis, with features of both CD and ulcerative colitis (UC). If these patients undergo long-term follow-up, small-bowel disease characteristic of CD ultimately develops.

Previous
Next:

Histologic Findings

Microscopically, CD is characterized by transmural inflammation of all layers of the bowel wall. In the mucosa, cryptitis, crypt abscesses, basal plasmacytosis, and crypt ulcers are commonly observed. Noncaseating granulomas in the bowel wall are characteristic but not pathognomonic of CD. Proliferative stromal and nodular inflammatory changes occur in the bowel wall, leading to a thick firm appearance and, ultimately, strictures.

Previous