The contrast enema for Hirschsprung disease: predictors of a false-positive result

Area of Science:

• Pediatric Surgery
• Diagnostic Imaging
• Gastroenterology

Background:

• Hirschsprung disease (HD) diagnosis often involves contrast enema (CE) and rectal biopsy.
• False-positive (FP) results on CE can lead to unnecessary invasive procedures.
• Identifying predictors of FP results is crucial for optimizing diagnostic pathways.

Purpose of the Study:

• To investigate factors associated with false-positive (FP) results on contrast enema (CE) in infants suspected of having Hirschsprung disease (HD).
• To identify a subgroup of infants where rectal biopsy might be avoidable following abnormal CE findings.

Main Methods:

• Retrospective analysis of infants (<6 months) undergoing rectal biopsy after CE abnormalities between 1999-2004.
• Abnormal CE findings included transition zone (TZ), abnormal rectosigmoid ratio, microcolon, retained contrast, or mucosal irregularity.
• Multivariable logistic regression was used to identify independent predictors of FP results.

Main Results:

• A false-positive rate of 48.5% was observed in 129 patients who underwent rectal biopsy.
• Infants younger than 30 days (OR, 3.4), female sex (OR, 3.4), and absence of a TZ (OR, 6.3) were associated with increased FP risk.
• A history of bilious emesis decreased the probability of a false-positive result (OR, 0.2).

Conclusions:

• Key predictors of false-positive contrast enema results in suspected Hirschsprung disease include transition zone presence, sex, age, and bilious emesis.
• Infants younger than 30 days without bilious emesis or a TZ, and female infants with these characteristics, may represent a population where rectal biopsy can be safely omitted.
• These findings can help refine the diagnostic approach for Hirschsprung disease, potentially reducing unnecessary biopsies.