What is the diagnostic accuracy of contrast enema for Hirschsprung disease during COVID-19 service disruption in Vietnam? A retrospective study.

OBJECTIVES

To assess the diagnostic accuracy of contrast enema for Hirschsprung disease in children when preoperative rectal suction biopsy was unavailable and to examine age-related diagnostic performance and the utility of individual radiographic signs.

DESIGN

Retrospective diagnostic accuracy study.

SETTING

A high-volume tertiary paediatric surgical centre in Hanoi, Vietnam, during a period of COVID-19 related service disruption from May 2020 to October 2021.

PARTICIPANTS

354 consecutive children aged 0 to under 16 years who underwent contrast enema for suspected Hirschsprung disease. Final diagnosis was established by intraoperative frozen section and postoperative histopathology for operated patients and by clinical follow-up for non-operated patients.

INTERVENTIONS: Not applicable.

PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was diagnostic accuracy of contrast enema versus the reference standard, expressed as sensitivity, specificity, positive predictive value and negative predictive value with 95% CIs. Secondary outcomes were age-stratified accuracy and the performance of individual radiographic signs.

RESULTS

Among 354 children, contrast enema yielded 131 true positives, 19 false positives, 20 false negatives and 184 true negatives. Overall sensitivity was 86.75% (95% CI 80.43 to 91.26), specificity 90.64% (95% CI 85.85 to 93.93), positive predictive value 87.33% (95% CI 81.06 to 91.74) and negative predictive value 90.20% (95% CI 85.34 to 93.56). Sensitivity was higher in children aged 1 month or less than in those older than 1 month, 96.00% vs 75.71%, whereas specificity was lower, 80.00% vs 97.67%. Of the individual radiographic signs, the inverted rectosigmoid index was the most sensitive, while the irregular mucosal pattern was the most specific.

CONCLUSIONS

Contrast enema showed moderate to high diagnostic accuracy for Hirschsprung disease in this biopsy-constrained setting and may be useful as a triage tool within a limited diagnostic pathway. However, its false negative rate indicates that it should not be used as a standalone rule-out test when histological confirmation is available.