Background and purpose: Rectal biopsy is the main modality for the diagnosis of Hirschsprung’s disease (HD). In Africa, transanal full-thickness rectal biopsy is commonly performed. We aimed to audit our practice of rectal biopsy in the evaluation of HD.
Materials and methods: A retrospective review was carried out of the records of children (≤15 years) who were evaluated for HD between 2007 and 2011. Clinical presentation, details of the operation, and histologic result were analyzed using SPSS version 15.0.
Results: Fifty-seven children were evaluated for suspected HD during the period. Thirty-six children underwent a rectal biopsy. There were 29 (80.6%) males and nine (19.4%) females, of which two were preterm. Neonates and infants accounted for 72.2% (n=26). The median age at biopsy was 90 days (range, 5 days to 9 years). Delayed passage of meconium was present in 64.7%, constipation in 85.7%, abdominal distension in 88.6%, and bilious vomiting in 55.9%. Thirty biopsies (83.3%) yielded a histologic diagnosis. Twenty-six (72.2%) confirmed HD, whereas four (11.1%) yielded normal rectal histology. In six (16.7%), the sample taken was deemed inadequate for opinion. None of the symptoms assessed was associated significantly with a diagnosis of HD, stalling further analysis. Where a single biopsy was taken, 20% (n=5) were inadequate for analysis; where more than one sample was taken, a histologic diagnosis was possible in 100% (n=11). Consultant surgeons and trainees returned inadequate samples in 15.8% (n=3) and 12.5% (n=2), respectively. An inadequate sample was obtained in four infants (15.4%) and one child older than 1 year of age (10%). Distance of biopsy from the dentate was not indicated in 63.9% (n=23).
Conclusion: No clinical parameter can accurately predict a diagnosis of HD. More than one sample at a sitting may improve the diagnostic yield. Larger prospective studies are needed to confirm these findings.