Background and objective: The cardinal diagnostic sign of congenital aganglionic megacolon, or Hirschsprung's disease (HD), is an aganglionic segment of the distal colon or rectum. To determine the surgical planning of a radiological transition zone (TZ) in HD, this study investigated the association between a radiological TZ and the bowel resection length.
Methods: A prospective observational study was conducted in children (n = 192) with suspected HD determined by radiological TZ on contrast barium enema, and who underwent pull-through operations. The bowel resection length was ≥10 cm above the proximal radiological TZ levels and confirmed by intraoperative frozen sections. In the contrast enema, the presence and level of a radiological TZ were recorded. Correlation of the TZ features with ganglion cells assessed by immunostaining of neuronal nuclei (NeuN) and the odds ratio were calculated.
Results: The sensitivity and specificity for diagnosing HD by the presence of a radiological TZ were 86.9 and 92.1%, respectively; Youden's index was 79.0%. The positive and negative predictive values were 91.7 and 87.6%. The kappa value indicating an association between TZ and HD was 0.776 (P < 0.05). The correlation rate between a radiological TZ and the pathological results was 88.5% in the rectosigmoid colon and 44.4% in the descending colon, and was higher in children older than 3 months (85.3%) than in infants (69.0%).
Conclusion: A preoperatively determined radiological TZ has potential value to identify the length of resected bowel in patients with HD, and it also has a high predictive value for diagnosis of HD.
Keywords: Barium enema; Hirschsprung’s disease; Radiological transition zone.