Histoanatomic Features Distinguishing Aganglionosis in Hirschsprung's Disease: Toward a Diagnostic Algorithm

Area of Science:

• Pediatric Surgery
• Gastroenterology
• Histopathology

Background:

• Intraoperative frozen biopsies are standard for Hirschsprung's disease (HD) diagnosis but have limitations.
• A faster, real-time alternative is needed, requiring established differences between aganglionic and ganglionic bowel.
• Histoanatomical and morphometric analysis can reveal these differences.

Purpose of the Study:

• To compare bowel wall layer dimensions between aganglionic and ganglionic segments in pediatric HD specimens.
• To develop a diagnostic algorithm for distinguishing aganglionosis from ganglionosis.
• To assess correlations between full bowel wall thickness and patient age/weight.

Main Methods:

• Manual delineation of mucosa, submucosa, and muscularis propria layers on histopathological images.
• Automated calculation of mean layer thicknesses using custom image analysis software.
• Paired parametric tests to compare measurements between aganglionic and ganglionic segments.

Main Results:

• Ganglionic bowel exhibited significantly thicker muscularis interna (0.666 mm vs. 0.461 mm) and a higher muscularis interna/externa ratio compared to aganglionic bowel.
• A diagnostic algorithm based on these features achieved 100% accuracy in differentiating the segments.
• No significant differences in full bowel wall thickness were found, nor correlations with patient weight or age.

Conclusions:

• Histoanatomic layer thickness variations are key to distinguishing aganglionic from ganglionic bowel in HD.
• A reliable diagnostic algorithm can be developed based on these morphometric differences.
• Full bowel wall thickness is not a reliable indicator and is independent of patient age and weight.