Persistent Transition Zone In Hirschsprung Disease Despite Long-term Diversion: A Case-based Reappraisal Of Conventional Concepts
The transition zone (TZ)
in Hirschsprung disease (HD) represents the segment of the bowel that shows a
gradual decline in the number of ganglion cells from the proximal ganglionic
segment towards the distal aganglionic segment. Identification of the
transition zone radiologically during contrast enema plays a critical role in the
diagnosis and surgical planning. The classical understanding suggests that
diversion stomas or rectal washouts may obscure or eliminate the radiological
TZ. We present a case of a 5-year-old child with a long-standing diverting
colostomy in whom a well-defined TZ persisted despite prolonged diversion. This
case challenges traditional assumptions regarding the dynamic nature of the TZ.
A comprehensive review of embryology, pathophysiology, and literature suggests
that the TZ is established early during enteric nervous system development and
remains anatomically fixed, although its radiological expression may vary.
Understanding this concept has implications for diagnostic imaging, interpretation
of contrast studies, and operative decision-making.
Kitap Adı:
Olgular Eşliğinde Çocuk Cerrahisi
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