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Volume 4 No. 2, April 2009 |
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Feasibility of Low Segment Hirschsprung's Disease to Minimal Surgery: Screening By Radiological Criteria A. Ghobashi (1) & S. M. K. Shehata(2)
Departments of Radiology(1) & Surgery(2),
Faculty of Medicine, Tanta University, Egypt
Background/Aim: Hirschsprung's disease is the most common cause
of constipation in childhood. Some cases have benefited from the
minor surgical intervention in the form of anorectal myectomy
especially those of low segment type. Still the radiological signs
present an important diagnostic tool in this disease; despite its
low accuracy. Detection of transitional zone (TZ) at infra levator
or supra levator positions in Hirschsprung's disease (HD) is not
stressed as preoperative assessment. The aim of this work is to
define radiological parameters in screening cases of low segment HD
amenable to minor surgical intervention we propose this study.
Patients & Methods: we studied the contrast radiological data of 164
infants and children suffering from chronic constipation to suspect
low segment HD. This revision, with review of the literature
resulted in five radiological signs suspect the location of TZ in
low segment HD to be infra levator. Retrospectively we applied these
signs to the patients' preoperative barium radiograms of 25 patients
who were subjected to the myectomy and histologically proved HD. The
clinical and follow up sheets of cases were revised to evaluate the
accuracy of these signs in screening this group of HD amenable to
myectomy. Results were expressed using the sensitivity / specificity
test. Results: Twenty-one patients were responding well to myectomy,
while the rest were non-responders. The five positive radiological
parameters defined were: a) Transitional zone (TZ) at or below the
pubococcygeal line in lateral view, b) TZ at or below the
interacetabular line in postero-anterior view, c) TZ detected in
early delayed films at 30 minutes post enema in one of the previous
low positions, d) TZ detected in late delayed films at 24 hours in
one of the previous low positions, and e) No TZ, bu^Fecfbcolonic
dilatation was seen down to the anus. Radiological signs were
recognized among responders with the following frequencies as 14/21
for sign a, 13/21 for sign b, 11/21 for sign c, 10/21 for sign d,
and 7/21 for sign e. Sign a gives the highest positive predictive
value relating the good response to myectomy. Results were evaluated
using the sensitivity / specificity test. A prognostic score has
been postulated ranged from 0 to 8. Score of 4 or more gives a good
prognostic rating more than 70% to myectomy. Conclusions: Infra
levator HD gives good response to anorectal myectomy. Our simple
score proves this. These five radiological parameters form the base
of screening HD amenable to minor intervention when correlated to
the clinical and investigative data. A screening system is feasible
and valuable to convey a level of diagnostic probability. Although
our study is retrospective, we invite the clinicians to apply these
radiological screening parameters to Ba enema of HD before time of
biopsy. This screening leads to good results from minimal
therapeutic surgical procedure and subsequently less hospital stay
and less costs.
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