Helicobacter pylori - Portal Neonatal

22
Congenital problems of the gastrointestinal tract
system with an incidence of approximately 1 in
5000 live births. 24–26 Whilst most cases are
sporadic a positive familial occurrence exists in
3.6–7.8% of cases 27 and the presence of co-existing
abnormalities including trisomy 21 suggests a
genetic involvement (see also Chapter 17).
This condition is characterized by the absence of
enteric neurons and hypertrophy of nerve trunks
in the distal bowel always involving the rectum
and for a variable distance proximally. There is an
absence of peristaltic activity in this aganglionic
segment resulting in symptoms of intractable
constipation. The bowel proximal to the aganglionic
segment contains ganglionated cells, and
peristaltic activity is normal. However, in the socalled
transitional zone, immediately proximal to
the aganglionic segment, neuronal cells may exist
but they are commonly of abnormal architecture
and the intestinal peristalsis is abnormal. This
zone is of fundamental importance when considering
surgical treatment of this disorder.
Clinical features
In the neonatal period the disease should be
considered in any infant who fails to pass
meconium in the first 48h of life. The usual
presentation in the neonatal period is with constipation,
abdominal distension and eventually
vomiting during the first few days of life. More
severe symptoms may be present in the neonatal
period including those of gastrointestinal obstruction,
enterocolitis (see below) and rarely perforation.
Later in infancy symptoms of intractable
constipation may signify the presence of
Hirschsprung’s disease.
Diagnosis
One of the most important factors in the management
of Hirschsprung’s disease is early diagnosis
and appropriate treatment to avoid complications
of the disease. Following clinical suspicion a
number of investigations may be of use in making
a diagnosis which must always be confirmed by
histological examination of intestinal tissue. Plain
abdominal X-ray will often show dilated proximal
intestinal loops (Figure 2.6) prompting a lower GI
contrast study to be performed to exclude intestinal
atresia/stenosis or meconium ileus. This may
show a prompt transition from narrow distal
aganglionic bowel to dilated proximal bowel. A
contrast enema is not necessary for diagnosis in
many cases of Hirschsprung’s disease. In addition,
this investigation may be misleading in its indication
of the length of intestinal aganglionosis.
The gold standard for diagnosis is the suction
rectal biopsy. Characteristic histological findings
are absence of ganglion cells and increase in
acetylcholinesterase (AChE) staining in the
parasympathetic nerve fibers. In cases where
suction rectal biopsy fails to provide adequate
information, a full-thickness rectal biopsy should
be considered.
Treatment
Treatment in the first instance is aimed at decompression
of the distal GI tract by regular rectal
washouts. Subsequently a number of surgical
options exist, all of which aim to remove the aganglionic
segment and restore intestinal continuity by
means of an anastomosis of ganglionated bowel to
the rectal stump (so-called ‘pull-through’). This may
be performed either as a primary procedure or as a
delayed procedure after initial colostomy formation
Figure 2.6 Plain abdominal X-ray of a child with
rectosigmoid Hirschsprung’s disease showing extensively
dilated loops of bowel.