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239
Hellenic Journal of Surgery 2010; 82: 2
Is There a Correlation Between Hypertrophic Pyloric Stenosis
and Congenital Abnormalities of the Urinary Tract in Children?
Retrospective Clinical Study
N. Partalis, E. Blevrakis, G. Sakellaris
Received 20/04/2010 Accepted 31/05/2010
Abstract
Aim- Background: Numerous clinical associations and
congenital abnormalities have been described in combination with hypertrophic pyloric stenosis (HPS) in
infants. The correlation between HPS and congenital abnormalities has not yet been clarified. The aim
of this study is to assess whether there is a common
appearance of these two conditions and whether an
extra testing of the urinary tract is needed.
Patients and methods: Fifty-six children who had undergone surgery for HPS between 2001 and 2005
were retrospectively evaluated. History was obtained
and ultrasound screening of the urinary tract was performed.
Results: The ultrasound screening revealed a double
renal pelvis system in one boy (1.7%). Twelve (21%)
children had an incidence of urinary tract infection
(UTI) and two boys (3%) had a positive history for
nocturnal enuresis. There is no correlation between
hypertrophic pyloric stenosis and congenital abnormalities of the urinary tract, since the difference between the incidence of congenital malformations of
the urinary tract in the general population and the
population with HPS is insignificant.
Conclusion: We do not recommend additional testing
of the urinary tract in children with HPS, but more
research is required to establish whether there are
functional disorders of the urinary tract in the population with HPS.
Keywords
Hypertrophic pyloric stenosis, Congenital abnormalities, Urinary
tract in children
Introduction
Hypertrophic pyloric stenosis (HPS) is a condition
of hypertrophy of the pylorus, with elongation and
Department of Paediatric Surgery, University Hospital of Heraklio, Greece
e-mail: gsakell@mycosmos.gr
thickening, eventually progressing to near-complete
obstruction of the gastric outlet. HPS is the most
common paediatric surgical disorder that requires
surgery for associated emesis in the first few months
of life. The incidence of HPS is reported to be approximately 2 to 3.5 in 1000 live births, although
rates and trends vary markedly from region to region [1-5].
Numerous clinical associations have been described with HPS. Hyperbilirubinaemia is one of
them occurring in 14% of cases in one series [6].
Furthermore, congenital malformations, including
midgut malrotation (up to 5% of infants with HPS),
congenital heart disease [7], diaphragmatic [8] and
hiatal [9] hernia, Meckel’s diverticulum and oesophageal atresia, have also been reported [10-12].
A trial to clarify whether there is any association
between HPS and congenital malformations of the
urinary tract has been conducted with inconclusive
results. The aim of this study is to amplify the attempt to resolve the possible connection between
these two congenital malformations and to be able
to express a solid opinion on whether there should
be further ultrasonographic tests for the children
with HPS.
Patients and Methods
During the years 2001 to 2005, 64 patients underwent pyloromyotomy for the diagnosis of hypertrophic pyloric stenosis. Fifty six of these patients were
reassessed retrospectively by a paediatric surgeon.
The remaining 8 patients did not meet their appointments. All patients were treated surgically by
the Fredet-Ramstedt procedure at the first month
of their life and there were no complications during
and after the procedure. Diagnosis of hypertrophic
pyloric stenosis was made, based on history and
clinical examination, which was corroborated by an
abdominal ultrasound. The diagnosis was confirmed
during surgery.
All patients had their history reassessed by the
same paediatric surgeon before undergoing ultrasound screening of the urinary tract by the same
radiologist.
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Hellenic Journal of Surgery 2010; 82: 2
Results
Of the 56 infants and children with hypertrophic
pyloric stenosis who were assessed by ultrasound
screening of the urinary tract, 45 were boys and 11
were girls with a male to female ratio of 4.1:1. The
age varied from 21 days to 8 years with a mean of 5
years. Out of the 56 children and infants, 12 (21%)
had a previous incidence of urinary tract infection
(UTI), 10 of whom were boys and 2 were girls. Two
boys (3%) had (under the age of four) a positive
history for nocturnal enuresis. No family history of
HPS was reported and there was no coexisting disease, either congenital or acquired.
On clinical examination, none of the children
were found to have a developmental or functional
problem with the urogenital system. Ultrasound
screening of the urinary tract revealed the existence
of a right double renal pelvis in a boy (1.7%), who
also had a UTI. It did not reveal any problems at the
shape or the matrix of the kidney, the ureters, the
urinary bladder or the urethra in any of the other
children.
Discussion
Hypertrophic pyloric stenosis is a condition that
causes severe vomiting in the first weeks of life.
There is narrowing of the pylorus due to the enlargement of the pyloric muscle, which spasms when the
stomach empties. It is uncertain whether there is a
real congenital narrowing or a functional hypertrophy of the muscle which develops in the first weeks
of life. However, it is probable that there is a genetic
predisposition for the development of HPS [13].
Numerous clinical associations with HPS in infants have been described. Hyperbilirubinaemia is
the most frequent clinical association occurring in
14 percent of cases in one series [6]. HPS has also
been correlated with midgut malrotation [14], joint
hypermobility [15,16], congenital heart disease [7],
congenital hypothyroidism [17],hernias [8,9] and
other congenital diseases. An association between
congenital anomalies of the urinary tract and HPS
has been suggested by a few case reports, amongst
which one case of hydronephrosis [18], one of nephrotic syndrome [19] and another of newborn twins
and their father with polycystic kidney disease [20]
were found to have HPS.
Apart from these reports, several studies have
examined series of infants with HPS to determine
a potential relation with congenital uropathies. In
1981, Atwell et al [21], studied two series and found
an abnormality of the urinary tract, either major or
minor, in 20.6% of the infants in the first series and
2.7% in the other. The percentage of these abnor-
Is There a Correlation Between Hypertrophic Pyloric Stenosis and
Congenital Abnormalities of the Urinary Tract in Children?
malities was 4%, as recorded by Fernbach et al. in
1993 [22], 1.4% by Bidair et al. in 1993 [23] and 1%
by Moshe Nussinovitch et al. in 1998 [24]. Similarly,
the percentage of the urinary abnormalities was not
high in the series of Applegate Ms in 1995 and of S.
Cascio (4%) in 2005 [25]. In our series, the percentage of major urinary malformations was 1.7% (one
boy) and of minor malformations 0%, which could
be explained by the small population of our study.
Routine ultrasound screening of the urinary tract
in the neonatal population shows an incidence of
1–2% for major anomalies and up to 5% for minor
anomalies [26, t27]. Since there is no significant difference in incidence of either major or minor abnormalities of the urinary tract in the general population, with the exception of the small series of Atwell
[21], it may be safe to assume that these two entities
do not have a connection between their congenital
causes.
Renal ultrasonography is the test of choice to
exclude urinary tract abnormalities, thereby avoiding the potential allergic and toxic complications of
radiocontrast media and avoiding an invasive approach. The specificity and sensitivity is not as good
as in other radiographic tests but since no abnormalities of the urinary tract were found, no further
testing was done.
The incidence of urinary tract infection in our
study was 21%. Moshe Nussinovitch et al [24] found
a prevalence of 2.8% of UTI in infants with HPS,
which was 20 times higher than the general population [23]. The overall prevalence of UTI is approximately 7% in febrile infants and young children [2830]. The high incidence in our series suggests that
there is an association between HPS and UTI, warranting further thorough research. Only one of the
children with UTI had a positive ultrasonographic
examination, which could lead to a functioning disorder of the urinary system, such as vesicoureteral
reflux. However, more examinations must be done
in order to exclude false negative results from the
ultrasound scan, such as urodynamics and magnetic
resinance imaging (MRI).
Conclusion
Since there is no significant difference between the
incidence of congenital malformations of the urinary tract in the general or the healthy population
and the population with HPS, it would appear that
there is no correlation between hypertrophic pyloric
stenosis and congenital abnormalities of the urinary
tract. Our Department does not recommend additional testing of the urinary tract in children with
HPS to the already existing screening test. Further
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