In this talk, we're going to cover
Hypertrophic Pyloric Stenosis.
Try saying that
three times quickly.
Stenosis is essentially
a functional obstruction
of the gastric outlet.
We're not emptying
the stomach very well,
and it's caused by a combination
of smooth muscle hypertrophy,
meaning the individual cells of
the smooth muscle are bigger,
but there's also more of them.
This is occurring at the
pylorus for a variety of reasons
that we'll get to in a moment.
This is primarily a disease
of babies of neonates,
and we need to recognize
it in that period of time,
and much less commonly an issue
associated with older individuals.
We do, however,
need to distinguish this
from other causes of
gastric outlet obstruction
that could be peptic
cancer at that location,
or a bezoar, a hairball,
that literally that's
what bezoar is.
So the epidemiology of
the pyloric hypertrophy.
It's most common cause of
intestinal obstruction in infants.
it occurs to some extent,
in 1-3 per 1000 live births
in the United States.
And that frequency pretty
much holds around the world.
For reasons related to genetics,
it's more common in Caucasians,
whites in males, firstborns,
and those who have blood groups B or O.
And clearly, if you have a family
history of pyloric stenosis,
there's a genetic basis for
thinking that you may have it again,
in another member
of your family.
Clearly, there's a genetic basis,
there's congenital disease,
and it's very closely associated,
for example, with trisomy 18.
Although other genetic changes may be
associated with the pyloric stenosis.
It can be associated with
inflammatory diseases as well,
such as eosinophilic
It may be a small,
but nevertheless very real side
effect of drugs that are taken
during gestation by mom,
such as erythromycin.
Or it can be associated with defects
deficits in muscle relaxation.
So if the muscle doesn't
make enough nitric oxide,
then you won't relax as well
and you will get hypertrophy
and hyperplasia of
the smooth muscle.
The clinical presentation
is as you expect
for a gastric
So in the neonatal
period of time,
it usually starts within
three weeks of delivery.
Initially, what will happen is that
there'll be regurgitation after feeding.
So food will not be able to pass
and then we'll be vomited back up.
because the obstruction
to where the bile ducts
dump into the duodenum.
So it's not going to
be bilious vomiting,
but it can be over time with very
severe retrograde movement of food,
it can be projectile.
The infant is clearly hungry.
The infant is not getting food delivered
into the other part of the GI tract.
And so they will be
they'll exhibit signs of hunger.
There won't be very
good weight gain.
You may even feel with an enlarged
hypertrophied muscle mass,
an actual mass, a periumbilical mass where
the the muscle at the pylorus is thickened.
You may also be able to perceive
particularly as the infant loses weight,
a gastric peristaltic wave across
the abdomen after feedings.
So the stomach is trying its very best
to push food through that stenosis.
And it's not able to but you'll see a
very prominent gastric contraction wave.
Clearly, as the infant is
not feeding appropriately,
or is not able to eat and move
food into the rest of the GI tract,
there'll be signs
So it's a constellation
of the clinical findings.
On the laboratories that again,
it's what you might expect if
there is recurrent emesis vomiting,
there's going to be a
hypochloremic metabolic alkalosis.
That's due to the
Because of the alkalosis,
we're actually going
to be chasing potassium
into cells in
exchange for protons.
So we'll have a
There may be elevated blood
urea nitrogen and creatinine
so renal parameters are going to
be elevated due to dehydration.
this is an ultrasonographic diagnosis,
there's going to be a thickened
prominent pylorus that you can identify.
And usually with more
proximal gastric dilation.
How do we manage this?
So until we can do the operation
to open that tight stenosis,
we're going to make sure that the infant,
it gets adequate fluid replacement.
We're going to correct any
that hypokalemia that acidosis.
We're going to restore
the acid base balance
and try to get the renal parameters
more normalized with fluids.
a couple of different approaches.
So you can do a myotomy, so you can
actually go in even endoscopically
and cut the smooth muscle and hopefully
that will cause sufficient relaxation
that you'll no longer have that
functional stenosis and obstruction.
Or you can do an laparoscopic
pyeloplasty where you actually go in
and dilate the very
Okay, not a super common entity,
but one that you need to recognize
in the pediatric population
as an important pathology associated
with gastric outlet obstruction.
And we'll conclude here.