Let's take a look at Duodenal atresia. What does
the term "atresia" mean? Lack of development.
"Atresia" means lack of development. Here the
duodenum is not developed properly. Why?
Oh, it could be genetic, maybe associated with
Down Syndrome. So duodenal atresia, Down syndrome.
On abdominal X-ray, you'd find double bubble sign. D−D−D.
Once again, duodenal atresia, Down syndrome, Double bubble.
Know those. Trisomy 21, Down syndrome. Signs and symptoms.
The vomit that you'd find here with duodenal atresia
is the fact that now I want you to think normal physio−anatomy.
And we have the bile duct. The bile duct is then
going to connect to the, with the pancreatic duct
will connect to the second part of the duodenum.
It connects so that you emulsify the lipids so on
and so forth but you're in the second part of the duodenum
and then you end in a pouch. You're in the second part
of the duodenum. The bile duct just connected, okay.
So you don't have a problem with that but the rest
of it doesn't canalize properly. So the failure of
recanalization of the two parts of duodenum in which
the bile duct is still connecting. When you vomit,
what's coming out is going to be yellow and green.
Are we clear? So we call this a bilious type of vomit.
Whereas in physiology and embryology, you'll learn about
pyloric stenosis. In that type of vomit, think about
the pylorus, it's not even close to the bile duct,
right? So therefore, that type of vomit that you find
with that first born male with pyloric stenosis would
be projectile and they would be non−bilious.
This would be bilious. Often on first day of life.
Usually abdominal distention because of lack of
recanalization of your duodenum. And simple, simple
concept. For amniotic fluid circulation in utero
in which you can get any question in utero when dealing
with hydramnios, correct. Listen, womb of a mother,
amniotic fluids surrounding the fetus in the placenta, right?
This amniotic fluid allows for space for the fetus
to develop. Circulation that you want to keep in mind
so that you get all clinical questions right
for amniotic fluid. The baby, the fetus, in utero
swallows the amniotic fluid. Then the amniotic fluid
would have passed through the body and the fetus is
going to urinate the amniotic fluid "into the placenta".
Work with me here. If the duodenum doesn't form properly,
failure to recanalize, the fetus in utero is going to
then vomit "the amniotic fluid back into the placenta".
Upon ultrasound, what are you gonna find?
Polyhydramnios. What if the trachea and the esophagus
are connected? It's called the tracheoesophageal fistula.
What if the esophagus doesn't form properly, called
esophageal atresia. In embroyology, remember,
here in utero, the fetus is going to "vomit the amniotic
fluid into placenta". In esophageal atresia,
what are you going to find on ultrasound on a pregnant
lady? Polyhydramnios. What about the kidney?
If the kidneys don't form bilaterally, called
bilateral renal agenesis. May be secondary to
Autosomal Recessive Polycystic Kidney Disease then
you've heard of something called Potter sequence.
You understand the simple concept that I've
given you for amniotic fluid in utero. The fetus
"swallows the amniotic fluid and recycles it constantly".
Polyhydramnios, abdominal distention, bilious vomiting,
welcome to duodenal atresia. D−D−D. Duodenal
atresia, Down Syndrome, double bubble sign.
On your abdominal x−ray, take a look at the two major
areas on your abdominal x−ray. You find black
lucent bubble number one, black lucent
bubble number two. Double bubble sign.
Treatment, surgery. It's Atresia.