Thanks for joining me
on this discussion of intussusception
in the section of pediatric surgery.
why does it happen?
We don't exactly know,
but there are some theories.
Most intussusception are idiopathic
and they occur at the
terminal ilium to the cecum.
This is also known as ileocolic.
This is the type that often
happen in infants and toddlers.
Here, you see another anatomy picture
of the terminal ilium
actually invaginating itself into the colon.
There may be some truth behind
probably lymph node hypertrophy.
Because commonly this follows
a recent respiratory infection.
We think with a systemic infection
that the lymph nodes may actually hypertrophy
and creating itself a lead point
or idiopathic ileocolic intussusception.
Here is a picture of, intraoperatively,
what we find in intussusception.
As you can see from this image,
a segment of small intestines
is invaginating into another.
This is the reason why
it may cause obstruction
and/or abdominal pain.
How does the intestines become
ischemic during this process?
I’ll show you using this image
and the next few slides.
recognize that the lymphatic obstruction
is actually what occurs first.
Commonly, when people think
about intestinal ischemia,
they think that the arterial
supply is actually compromised first.
But there's a protective mechanism
whereby the arterial blood pressure
is usually the last to go.
After lymphatic obstruction,
the venous side drainage is obstructed.
And now you can imagine,
with lymphatics and venous obstruction,
or arterial supply
is subsequently obstructed.
This is like a multiple car accident.
There's going to be a pylon.
And towards the end of that
scenario is arterial obstruction,
and subsequently ischemia.
This is also a reason
you often see ischemic bowel very dilated.
That's because of the venous
and lymphatic congestion.
Let's take a look at the schematic
of what happens during an intussusception.
On the left side of the screen,
as we already previously discussed,
are potential etiologies of intussusception.
the vast majority of these
are still idiopathic in kids.
Enlarged Peyer’s patches,
particularly as associated with
a viral upper respiratory infection,
increases the chance of a lead point.
some children may have
an inflamed appendix,
demonstrated in the left side of the screen.
As you can see on the
right top half of the screen,
the intestines proximally actually invaginates
into the proximal small bowel.
And as a result,
in the right lower quadrant of the screen,
you notice that the intussusceptum,
or the portion of the bowel
that enters the proximal bowel,
now appears edematous.
Upstream of this edematous bowel
can present with small bowel obstruction.
As you can imagine,
when venous and lymphatic drainage is obstructed,
it may need to ultimately arterial obstruction
and subsequent bowel ischemia.
lead points may not
always be present.