00:00
In this talk, we're going to cover
the topic of intestinal malrotation,
which occurs remarkably
quite frequently,
but in most cases,
is completely asymptomatic.
00:15
So intestinal malrotation is a failure of
the GI tract undergo its normal rotation.
00:20
You'll see in a moment,
we'll give you a video.
00:23
The bowel goes through some
pretty impressive contortions
as it develops in utero.
00:30
If it doesn't completely go
through its normal folding
and rotation around the mesenteric
vessels during embryogenesis,
then you can potentially
have some pathology.
00:42
The epidemiology, as they said,
this is remarkably common,
about 1 in 500 births.
00:48
It doesn't mean that all of these
babies are going to be symptomatic.
00:51
And indeed, many people are walking
around some of you watching this video,
who have this particular
anomaly, and you're just fine.
00:59
You'll see that it will vary depending
on the severity of the malrotation.
01:04
So about 30% of babies who have this,
who have significant malrotation
will be picked up within
the first month of life.
01:11
And usually,
if they're going to be symptomatic,
they'll be picked up within
the first year of life.
01:16
So if you're a medical student,
and you're watching this now,
and you've not been diagnosed,
don't worry about it,
you're not going to have any problems.
01:24
60% of the babies who do
have symptomatic disease
will have some other
congenital anomaly.
01:31
So if this is associated with a
variety of other genetic problems,
and also some developmental
problems that may be related
to the failure to
rotate appropriately.
01:45
For example,
a congenital diaphragmatic hernia
where they just don't have complete
development of the diaphragm,
and you have the bowel pressing
up into the thoracic cavity.
01:56
So for the pathophysiology,
let's look at this because
this is impressive in terms
of all of the contortions
the bowel will go through.
02:03
The overall mechanism, what's driving
this is not completely understood.
02:08
All we can do is say this
is what is known to happen.
02:12
There's clearly in many
cases a genetic basis,
particularly in those babies who
have other congenital abnormalities.
02:20
So normally, the loops of bowel start
developing outside of the abdomen,
that happens as a result of
the elongation of the bowel,
along the umbilical
cord into the yolk sac.
02:35
We have to actually if
you think about it expand
from about millimeters of bowel
initially in the developing fetus,
to something it at full length is going
to be about 7 meters of small bowel
and 1.5 meters of large bowel.
02:52
In order for this to happen, you have to
have some elongation, so a lot of growth.
02:57
It's protruding outside
of the abdominal cavity.
03:00
And then at some point,
it starts to rotate.
03:03
It's about a 270 degree
rotation counterclockwise,
as you look at the
umbilicus counterclockwise,
that allows them the small bowel to loop
around and underneath the larger bowel.
03:17
And eventually you're going to
have the gastroduodenal junction
with the ligament of Treitz tacked
up into the left upper quadrant
and the cecum tacked down
into the right lower quadrant.
03:31
And that gives us the final
confirmation that we're used to seeing
when we do abdominal dissections
or just anatomical dissections.
03:41
So there can be varying
degrees of malrotation,
this entire convoluted process.
03:47
What's being shown here
is complete non rotation.
03:51
The small bowel sits completely over
on the right side of the abdomen
and the colon sits
completely on the left side.
03:58
And the mesenteric vessels are splayed
out, as you see there.
04:04
The cecum in a incomplete
rotation kind of sits mid abdomen
just underneath the epigastrium.
04:10
So that's a partial malrotation
that is tethered in place.
04:15
So instead of having that tethered
in the right lower quadrant
in the normal rotation,
it's tethered into midline
with the lads bands,
so fibers connective tissue
and the cecum sits up there.
04:29
As part of this
malrotation process,
you may actually
twist the mesentery.
04:34
It's not developing
appropriately and it may become
captured up into these loops of bowel
that are not spinning appropriately.
04:42
And when that happens,
you have a volvulus.
04:44
You will have compromised
of the vasculature
to various portions
of the bowel.
04:49
So the mesentery
becomes twisted.
04:51
As a result of that you
can have ischemic bowel
or a completely obstructed small bowel
is part of this tied intestines in knots.
05:01
So the clinical
presentation will depend
on whether you have a partial
malrotation or a complete malrotation.
05:09
And depending on whether
you've compromised vasculature
or you have twisted the bowel and
actually tied it up on itself.
05:16
As I've already pointed out,
most of you are most of the people who will
have this will be completely asymptomatic.
05:23
And they would only be diagnosed
when they go to surgery, for example,
for something happening
otherwise in the abdomen.
05:29
There may be
duodenal obstruction.
05:32
So many of the times with
that partial malrotation,
the duodenum is compromised,
and you will not have
good gastric emptying.
05:40
As a result of that,
you'll frequently bilious vomiting,
forceful bilious vomiting as a
result of that duodenal obstruction.
05:50
Sometimes, if the obstruction is
more proximal to the ampulla of Vater
you won't have any
bile within that.
05:58
So besides the bilious vomiting,
you will also frequently
have abdominal distension.
06:03
There's food not moving through
the GI tract appropriately
as a result of the volvulus.
06:10
Late signs when there's
very symptomatic disease
can include any of the things
you would expect as you are
infarcting or otherwise
damaging the GI tract.
06:19
So you may have hematochezia,
bright red blood per rectum.
06:24
You may have hematemesis,
you're vomiting blood.
06:27
As a result of blood loss, and
malabsorption, the baby may be hypotensive.
06:33
As a result of the hypotension
and the blood loss,
the baby may become diaphoretic,
and clearly tachycardic.
06:39
So these are all kind of secondary to
the loss of blood and/or the obstruction.
06:47
We've changed from a
baby to a young kid.
06:50
In this particular case,
this was not as severe, a malrotation.
06:55
So there is more of a midgut volvulus
that appears later on in life,
early years 7, 8,
9 or into the teenage years.
07:05
There may be vomiting that's associated
with this as the bowel becomes obstructed.
07:10
There will be failure to gain weight
because there is malabsorption.
07:14
The baby may or the young adult
may have chronic diarrhea,
and there will clearly
be abdominal pain.
07:20
The diagnosis is made
on a variety of imaging
and clinical evaluations.
07:27
So the classic study that is performed
to look at this is an upper GI series.
07:34
So we put in barium,
or we have the patient ingest barium,
and then we follow that through
the early portions of the GI tract.
07:43
One, we want to rule out
that there's no perforation.
07:46
So if we have ischemia, we have an
injury, we may have perforated,
that's a surgical emergency.
07:53
In this particular case,
what we're seeing is a double-bubble sign.
07:56
So we're seeing on the right hand side, a
big bunch of barium that's in the stomach,
and then it's coming
out through the pylorus.
08:03
And the proximal duodenum
has kind of a bubble.
08:06
And then there's a narrowing,
and then there's a more distal bubble.
08:10
That's the double-bubble sign.
08:12
And that narrowing in between is
where we've malrotated the valve.
08:17
The upper GI series,
they said as the gold standard
when the patient is
hemodynamically stable.
08:23
So the ligament of traits.
08:25
Remember, we talked about
the duodenojejunal segment
being tethered into the left upper quadrant
that's through the ligament of Treitz.
08:32
If that sits to the
right of midline,
and we can see that on
various imaging series,
then we know that we
have a malrotation.
08:43
The duodenum may also very frequently
have a classic corkscrew appearance.
08:47
And this kind of makes sense if you think
about this basically wrapping on itself.
08:52
And that indicates that we also have a
volvulus, the bowel is tied up in knots.
08:58
What do we do about this?
So clearly, if it's really
severe and symptomatic,
we need to give
fluid resuscitation,
we need to give
intravenous antibiotics
because there's probably
some degree of bowel necrosis
and we have GI flora
leaking into the perineum.
09:13
We want to keep the baby or
the young kid completely NPO
that means Nils per os for
the Latin speakers out there.
09:22
So nothing by mouth, and we clearly
want to do a surgical correction.
09:29
For very healthy children
with no bowel ischemia,
the mortality is near zero.
09:34
And in fact,
as I already intimated,
you can have this and not be symptomatic
at all for your entire lifetime.
09:42
But with greater severity of the
malrotation and with volvulus,
and with infarction,
the mortality will clearly increase.
09:51
So if we have
intestinal necrosis.
09:54
If the baby has to be born early
because of the maldevelopment,
if there are other associated
congenital anomaly,
the incidence of
death will increase.
10:04
Usually surgery
does pretty well.
10:07
And patients that
need to go to surgery
usually will survive if there's
about a 3-9% even after surgery.
10:16
With that we've covered
bowel malrotations.