0:00

Today we're gonna be talking about, uh,

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genital urinary anomalies in the pediatric population.

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So I'm gonna go ahead and share my screen and hopefully you all will be able to,

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um, see my first slide up there. Pediatric genital urinary disease. We can,

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you're good to go? Okay, great. It's a big topic and we've only got an hour,

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so I'm gonna move as quickly as I can.

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I'm gonna start out with the urinary tract,

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and then hopefully we'll have time to get to the genital tract as well. Um,

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so our objectives for this, um,

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session are to look at some real life cases and talk about things that are

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frequently encountered. We'll also discuss some rarities, but, uh,

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focus on the common and, uh, we're gonna dip into embryology.

0:43

I know embryology is not always everyone's favorite topic, uh,

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but it really helps a lot to understand what's happening in the embryo and the

0:51

fetus in order to understand the, uh,

0:54

genital urinary anomalies that are frequently first identified in the newborn

0:58

period and even, um, prenatally. So,

1:00

antenatal hydronephrosis is the number one indication, um,

1:05

for ultrasounds after birth. And, uh, so we will follow up,

1:10

um, on some of those embryology questions. And then, uh,

1:14

I wanna emphasize over and over during this lecture that, uh,

1:17

urine is moving down a one-way street.

1:19

So almost all of our problems can be identified when we see disruption of that,

1:24

uh, one-way traffic of urine. So, uh,

1:29

moving along, we're going to, um, look at cases of antenatal hydro nephrosis,

1:34

and we're gonna look at some of those embryologic anomalies and even, um,

1:38

some associated cases that start out as ventral wall defects or

1:43

failures of the ventral fold to close.

1:46

So this is a fetal mr image of a bladder outlet obstruction,

1:50

a lower urinary tract obstruction, and you can see, um,

1:54

this really expanded bladder and posterior urethra.

1:58

This turned out to be a case of posterior urethral valves, but, uh,

2:01

we're gonna be looking at, uh, cases like that,

2:04

upper and lower areas of obstruction. So just, um,

2:08

why is it important to be able to identify these things early? Well,

2:11

it turns out that prenatal hydro necrosis is something that's very common.

2:16

It's a very common cause of all prenatal abnormalities.

2:19

It's also a very common cause of, uh, you know,

2:23

the ultrasound imaging that we do after birth.

2:25

We can also see it with fetal MRI as well as prenatal ultrasound. And, um,

2:29

there are cases now where we're doing intrauterine intervention.

2:32

So if there's a bladder outlet obstruction, for example, you can place a shunt,

2:36

which will decompress some of that fluid,

2:38

and there's been variable success with that intervention.

2:41

There are also amnio infusions. So if the fetus doesn't void, then the, uh,

2:46

amniotic fluid gets swallowed, and now there's no more amniotic fluid,

2:50

it's not coming back out. And sometimes we can infuse, uh,

2:54

supplemental amniotic fluid, uh, to help the fetus. So, uh,

2:59

what we're gonna be doing in most of these cases, prenatally,

3:03

is we're gonna be looking at the dia, uh, the diameter of the renal pelvis,

3:06

and these are some of the numbers that people frequently cite as cutoffs.

3:11

And, uh, as you can see, the number changes around the 33 week period.

3:15

Interestingly,

3:16

the 33 week period is also a really important time in terms of whether the

3:21

lungs are, um,

3:23

undergoing net absorption of fluid or net secretion of fluid.

3:27

So we can see a lot of, um, corollary effects in the pulmonary,

3:32

uh, the fetal pulmonary system with, uh, the urinary abnormalities.

3:37

And that ends up being a really important determinant of outcomes.

3:41

So this is a, a two side-by-side. Images of prenatal ultrasound,

3:45

if you're disoriented, you don't commonly look at these, uh, images.

3:48

Always look for the shadowing from the fetal spine.

3:51

And you can see the shadowing here, so you know where posterior is.

3:54

And then on either side of that spine, in the retroperitoneum, of course,

3:58

are the fetal kidneys.

3:59

And you can see measurements taken of the renal pelvis here.

4:02

This is a fairly common thing to see a little bit of fluid in the renal pelvis.

4:06

Sometimes our obstetrical colleagues will refer to this as ectasis. Um,

4:11

postnatally we would say pelviectasis. Uh, that's not a concerning finding.

4:15

Here we can see a little more asymmetric dilatation.

4:18

This is kind of a traditional transverse, or, you know, we might say axial view,

4:23

where you can see that fluid in the renal pelvis.

4:26

And then this is more of a coronal view.

4:27

You can identify the splitting the bifurcation of the great vessel,

4:31

so that's too much fluid,

4:33

that's abnormal and asymmetric renal pelvic dilatation,

4:37

and that's something that's gonna be followed up after birth.

4:39

Here's the corollary of the fetal MRI. Um, this is, uh,

4:44

the maternal body is upright, but the fetus is in, uh,

4:48

cephalic presentation, so that's why it's upside down.

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And you can see bilateral, uh, renal pelvic dilatation,

4:54

but much more severe on one side than the other.

4:57

It can be sometimes difficult to determine what side you're on, but, um,

5:01

here's the stomach so we can be pretty confident. The left kidney,

5:04

we've got cile and pelvic dilatation there.

5:07

And then here's what it looks like on an axial image of the fetal, uh,

5:11

body on MRI. So here's the spine, of course.

5:14

Here's a renal pelvic dilatation here, some renal pelvic dilatation here,

5:19

and then this massively dilated, uh, ureter as well.

5:23

So we know there's some distal obstruction.

5:25

So what happens with all these cases of antenatal hydronephrosis? Well,

5:29

you know, many of them don't mean anything at all.

5:32

So we try not to get too worked up.

5:34

We do follow up cases that we identify as abnormal, but a lot of them, um,

5:39

end up being normal and it's a smaller subset that we have to end up doing

5:43

things for postnatally. The, the fluid in the renal pelvis is gonna move,

5:48

you know, larger and smaller during gestation. And, uh,

5:51

anytime we see bilateral concern for obstruction,

5:55

that's gonna have worse outcomes. Obviously,

5:58

complete bilateral obstruction, uh, can be fatal if, uh,

6:03

the lack of voiding and the anhydrase leads to

6:08

pulmonary hypoplasia in the fetus. So, uh, we do look at,

6:12

um, the, those renal pelvic diameters,

6:16

and we do know that there is some correlation that if you see it dilated

6:21

earlier to a greater degree,

6:23

then those are the patients who are more likely to need intervention. Uh,

6:27

there's a lot of reasons for that dilatation. In addition to the vast majority,

6:31

which are just physiologic,

6:33

we have obstructions in the upper urinary tract in the lower urinary tract.

6:37

We can have lesions of the ureter themselves, including ureter roll atresia.

6:42

We can have duplicated systems where there's a ureter seal at the bladder

6:46

blocking one of the duplicated ureters. Uh,

6:48

we can have valves both posterior and anteriorly in the urethra.

6:53

You can have strictures, although those are certainly more common, um, in the,

6:57

uh, postnatal population, especially post-traumatic, uh,

7:02

children often undergo, you know, so-called saddle injuries. So, um, you know,

7:06

if it's non-obstructive, there can still be dilatation,

7:09

and that can be due to repeated, uh, pathologic reflux.

7:13

That can be due to a congenital mega ureter or some of the syndromes that we

7:17

see, uh, prune belly syndrome, sometimes called eagle Barrett. And, um, then,

7:22

uh, cloacal extrophy, which is a severe failure of the ventral wall to close.

7:27

And bladder extrophy, which is a slightly more mild, um,

7:30

abnormality on that spectrum. Um,

7:32

bladder extrophy is frequently nonsymptomatic,

7:36

and there are not any ureteral or renal imaging findings because it tends to not

7:41

obstruct the flow of urine. Uh, cloacal extrophy is, uh,

7:45

slightly more complicated and can have problems, uh,

7:48

because there's an associated, uh, um, falle.

7:52

So why are we doing all this diagnosis? Well, it's, you know, to treat.

7:57

And a what is our goal with treatment?

7:58

You might think it's to fix the kidneys or to preserve the kidneys,

8:02

but that's actually our secondary goal. Our primary goal is the lungs. Because,

8:06

you know, if you're born without kidneys or if you're born with pretty weak and

8:11

incompetent kidneys, we can fix that. We can put you on dialysis,

8:16

we can find transplant kidneys for you. I mean, I don't,

8:19

I don't wanna suggest that it's simple, but it's possible.

8:22

But if you're born without lungs or without functional or

8:27

sufficient lungs, there's not much we can do for you. There's no such thing as,

8:31

uh, neonatal bilateral lung transplants that's, uh,

8:35

not part of a modern medicine, at least not right now.

8:37

So we need to make sure your lungs develop properly because pulmonary hypoplasia

8:42

and severe pulmonary arterial hypertension is, um,

8:47

devastating and can be fatal for many, um,

8:50

cases of congenital urinary tract anomaly. And as I mentioned earlier,

8:55

failure of the kidneys to function or failure of the kidneys to be able to

9:00

pass urine because of a blockage leads to low or absent

9:05

amniotic fluid, which means no swallowing,

9:07

none of that fluid going in and nourishing the lungs and helping them grow.

9:11

And so our problem is really lung. Uh,

9:15

we are gonna follow up these cases first prenatally and then anti, uh,

9:19

right after birth. And then, um,

9:21

sometimes we'll do fetal MRI if we suspect there's a syndrome.

9:24

If we suspect that there's a little bit of an,

9:27

a lack of clarity of whether it's urinary tract dilation or GI tract dilation,

9:32

a big loop of bowel and a big ureter can look similar. Um,

9:36

and then I mentioned there are rare, uh, interventions.

9:40

There has been some discussion in the urologist community about using

9:43

antibiotics prophylactically at birth, and that's controversial. Uh,

9:47

but certainly we're gonna follow up with more imaging and, uh, you know,

9:52

when do we do that? Um, one of the things is we,

9:55

the fluid levels in fetuses,

9:57

the overall fluid status can be quite variable,

10:01

and there's a risk of both dehydration and fluid overload. Um,

10:06

so we try not to image right after birth,

10:09

and that's always a struggle as radiologists.

10:12

I think that you'll find that if you indicate something on prenatal

10:16

ultrasound, um,

10:18

then there's gonna be a temptation or a desire for the clinician to get that

10:22

follow-up postnatal ultrasound on day zero of life, day one of life boom.

10:26

And we really try and encourage our colleagues to wait just a little bit until

10:31

we can get to a more, um, normal fluid status,

10:36

and then we can accurately assess whether there's hydro necrosis. We don't want,

10:40

you know, false positives and false negatives. So, uh,

10:43

we will image in cases of severe obstruction right away, but if it's, you know,

10:48

mild or mild to moderate antenatal hydronephrosis,

10:51

no harm in waiting a week or two.

10:56

Um, and then, you know, what, what ends up happening with these kids? Well,

10:59

you know, there's, there's variable outcomes, of course,

11:02

that's a big study from urology in 2011 that looked at, uh,

11:07

15, nearly 1500 kids who had had antenatal hydro

11:12

necrosis identified. And in this sample population, uh,

11:16

more than half were normal. And then, uh,

11:18

you can see the breakdown of what the outcomes were.

11:21

So very commonly vesco ureteral reflux,

11:24

which also can be normal. And then, um,

11:28

some obstructions at the, uh, UPJ and UVJ, and then a,

11:31

a very small percentage of other problems like valves, ectopic, uh,

11:36

structures and ureteral seals, uh, syndromes being the rarest. So, uh,

11:41

the vast majority of cases,

11:42

70% are either normal or we identify vesco

11:47

ureteral reflux. And as I'm gonna talk about later, uh,

11:51

it may be that we're not helping much by finding some transient, you know,

11:55

asymptomatic vesco ureteral reflux in a newborn.

11:59

So there's a lot of systems to grade hydronephrosis. Uh,

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the original system was described by the Society for Fetal Urology.

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It's a system that's still used in many places around, uh, north America,

12:11

at least, I can't speak as confidently about Europe, um, or,

12:15

or elsewhere in the world. But, uh, it's the original system and it's still, um,

12:21

you know, preferred by many urologists. Now, there are newer systems.

12:24

There's one that looks at the anterior posterior diameter that APD and really

12:28

emphasizes that integrates it sometimes in combination with this SFU Society

12:33

for fetal Urology system. And then there's also the newest system,

12:37

the urinary tract dilation, the UTD system. And, uh,

12:41

that has been accepted and implemented at a number of places,

12:44

but it certainly has not completely replaced this traditional, uh, system.

12:49

And, uh, just in my own, uh, part of the world here in the Midwest, uh,

12:54

United States, we're still using this, um, SFU system quite a bit.

12:58

And it really is variable based on what your urologists want you to use.

13:02

So I'm not gonna spend a lot of time talking about the pros and cons of those,

13:05

uh, because we have a lot to get to today.

13:07

But just be aware there are other systems, even if you know,

13:10

you have learned this traditional, um,

13:13

original grades 1, 2, 3, 4 SFU system. So here, the,

13:18

here are the grades. Um, technically grade zero is, uh, a thing,

13:22

but I don't know many people who will diagnose grade zero because, uh,

13:26

we call that normal. So please just say normal. And then, uh,

13:29

here's some examples. Um, this is a normal kidney in a newborn, uh,

13:33

might look a little bright to you, um, if you're,

13:37

if you're used to scanning adults, but, uh,

13:39

this is normal for a neonate or premature, uh,

13:42

infants can have even brighter, uh,

13:45

echogenicity on the renal ultrasound at birth. Here's grade one,

13:48

just a slight splitting, an opening up of that, uh, renal pelvis,

13:53

but we certainly didn't see any lyes.

13:55

And now we're seeing just a little bit of the, uh, major CAEs. And, uh,

14:00

that's gonna continue, as you might expect,

14:02

from the major CAEs to the minor CAEs, uh, in grade three.

14:07

And then finally, the most severe, uh, grade,

14:11

grade four in this SFU system has cortical thinning scarring.

14:15

There's permanent damage that's happened to the kidney.

14:17

So this is of course the most concerning. And in some ways,

14:21

we're a little too late here, uh, that I don't mean to suggest there's no hope,

14:25

but permanent damage has already occurred in grade four. So, uh,

14:30

how are we gonna work up these cases? Well,

14:31

obviously normal cases don't need any workup.

14:34

Some people would say grade one antenatal, you know, hydro nephrosis,

14:38

we're not always grading. It doesn't need to be worked up.

14:40

And you saw those numbers. So many of those cases are normal,

14:43

but we typically follow up, uh, the antenatal, and if we see it at birth,

14:47

most people will follow that up at least one more time. In the past,

14:52

it might've triggered a referral for VCUG, because, you know,

14:55

we see that a lot of these cases of hydronephrosis are caused by, uh,

15:00

vesco ureteral reflux. Now,

15:02

do we need to find every case just because it's happening? Well,

15:05

probably not because there's such a thing as, you know, benign reflux,

15:09

transient limited, benign reflux, and, um,

15:12

the management of those cases has changed. And so, uh,

15:15

increasingly imaging centers, including my own,

15:18

are changing our imaging to kind of reflect the management.

15:21

If urology's not gonna treat benign transient reflux,

15:25

we're not gonna do A-V-C-U-G to find it. So, you know, grade one hydronephrosis,

15:29

we don't do, uh, VCU gs unless there's some other indication, um,

15:33

grade two or, uh, kind of, uh,

15:37

persistent reflux. We will do A-V-C-U-G. And, uh,

15:41

certainly with grades three and grade four,

15:42

we're gonna look not just for reflux and structural abnormalities,

15:46

but we're gonna look for function.

15:47

And that's what the nuclear medicine studies can do for us. We use MAG three,

15:51

uh, pretty frequently here. Um, so when we do A-V-C-U-G,

15:56

we're looking for, you know, reflux, which can be benign.

15:59

We're looking for structural anomalies like a ureter seal.

16:01

We're looking for abnormalities of the urethra in males, um, you know,

16:06

hard to see much in females in the urethra. And then, uh, we're gonna do, um,

16:11

some, some functional physiologic imaging to,

16:14

to try to specify what the kidneys are still able to do.

16:18

The anatomic appearance and the physiologic function often go together,

16:23

but sometimes they don't. For example,

16:26

we will see abnormal kidneys that seem to have a lot of residual normal

16:31

parenchyma in the prenatal imaging after birth.

16:35

We'll do a functional study and find, you know, there's kidney there,

16:38

but it's not actually working.

16:39

So we can't assume that anatomy equals physiology. And then,

16:44

uh, we're gonna look at, you know, bladder outlet obstructions, of course, and,

16:49

uh, we're gonna try to see if we can identify sometimes the cause of downstream

16:54

abnormality. So severe, persistent and,

16:58

and refractory hypertension in the newborn population is much more likely

17:03

to indicate, uh, an abnormality in the kidneys or in the renal vessels.

17:07

In the older pediatric population,

17:10

it's not really as much of a good predictor because there's so much obesity in

17:14

that population, and that's a much more likely cause of hypertension. Um,

17:18

the prophylactic antibiotic therapy that I mentioned earlier, that's no,

17:23

no longer a consensus view among urologists. And in fact,

17:26

even if there's a, um, urinary tract infection,

17:30

a first time urinary tract infection in a young child, um,

17:34

does not automatically trigger antibiotics, does not automatically trigger, uh,

17:38

the VCUG, um, in some of our urology, you know,

17:43

viewpoints.

17:44

So there's some controversy about how quick our trigger finger should be on some

17:49

of these things because it's, it's not a simple matter getting a, um, getting a,

17:53

uh,

17:54

catheterization for avoiding cysto urethrogram is not a pleasant experience for

17:58

many children. And unfortunately,

18:00

if their children who have already been previously traumatized,

18:03

it can be quite upsetting. And, uh, you know,

18:06

parents obviously don't want to see their child suffer or even be distressed.

18:10

And so we try not to take the VCUG study too lightly.

18:14

It is an invasive procedure, um, and we don't wanna do it unnecessarily.

18:19

So a lot of these patients will improve over time,

18:21

those grade ones and some grade twos, the grade threes and four, uh,

18:26

are gonna get intervention. So, um, what about this vesco ureteral reflux?

18:31

Um, what is the way to deal with it? Well, you know,

18:34

first we need to know if it needs to be dealt with. Is it, is it benign?

18:37

Is it incidental? Is it asymptomatic? A lot of these cases will be outgrown or,

18:41

you know, um, only transient.

18:44

But for the persistent or severe types of vesco ureteral reflux,

18:48

there is going to need to be some kind of treatment.

18:50

And as you can see in these images here, um,

18:53

the angle of insertion of the ureter into that detrusor

18:58

muscle into that bladder wall is really important. The, the steeper the angle,

19:02

um, the more muscle there is surrounding the distal ureter,

19:06

the more it can prevent reflux. The more of a 90 degree angle.

19:09

With the ureter coming almost at a, at a, you know,

19:14

transverse to the wall of the bladder, um, there's not as much muscle.

19:18

And so one treatment would be to do a reinsertion and try and

19:23

achieve, for example, an angle, something more like this that you see here,

19:27

rather than this right angle. Um,

19:30

another option that's been used by various, uh,

19:32

urology groups is to inject some sort of inert substance.

19:38

And, uh, we, we call it dfl, um, the one that's used, um,

19:42

where I practice,

19:43

and it can narrow that outlet of the ureter at the

19:48

bladder wall. Here you can see some being injected,

19:50

and it can also help with reflux, uh, that's used variably.

19:54

And the indications for one or the other,

19:57

or the practice of using one and not the other is highly variable depending on

20:01

location. So you'll,

20:02

you'll want to get to know your urologist and find out what their practice is.

20:05

Uh, but both treatments have been used to prevent, you know,

20:08

pathologic or symptomatic vesicular ureteral reflux. Obviously,

20:12

if there's a ureter seal that's gonna need to be treated and removed or taken

20:17

down here, you can see a filling defect in the bladder. Uh,

20:21

a large ureteral seal, typically at the location of ureteral insertion. Here,

20:25

you can see even after the bladder has been progressively filled,

20:28

there's a large area of filling defect. In this case,

20:31

this ureteral is low and central. So we would concern about,

20:35

we would be concerned about a CECO ureteral,

20:38

which is just a ureteral that falls into the bladder outlet and can cause

20:42

bladder outlet obstruction. So it's, it's more symptomatic,

20:46

it's more concerning and needs to be treated with more, you know, more urgency.

20:50

Here's an ultrasound, postnatal ultrasound example of a ureteral seal.

20:54

You can see this thin membrane surrounding a large amount of fluid centrally

20:58

within the bladder. And, uh,

20:59

that causes obstruction typically at the uretal ureteral, um,

21:04

insertion to the bladder, but as I say, it can also block the bladder outlet.

21:10

Um, when we see ureter seals,

21:12

that automatically points us to a duplicated system.

21:16

It's not necessarily associated,

21:18

but it's frequently associated with duplicated system. So we're gonna,

21:21

of course, wanna look at the kidney,

21:22

and we're gonna wanna look not just for duplication,

21:25

but for obstruction because, uh, of the ureter seal.

21:28

So here you can see variable amounts of fluid filling the upper and lower

21:32

moieties of this kidney. And you can see this tortuous dilated ureter, um,

21:37

associated with that left kidney or associated with one part of that left

21:40

kidney. This was a completely duplicated system,

21:43

and it's the upper pole that traditionally has been identified as obstructing.

21:48

The lower pole can reflux,

21:50

but the upper pole will be the one that leads down to that ureteral and

21:54

obstructs. And over time, if left untreated,

21:57

it's the upper moiety of the kidney that because of chronic

22:02

obstruction, will develop cystic dysplasia and we'll often scar down.

22:05

So if you're seeing a, an older child for the first time,

22:08

they may only have a tiny bit of echogenic tissue residual scar

22:13

up at that upper location where the upper moody used to be. Um,

22:17

here's an early image.

22:19

You can see that there's asymmetric dilatation between the upper and lower

22:23

moieties, uh, but there's still some renal tissue around that,

22:26

so we're not yet at that point of cystic dysplasia. And, uh,

22:30

here's the corollary, uh,

22:33

VCUG image where you can see reflux, um,

22:36

coming up this ureter and going into what's been sometimes described as a

22:41

drooping lily. This is the drooping lily sign. And in other words,

22:45

we're only filling the lower moiety.

22:47

There's presumably a collecting system that matches that,

22:51

that would've been for the upper part of the kidney,

22:53

but it's not lighting up here because it's communicating via an entirely

22:58

separate ureter. Uh, we also see on this patient a large ureter seal.

23:03

And so presumably the ureter seal is associated with the ureter going to the

23:07

upper moty. Uh,

23:08

but we can't see that because there's no contrast refluxing either there's,

23:13

there is no reflex or that ureteral is preventing reflux.

23:18

So, uh, when we see duplicated collecting systems, um,

23:22

we look for all of these things. We look for obstruction,

23:25

we look for ureter seals,

23:27

we look for that upper moiety to maybe show signs of scarring or damage,

23:31

and then we want to identify the insertion of those two ureters down on the

23:35

bladder. And the, um, thing to remember is the Weigert Meyer rule.

23:40

This tends to come up on board exams and, uh, other, you know, quizzes, uh,

23:45

which, which ureter is gonna insert where, and it's that upper ureter,

23:50

that's ectopic, that's abnormally inserting.

23:53

It's the upper ureter that's obstructed,

23:55

it's the upper ureter associated with the ureter seal and being ectopic,

24:01

not orthotopic, not where it should be, but ectopic,

24:04

it's traditionally gonna be lower,

24:06

more inferior and medial to the normal ureter.

24:09

So you've got your normal ureter mirror image of the, you know, other side,

24:13

which is presumably, uh, a single collecting system.

24:16

And then medial and inferior to that, you've got your secondary ectopic ureter.

24:22

So these are all things to bear in mind when you're doing your renal ultrasound.

24:26

And, and VCUG imaging, here's an artist illustration of the two ureters. Uh,

24:31

the one that's dilated and ex tortuous is connected to the ureter seal.

24:36

And you can see here it's lower and medial to this orthotopic normal ureter,

24:41

and that's the upper pole.

24:42

Here's a nice VCUG image showing both systems at once. So in this case,

24:46

there was not an obstructing ureteral. And, uh,

24:50

occasionally we will see reflex into both systems.

24:52

So you can imagine an entire renal parenchyma around both of

24:57

these systems. And if you only looked at the bottom one by itself,

25:01

you might call it a drooping lily,

25:03

but now we can see the upper moiety and the lower moiety.

25:06

And then for comparison purposes, this left side is singleton.

25:11

Uh, here's a lily on radiography compared to A-V-C-U-G.

25:15

So you can see where the, the name comes from. And, uh,

25:19

here is an ultrasound, or I'm sorry,

25:22

A-V-C-U-G image of the bladder.

25:25

And you can see just ever so faintly down here,

25:29

two different dense lines coming up from the bladder.

25:33

So we're getting a very subtle indication of a duplex collecting system.

25:38

And then up here you can see there's this lower moiety and then a second ureter

25:42

going up to the upper moiety. So sometimes the findings can be very dramatic,

25:47

sometimes less so. And here's, uh,

25:51

a further image of this patient with duplicated collecting systems. Uh,

25:56

here's a transverse, um, I'm sorry,

25:58

a sagittal image trying to identify the point of insertion of the ureter.

26:03

And, um, just, uh,

26:05

this is an illustration when the insertion is not only ectopic,

26:08

but it's not on the bladder at all. In fact,

26:10

the ureter can frequently insert on the bladder neck or the urethra,

26:15

which you might have a patient present with continuously being wet even after

26:20

they have, you know, um, been trained to use, you know,

26:24

bladder control. Um, or it can insert, uh,

26:28

on the vagina in females also would present as continuously being wet,

26:33

um, in males, uh, uncommonly. But we do see it,

26:37

it can insert on the seminal vesicle and, uh,

26:40

that introduces bacteria into the genital tract.

26:44

So those patients can present with, um, oras and epididimitis.

26:49

Now,

26:49

we frequently think of a teenager or a young adult with epididimitis as having a

26:54

sexually transmitted disease, GCal infection, and that being the cause of,

26:58

of their abnormality, but rarely, especially in young children who, you know,

27:03

we hope don't have sexually transmitted diseases, um,

27:07

it can be because of an ectopic ureter that's allowing urine to get into the

27:12

genital tract and, uh, potentially cause that infection, uh, that, that,

27:17

you know, you might first identify on a, a testicular scrotal ultrasound.

27:22

So we're gonna skip ahead a little bit to some embryology.

27:25

We're gonna talk about urinary tract dilatation, um, because of obstruction.

27:30

And, uh, this is, uh,

27:31

just a reminder that we have different structures coming together. Uh,

27:35

we've got the meso nric duct, and then we've got the renal blastema.

27:41

And those two different structures have to merge with the ureteric bud.

27:46

And, uh, in order to have a fully functional system,

27:49

there has to be not just fusion of the structures,

27:52

but there has to be a cannulation so that the kidney, the,

27:56

the final kidney, can allow the,

27:59

the urine to flow freely into the ureter, into the bladder.

28:03

So if there is never a complete fusion of those structures, or if they fuse,

28:09

but don't open, uh,

28:10

you're gonna have some type of UPJ obstruction ranging from complete

28:15

obstruction to narrowing stricturing and, and all along that spectrum.

28:20

So UPJ obstructions can cause variable levels of, um,

28:24

abnormality and, and, uh, hydro necrosis,

28:27

and they will present at different ages, so the more severe the obstruction,

28:30

the earlier they present. But we will see young adults, teenagers,

28:35

first time presentation with hydronephrosis,

28:38

and it turns out they have a mild UPJ obstruction. And, uh, you know,

28:43

if you lose some of those signaling factors,

28:45

you get failure of complete fusion of the structures. This is a,

28:50

a physiologic study, a, uh,

28:52

nuclear medicine test showing a failure of the contrast

28:57

agent to be able to pass out of the kidney.

28:59

And you can see the asymmetry and how much, uh, uptake there is first,

29:03

and then how much excretion. So, uh,

29:06

a severe asymmetry between right and left sides.

29:08

And then even when we get down to the excretion, the later phases,

29:12

even after the administration of Lasix, you can see there's a significant delay.

29:17

So, uh,

29:18

nuclear medicine studies can help us to identify how severe the obstruction

29:23

is, how responsive the kidney is to Lasix, how much delay there is,

29:27

or if it's a complete obstruction and there's zero excretion.

29:31

And of course we can measure, you know, half-lifes and, um, time to excretion.

29:36

So, uh, this is, this is, you know,

29:38

what's so valuable about being able to combine the anatomic and the physiologic

29:42

imaging? So just to show how these things can develop over time.

29:46

The kidney might start out normal, looking like a, a newborn, you know,

29:50

admittedly echogenic,

29:51

but normal newborn kidney all the way to this very severe obstruction as it has

29:56

become progressively more severe. And there's been progressive renal damage,

30:01

scarring, cortical thinning over time.

30:03

So this is a case where if we act with urgency

30:08

and if we are accurate in our initial diagnosis, we can prevent a lot of harm.

30:13

Uh, this is not always true, but there is a subset of patients,

30:17

especially those grade three, um,

30:21

patients and some of the milder grade four patients where we can intervene early

30:25

and prevent a lot of damage. Um, the milder cases,

30:30

maybe there's less concern and the very severe cases at birth,

30:33

maybe all the damage has already been done. Here's a, uh,

30:38

a cross-sectional study, obviously postnatal, looking at asymmetric dilatation,

30:43

you can see quite dramatic difference in the thickness of the renal cortex, uh,

30:48

between right and left. And then you can see it's not just renal,

30:50

pelvic and caleal dilatation,

30:53

but also the proximal ureter is quite dilated as well.

30:57

That's a patient with AUPJ obstruction. Here's another example,

31:01

A little bit more distal,

31:02

you can see some of the pelvis has become extrarenal because of the pressure

31:06

dynamic of this obstruction with, uh, pelvic alesse dilatation severe.

31:11

This is obviously grade four. And then here's a, um,

31:15

an example where contrast has been injected. Uh, this is not gonna be, uh,

31:20

an image you would be able to obtain on A-V-C-U-G in a severely obstructed case

31:24

because the contrast can't make it back to the kidney.

31:26

But you can see this massive renal pelvis, uh, completely featureless.

31:31

There's definitely caly seal dilatation there as well,

31:35

but you can't identify discrete CAEs, the fornix of the calyx or any of that.

31:40

It's all expanded. And I, I, I would say almost blown out, you know,

31:44

because of the severe increased pressure and obstruction.

31:49

Here's a less dramatic example. Again,

31:51

this contrast is being injected into the kidney percutaneously, um,

31:55

and showing that focal narrowing, um, at the point of,

32:00

uh, the atresia. And, um,

32:04

in cases of UPJ obstruction, there are various causes.

32:07

We don't fully understand how every case develops.

32:10

We know that it can be the embryo, uh,

32:12

the embryologic process has been disrupted.

32:14

It can be abnormalities because of genetic deletions and mutations of the smooth

32:18

muscle. It can be neurologic abnormalities. There can be, um,

32:23

extrinsic structures. So these wouldn't be embryologic, uh,

32:26

problems with the kidney, but maybe you have, you know, a duplicated IVC,

32:32

uh, or an abnormal position of the ureters that are quite medial,

32:35

and there's pressure from a, from a vessel, um, or some other structure.

32:40

So when it's a case like that,

32:41

those cases can often be treated without urologic intervention. Um,

32:46

but in many cases of true UPJ obstruction,

32:49

a pile of plasty is required that a retic segment has to be removed,

32:53

and then a new anastomosis created

32:56

in a UV J obstruction, of course, the, the,

32:59

the blockage is down by the bladder at the ureteral insertion of the bladder.

33:03

Similar problems, it can be intrinsic to the muscle or the nerve,

33:07

it can be due to the insertion angle of the ureter, or it can be extrinsic, um,

33:11

from abberant anatomy. And of course, we all know of the phenomenon of, um,

33:16

calculi that's typically seen in,

33:19

in a much higher rate in adults than it is in children.

33:22

But older children do tend to get renal calculi in children with, you know,

33:26

abnormalities of calcium and phosphate. Um, so there's various causes.

33:30

Here's an example of the progressive changes. So in 2006,

33:33

this patient had both pelvic and cile dilatation.

33:37

And then you can see it's almost hard to find the kidney in

33:41

2007 and 2009.

33:44

There's progressive atrophy and scarring,

33:47

and what little tissue does remain is very echogenic.

33:50

This is not echogenicity because of the newborn. This is scarring.

33:54

And if we did a MAG three study or some other physiologic function test,

33:58

there would not be a function there. So what's the outcome?

34:02

The outcome of this is, uh, cystic dysplasia.

34:05

And I want to separate that from an MCDK.

34:08

MCDK is an abnormality of development where a renal pelvis never forms from

34:13

the earliest parts of embryology. Renal cystic dysplasia is in response,

34:18

often, not exclusively, but often in response to chronic obstruction,

34:23

so like AUVJ, uh, or AUPJ, um, obstruction.

34:27

And these are, um, going to progressively involute.

34:30

They don't require surgical intervention if we've already identified a lack of

34:35

function. Now the surgical intervention can preserve function,

34:38

it can intervene before we've reached that point of total scarring.

34:41

But once you're there, no surgery is required.

34:44

In the past that might've been excised, that little residual scarred tissue,

34:49

now we just leave it, it doesn't cause problems. There is no, um,

34:53

concern for transformation into any other kind of malignancy.

34:57

That's not always true with multicystic dysplastic kidney. And remember,

35:01

that's a,

35:02

an error in embryology where the kidney never even forms properly that

35:07

can have malignant potential. And so the treatment is different,

35:11

but if it's obstruction leading to cystic dysplasia, uh, we just leave it alone.

35:16

So I'm just gonna briefly go through a couple of other cases so that we have

35:20

some time to look at, uh, the genital tract anomalies.

35:22

Here's a 17 day old who had prenatally diagnosed necrosis.

35:27

You can see pelvis and clocs are dilated asymmetrically on the right side.

35:32

And, uh, when we did a retrograde, um, you know, injection of contrast,

35:36

you can see that the distal nature of the obstruction leads to not just renal,

35:41

pelvic and casal, but also, uh, ureteral dilatation.

35:46

And this was a, uh, primary obstructing mega ureter. Here's a newborn.

35:50

You can already right away on this renal ultrasound.

35:52

C there's some thin membrane in the bladder.

35:54

Maybe you're thinking about a ureteral. I hope you're thinking about a ureteral.

35:58

And not only do we have renal, pelvic and casal dilatation,

36:01

but a very tortuous ureter down by the bladder. Uh,

36:04

so we're thinking about a distal ureteral obstruction, not AU pj.

36:09

Uh, and, um,

36:10

here's some more images of both the kidney and that tortuous dilated

36:15

ureter. And then on VCUG, uh,

36:17

you can see a filling defect in the bladder. And you can see, um,

36:22

this ureter,

36:23

you can see almost this bear paw configuration of dilated pelvis and dilated

36:28

CAEs. And, um, you can see the severe, um,

36:32

obstruction on this mag three study where even, you know, at 40 minutes,

36:36

there's, uh, not really, uh, much passage of contrast.

36:39

So this patient ended up having a ureteral seal and that chronic obstruction had

36:44

led to cystic dysplasia. In fact,

36:47

there was so much pressure in the collecting system that there was a oma in the

36:51

left upper quadrant. So, um,

36:54

didn't reveal itself quite as nicely on this nuclear medicine study, but it,

36:58

there was a collection of urine from a rupture of a calyx. So this was a,

37:03

a very severe blockage. And, uh, also a vesco ureteral reflux.

37:08

Here is a pregnant patient with, uh,

37:12

fetal urinary tract obstruction. Here's the fetal spine,

37:16

and you can see bilateral, uh, abnormalities.

37:20

One looks like a very enlarged pelvis.

37:22

This looks like multiple cystic structures,

37:24

so those could be CAEs with this single image. We also would have to consider,

37:28

could those be cysts? This is, you know, later in the process, cystic dysplasia.

37:33

Uh, but now that we're down here at the, uh, pelvis,

37:37

we see this massive bladder, we're starting to think, well,

37:39

this isn't a ureteral problem. This is a bladder outlet obstruction.

37:43

And of course, on this sagittal view, you can see dilated kidney,

37:48

dilated pelvis, and clocs and ureter and bladder. So, uh,

37:53

confirming our suspicion, there's another, uh,

37:55

view of both the kidney and the bladder and, um, another view here as well.

38:01

And so what we ended up diagnosing in this case, um, was

38:06

that there was a bladder outlet obstruction.

38:08

The right side had already involuted, um,

38:12

and just caused cystic dysplasia. So there wasn't really urine being produced,

38:16

and that's why the dilatation looked asymmetric. So just in summary,

38:21

um, I I wanna remind you that for our grading,

38:26

those milder cases can be followed up a little bit later after birth,

38:30

to wait for that fluid to rebalance. To normalize for severe cases,

38:35

we need to act quickly and, uh, be aware of the way that urologists, um,

38:40

are treating at your institution because there is some variability in how they

38:43

want those kidneys to be graded and what type of interventions they're offering.

38:47

For example, uh, for vesco ureteral reflux, I'm gonna skip ahead.

38:52

In the second portion of our hour,

38:54

I'm gonna talk a little bit about genital urinary disease at the genital tract

38:58

aspect, and, uh, consider just a few of the diagnoses you ought to be aware of.

39:02

So this is sort of the part two. And, um,

39:05

here is a image on a fetal MRI of a 24

39:11

year old who has this bilateral urinary tract

39:15

abnormality in their fetus. And you can see spine here,

39:19

renal pelvic dilatation on both sides, and some dilatation here.

39:24

Now, this is the bladder, but note what's going on here.

39:27

This is the insertion of the umbilical cord.

39:29

So we're seeing pressure in the urinary tract that's actually re canalizing

39:35

the structure that connects the bladder to the cord. In fact,

39:37

that's the way that the early embryo and fetus voids, and I'm,

39:41

I'm talking of course of the UCUs. Now at this point in gestation,

39:45

you can see how large the fetus is. Uh,

39:47

there shouldn't be voiding through the ureas,

39:50

but increased pressure can cause that to remain open. And, uh,

39:54

it can be sort of like a, um, decompressing effect for the bladder. Here's the,

39:59

the bilateral ureters as they're coming off the kidneys, obviously very dilated.

40:03

Here's a picture of just how much pelvic cele expansion there is, uh,

40:08

on this fetal MRI image. And here it is again,

40:12

you can see the bladder here, uh,

40:14

a little bit of urine moving towards the bladder neck,

40:16

but also a significant amount moving through the UCUs and out into the base of

40:21

the umbilical cord.

40:22

So that can be an indicator to us of just how high pressure of a system it is.

40:26

And, uh, here you can see a companion case. These were both the same diagnosis.

40:31

We've got massive expansion of the collecting systems,

40:34

massive expansion of the bladder. This is a bladder outlet obstruction.

40:37

This was posterior, uh, urethral valves.

40:40

And here's the classic image that's been used traditionally to describe a

40:45

keyhole appearance because we're seeing a dilated bladder and also a dilated

40:50

posterior urethra.

40:52

So sometimes you'll see that listed keyhole bladder in

40:56

posterior urethral valves. Just like with AUPJ obstruction,

41:00

the valves can be completely obstructing,

41:02

which is gonna cause more severe changes earlier,

41:05

or they can be incomplete obstructing. And rarely,

41:09

you can see pediatric patients present quite late in life with

41:14

posterior urethral valves, you know,

41:16

in their teenage years that have been just obstructive enough to

41:21

cause damage,

41:22

but not quite obstructive enough to make the damage so severe that they were

41:26

having symptoms. So it's a kind of a gradually progressive thing.

41:30

They may show up at age 12, 13 years old, you scan their kidneys,

41:33

they've never been scanned before, and they've got all this renal scarring,

41:36

and it's because of this chronic partial obstruction. Uh,

41:39

here's an example of severe hydro nephrosis in a older patient who presented

41:43

with posterior urethral valves. Here's a, uh, avoiding cysto urethrogram,

41:48

which shows a very abnormal bladder.

41:51

Note how elongated this bladder is. Note the irregularity of the bladder wall.

41:56

And, uh,

41:57

that sort of undulation or trabeculation is the sign of chronic

42:02

obstruction. So in, in, uh, many patients with congenital, um,

42:07

anomalies of the spine, they can end up with neurogenic bladder,

42:12

and that will also be elongated, dilated trabecular,

42:15

because the bladder is basically contracting against a closed door.

42:18

And so the bladder muscle becomes very abnormal.

42:21

In some cases it becomes too strong, but, but it's, it's strong in a disordered,

42:26

disorganized way. Same thing here.

42:28

The bladder is contracting over time against a closed door,

42:31

and the muscle develops in unhelpful ways and it changes the

42:36

peristaltic activity of that bladder.

42:38

The muscle starts forcing urine backwards or to the sides, and it ends up,

42:43

um, looking very abnormal. As we see here, uh,

42:47

in posterior valves. Uh, we know that there's an actual, uh,

42:52

abnormality of the folds of the urethra. And we know, like I was saying,

42:57

that the presentation can be quite variable.

42:59

The cases we see early are the most severe. Typically,

43:02

if we identify it antenatally prenatally,

43:05

we can sometimes try to intervene.

43:07

There have been various treatments directly to the urethra,

43:11

and this is a small structure in the fetus,

43:12

so you can imagine that would be quite challenging and not always successful.

43:16

And sometimes we just try and deal with the secondary effects,

43:19

as I mentioned at the beginning,

43:21

shunting fluid out of the bladder into the amniotic space. And if necessary,

43:26

if there's no amniotic fluid,

43:28

we can infuse a supplemental amniotic fluid. There have even been cases where,

43:32

uh,

43:33

ports have been placed in the maternal abdominal wall with a catheter extending

43:37

into the intrauterine space. And then the patient, the,

43:40

the maternal patient can undergo chronic, um, recurrent, I should say,

43:45

recurrent infusions of amniotic fluid over the course of however much of the

43:50

pregnancy is left. These are very, um, controversial treatments.

43:54

They're not used everywhere and they're not always successful.

43:57

It requires a lot of patient compliance.

43:59

It requires incredible regular visits to the hospital.

44:04

And even then, um, with variable success. So lots of follow-up,

44:08

lots of monitoring in those cases. Here's just an image, um,

44:12

showing the areas of the posterior urethra that tend to be dilated

44:16

proximal to this membranous urethra.

44:18

And that gives us that keyhole appearance that we see. And, um,

44:23

often, uh, in valve cases, we can see them more distally.

44:28

So this is a case you'll notice an abnormal bladder, quite trabecula,

44:31

and then you'll see this outpouching, but that's not the posterior urethra,

44:35

of course, that's much more distally. That's an anterior urethral valve.

44:39

And interestingly,

44:39

anterior urethral valves tend to be caused by a flap of membrane tissue

44:44

in the urethra that leads to a diverticulum. It diverts the flow of urine,

44:49

it creates a, an abnormal jet against the wall of the anterior urethra.

44:53

And over time, that jet creates an outpouching, a diverticulum.

44:56

So anterior urethral valves frequently seen with anterior

45:01

urethral diverticula. And this is just such a case, uh,

45:05

here you can see, uh, it gets quite expanded.

45:08

You might even be tempted to think this is the tip of the urethra at the,

45:12

at the fossa navicular airis, but it's not the,

45:15

the external MEUs is way down here.

45:19

This is the outpouching from the membrane causing abnormal dynamics of

45:23

that fluid jet during voiding. Uh, and here's some cases, uh,

45:29

a pathologic, um,

45:31

photographs and surgical images showing the membrane that was diverting the flow

45:35

of urine. And that has to be, uh, resected. And,

45:38

and you can see significant enlargement of the external genitalia because

45:42

there's significant enlargement of the urethra. So those are rare cases,

45:47

but uh,

45:48

if you just remember that there can be valves anywhere along the urethra,

45:52

most commonly posterior, but also possible anteriorly.

45:56

It's a good thing to keep in your differential when you see those abnormal

45:59

presentations. Um,

46:00

another presentation that can look like a bladder outlet obstruction,

46:05

very similar to urethral valves, is prune belly syndrome.

46:08

It can give us that enlarged bladder, dilated, tortuous ureters, big kidneys.

46:12

Um, but in this case, there is no valve.

46:15

There's some abnormalities of the musculature,

46:17

and it's not just the urinary tract musculature,

46:19

but also the abdominal wall musculature. So here you can see, uh,

46:23

this is AKUB radiograph, an umbilical stump clip right here.

46:27

And you can see how the anterior abdominal wall is not competent and all these

46:32

gas filled loops of bowel are sort of hanging out from what should be a tighter

46:35

intraperitoneal space. There's just a lot of, uh,

46:38

expansion of that space in the anterior abdominal wall is very flacid. Um, and,

46:43

and so, uh, there's also, you know, association with cryptorchidism and, uh,

46:48

this can be very hard to tell apart from posterior valves. Prenatally,

46:52

postnatally, it's not a difficult question at all because the appearance,

46:57

the visual appearance of the abdominal wall on an infant with prune belly is

47:01

quite distinctive. Uh, it's quite memorable. So no one would be confused, uh,

47:06

with an image like this. So remember,

47:09

just because something's in your differential as a radiologist,

47:12

it might not be a differential decision or a dilemma for the pediatrician.

47:17

So it's good to communicate with our colleagues and, um,

47:20

we can know more together than each of us knows in isolation. Uh,

47:25

very rarely we can see urethral strictures. Um, as I mentioned,

47:29

these are uncommon, um, in the prenatal or neonatal period, but,

47:34

uh, they are possible and there are very uncommon congenital urethral atresia.

47:39

All of these, depending on how severe would present with bilateral,

47:43

usually symmetric, uh, renal pelvic obstruction,

47:47

ureteral obstruction, enlarged bladder. Um,

47:50

I'm gonna move past this case of anterior urethral stricture and talk about the

47:54

genital tract.

47:55

I just wanna briefly remind us all of the mulian ducts and the fact that

48:00

there's a fusion of the two mulian ducts.

48:04

And if any point along that process of fusion, there's an interruption,

48:09

then there can be abnormal separation of the two sides of the uterus,

48:13

the two sides of a septated, uh, vagina.

48:16

And there can also be abnormalities at the point of connection between the

48:21

posterior vagina and the anterior vagina because the posterior or deeper

48:26

portion of the vagina is associated with the uterus and develops separately and

48:31

then fuses, um, with the, uh,

48:34

more distal or anterior vagina.

48:36

And that's gonna be associated with the urogenital sinus.

48:41

And so if there's a failure of complete fusion or opening up,

48:45

just like we were talking about with UPJ obstructions,

48:48

you can have abnormalities there. You can have a transverse vaginal septum,

48:51

you can have an imperforate hymen, uh,

48:54

all of which can cause genital tract obstruction.

48:56

So here's an artist illustration of the fusion of the mulian ducts,

49:01

uh, the red on this illustration,

49:03

and they should completely fuse at the uterus and at the vagina.

49:08

And then the walls at their point of fusion should be resorbed completely to

49:12

have the normal configuration. If that gets interrupted,

49:16

we see abnormalities of fusion and we can see various anomalies. The most,

49:21

um, you know, sort of severe end of the spectrum would be a unicorn.

49:25

You at uterus where the, you know, uh,

49:28

rudimentary horn of the other side is completely disconnected or not even

49:32

visualized all the way up to the least severe,

49:35

the arcuate uterus where the only thing that hasn't resorbed is a tiny bit of

49:39

residual myometrium at the fundus. And you might think, well,

49:44

that's not a real problem. And you're right,

49:46

if it were just a little bulge of muscle at the fundus,

49:49

who really cares about that? It's not nearly as big of a problem as having,

49:53

you know,

49:53

like a delphis uterus where you've got two different utero and you know,

49:58

there's a potential for asymmetric pregnancy and things like that. Um,

50:03

the only thing to bear in mind is that with the muscular anomaly,

50:08

with the residual muscular tissue,

50:10

there can also be a thin membrane down the center,

50:12

and the arcuate uterus is highly associated with a septated uterus.

50:17

So we might not be seeing it on these three D ultrasound images,

50:20

four D ultrasound images,

50:22

but if there's a septum there that can lead to abnormal implantation.

50:26

So here's a patient, um, teenage patient having problems with menstruation.

50:30

There's a workup with a pelvic ultrasound, and here's the corollary, MRI,

50:35

and you can see just the tiniest little bulge. Uh,

50:38

here's the myometrium on ultrasound right here, and then these echogenic, uh,

50:43

endometrial spaces. And then here on MRI, it's much clearer, uh,

50:47

that there's just a slight thickening. This is an arcuate uterus.

50:51

Not too much of a problem by itself unless associated with a septum. Uh,

50:56

here's another, uh, image where you can see septation.

50:59

So this arcuate uterus has a very thin, almost imperceptible uterine septum.

51:04

And then down here, as you get closer down by the cervix,

51:08

it's much more obvious.

51:09

That's a big problem because of implantation in the case of pregnancy.

51:14

And I'll show you an example of that in just a minute. Um,

51:17

here's patient number two. This is a transverse ultrasound image.

51:20

And you can see there are two different horns, uh,

51:24

of the uterus.

51:25

This one shows the endometrial space a little bit better than this one. And, um,

51:30

this was a bicornuate uterus.

51:32

Now you can have the cervix be single bicornuate unicos,

51:36

or you can have bicornuate bico.

51:39

That's not the same thing as a delphis,

51:41

it just means that there's such a deep residual division.

51:45

It extends all the way down to the cervix.

51:48

But there is some degree of commonality. You know,

51:51

the very external os of the cervix would be singleton,

51:54

even though the deeper cervix that internal os would, you know,

51:59

be duplicated. So this is the bicornuate.

52:01

The way to tell the difference between this and the arcuate is you need to see

52:04

the outside of the uterus.

52:06

If there's this cleft on the external aspect, it's bicornuate.

52:11

If we saw this appearance, but the fundus was normal,

52:14

we would call this a very dramatic arcuate uterus.

52:17

And here's another case where you can see a uterine fundus here on ultrasound

52:22

uterine fundus here on ultrasound with the big extrinsic cleft between them.

52:27

Uh, another image, 17 year old, two different fund I. And, uh,

52:32

one of them is a little bit dilated. We're thinking,

52:35

could that be a gestational sac? Could they have an asymmetric pregnancy?

52:39

And in point of fact, that patient did have an asymmetric pregnancy.

52:42

Here's another patient, separate patient, uh,

52:44

where you can see cross-sectional imaging demonstrating the delphis,

52:49

the twin, uh, uterine, which,

52:51

which this is just a more severe degree of failure of fusion. Here's, um,

52:56

a septation which can be associated with any of these malaria and duct

52:59

anomalies. And that septation has, uh, obstruction somewhere distally.

53:04

You can see all the fluid filling, uh, the endometrial space.

53:08

Here's a serial Mr imaging of a patient with two

53:13

fundi. But as you come more distally towards the cervix, one of those fund, uh,

53:18

fundus disappears. And when you get down to the cervix,

53:21

you only have the one structure. This is a unicorn at uterus,

53:25

which this side extends down to the fund, uh, to the cervix.

53:29

With a rudimentary horn that's completely obstructed.

53:32

It has endometrial tissue.

53:34

It is going to attempt to slough off that endometrial tissue with hormone

53:38

shifts. So menstruation might be attempted, but if there's no outlet,

53:41

you can develop increased pressure.

53:43

Here's some blood fluid levels and that needs to be resected eventually.

53:47

There are even rare reports of these, um,

53:49

leading to a pregnancy in the rudimentary horn. Um,

53:52

there are several mechanisms proposed. Very rare, unlikely,

53:56

but it has been reported. So here's all the Malian anomalies and uh,

54:01

I just wanna return to this question of a septated uterus.

54:04

And it's why we care even about arcuate. We look very carefully for a septum,

54:08

because the septum doesn't have myometrial tissue and myometrial tissue.

54:13

The inner myometrium is necessary to develop all of those spiral arteries to

54:18

create the,

54:18

the proliferation that is the precursor to the placenta.

54:23

So you need this decidual reaction to develop a placenta.

54:26

If the zygote or, you know, uh,

54:30

blast assist or whatever stage it's at,

54:32

implants into the endometrium on this septum, but there's nothing behind it.

54:37

It's not going to be able to develop the vasculature necessary to sustain a

54:42

pregnancy. So there are patients who present with recurrent uh,

54:46

miscarriage and, um,

54:49

the cause can be a septated uterus and they're just having multiple pregnancies

54:54

implant on that septum.

54:55

So if you see any form of malaria induc anomaly look very carefully for a

55:00

septum. The septum can be up high only,

55:02

or it can extend all the way down into the vagina. Uh,

55:05

and it's a little easier to detect in those cases. Um, and lastly,

55:10

in our final few minutes,

55:11

I just wanna talk for a moment about a urogenital sinus.

55:16

The most severe form of failure of separation of all the different tracts at

55:20

the pelvis and perineum is AC cloaca.

55:23

And I have an image here of a chicken because in the normal anatomy of the

55:26

chicken, there is only AC cloaca.

55:29

The eggs emerge from the same vent where the fecal matter and the urine emerge.

55:34

It all comes from the same place. And if you've ever owned chickens,

55:36

you've collected some eggs that have a little bit of, uh, dirt on them,

55:41

we'll say, but they're not completely clean.

55:43

You have to wash those eggs in the human. Of course,

55:45

there should not be a cloaca,

55:47

that's an embr logic point that's only transient.

55:51

And then we should first have separation of the GI tract from the urogenital

55:55

tract, and then later separation of the urine from the genital tract.

55:59

If that gets interrupted, you can have a cloaca that's a,

56:02

a more severe abnormality. Or um,

56:05

even more commonly you can have a urogenital sinus where you have a normal

56:09

sphincter for your anus and rectum,

56:11

but only a single common channel at the perineum for urine

56:16

and genital tract. And, uh, that's going to need to be repaired by urology.

56:21

So urogenital sinus is an abnormality that we can identify.

56:25

This is an adult patient who had a fluoroscopic study where contrast was

56:29

injected into the, uh, cloaca. And you can see all three tracts.

56:33

Typically in children.

56:34

We'll do A-V-C-U-G if there's a suspected urogenital sinus,

56:37

and sometimes it can be quite easy to catheterize through that common channel

56:43

into the wrong track.

56:44

So here's a case that I performed where I thought I had catheterized the

56:47

bladder. It can be quite difficult to identify.

56:50

You inject a little bit of contrast and you'll note right away that this

56:54

structure on top of what I thought was the bladder leads us to quickly realize

56:58

we're not in the right place. And in fact,

57:01

we're in the genital portion of this common urogenital tract. And uh,

57:05

when I turned the patient sagittal,

57:07

you can see a very clear outline of the cervix.

57:11

So this is contrast that has gone into the vagina.

57:13

You can see it in the fores of the posterior vagina and a tiny little string

57:18

going through the cervix up towards the uterus.

57:20

So we pulled the catheter back and we redirected. And um,

57:25

here now you can see we've gone anteriorly into the bladder because

57:30

there's a common channel when the patient voided contrast refluxed even more

57:35

back into the uterus and vagina. So you can see a quite dilated vagina here,

57:39

and then an plexed uterus that overlaps with the bladder.

57:43

So this is a case of urogenital sinus,

57:45

and you'll notice that there is a short common channel,

57:50

and that's a good thing for the patient.

57:51

The short common channel gives much more latitude for the urologist to separate

57:56

the urethra and reimplant that if there's a long common channel,

58:00

there's not much channel that's individual to each tract,

58:05

and that's very hard to repair. So when you're doing these studies,

58:08

you're often asked to evaluate the length of the common channel,

58:11

short common channel equaling better prognosis,

58:15

and here's all those images altogether. So just reaffirming what I said,

58:19

short common channel is best.