0:00

So these are the things we're gonna look

0:02

for when we're talking about

0:03

classifying urinary tract dilatation.

0:05

That's the anterior to posterior renal pelvis diameter,

0:08

the location of CAE dilatation, if any,

0:11

and then any renal parenchymal thickness abnormalities

0:14

or appearance abnormalities, any ureteral abnormalities,

0:17

and then any urinary bladder abnormalities.

0:20

So the anterior posterior renal pelvis diameter,

0:23

the AP renal pelvis diameter,

0:25

you measure the greatest anterior to posterior dimension

0:28

of the renal pelvis, not an extra renal pelvis.

0:32

So you have to be measuring within the renal parenchyma.

0:34

So this article nicely shows these green arrow locations are

0:38

acceptable locations

0:39

to measure your AP renal pelvis diameter,

0:42

not the gray arrow.

0:43

The extra renal pelvis can be as large as it wants

0:46

to be in the system when we're talking about ectasis

0:50

instead of the anatomic names, major and minor caly.

0:54

They didn't want there to be any confusion about

0:57

somebody saying major lye dilation

0:59

and confuse it for like major hydronephrosis.

1:02

So they call the caly central versus peripheral caly.

1:06

So the central lyes are just closer

1:08

to the renal pelvis location.

1:10

And the peripheral lyes are the anatomically the minor lyes

1:14

or the cups of the tips of the medullary pyramids.

1:18

Um, ureteral dilation is just, you're allowed

1:21

to see transient, uh, visualization of the ureter,

1:25

but you're not supposed to see consistent dilation

1:28

or a marked dilation of the ureter.

1:30

So if you see, um, consistent

1:32

or marked dilation of the ureter,

1:34

that is a ureteral abnormality.

1:35

That's ureteral dilation in the system.

1:39

And then the urinary bladder,

1:40

when you're talking about abnormalities

1:41

of the urinary bladder wall, the funny thing to me is

1:44

that a ureter seal in this classification system is

1:47

considered a urinary bladder abnormality,

1:50

not a ureteral abnormality.

1:52

So, um, reil counts as a urinary bladder abnormality,

1:57

a thick walled urinary bladder

1:58

or a dilated posterior urethra, especially in a male.

2:02

Those are considered, um, urinary bladder abnormalities

2:06

and the grading will be UTDP three,

2:09

the highest of the grades.

2:11

Renal parenchymal abnormalities might be, uh, too bright.

2:14

Renal parenchyma. Uh, when you're comparing to, uh,

2:17

adjacent organs, uh, you might have loss

2:20

of cortico differentiation or renal parenchymal cyst

2:23

and then you could have thinned renal parenchyma

2:25

as an abnormality of the renal parenchyma.

2:28

So any of those parenchymal abnormalities, um,

2:31

or abnormal urinary bladder automatically will classify you

2:35

as UT DP three.

2:38

If you only have peripheral calo cell dilatation

2:40

or abnormal, uh, ureter, um, that is UTP two.

2:44

And then the low risk category is if you have an EP renal

2:47

pelvis diameter, um, which is just a little bit big

2:51

or you have central cace dilation, a reminder

2:54

that you grade based on the most severe

2:57

finding that is present.

2:58

So if you, you have an abnormal bladder,

3:00

but you only have a little bit of CIL dilation,

3:03

that still counts as UT DP three.

3:06

So you grade it, you assign the classification based on the

3:09

most severe finding that is present.

3:13

A reminder that we don't use the urinary tract dilatation

3:15

grading system for obvious abnormalities.

3:18

So if you have a solitary kidney, an ectopic kidney,

3:21

a multicystic dysplastic kidney, or other cystic dysplasias,

3:25

and you don't use the UTD uh, classification system

3:28

for any postoperative patients.

3:29

So this is an example of an autosomal

3:31

recessive polycystic kidney.

3:33

We would not assign, uh,

3:35

a UTD grading system for this patient.

3:38

So let's look at some examples.

3:39

This is a two day old infant with prenatal ectasis

3:43

and we have postnatal ectasis as well,

3:46

but our AP renal pelvis diameter is only four millimeters.

3:49

We don't see renal klyce,

3:50

so this is my favorite of the options.

3:52

This is totally normal.

3:54

We can just say normal kidney, no urinary tract dilatation.

3:58

We don't have to say physiologic ectasis or anything.

4:01

This patient can move on.

4:03

Now, importantly, um, in a patient

4:05

who has ectasis without ectasis

4:08

or any other abnormality,

4:09

these patients will still get one more followup ultrasound

4:13

at one to six months

4:14

of life per the UTD classification system.

4:17

Um, recommendations.

4:20

Let's move on to the next risk category

4:21

and that's U TDP one.

4:23

These are still low risk patients.

4:25

Um, you will have findings of either central ectasis

4:28

or an AP renal pelvis diameter of 10 to 15 millimeters.

4:32

So here is an example of an almost one month old infant

4:35

who had a diagnosis of prenatal, uh, hydro necrosis.

4:38

Although our AP renal pelvis diameter is only three

4:41

millimeters, this patient has some central CLI ectasis

4:44

of this upper pole kidney.

4:46

So even though the AP renal pelvis diameter wasn't very big,

4:49

the fact that we have central ectasis makes this a ut DP one

4:54

urinary tract dilatation.

4:55

Because of that central ectasis,

4:58

these patients are managed similarly to normal patients

5:01

where they'll get a follow-up ultrasound

5:03

at one to six months of age.

5:04

Any sort of other additional imaging like voiding, cysto,

5:07

urethrogram, uh, prophylactic antibiotics, um, are up

5:11

to the discretion of the clinician if

5:13

they're concerned or not.

5:14

And then functional imaging like nuclear scintigraphy is not

5:17

recommended in these patients.

5:20

For UTD P two, that's the intermediate risk group.

5:23

Um, for, to make that diagnosis.

5:24

The AP renal pelvis diameter has

5:26

to be at least 15 millimeters in diameter,

5:29

or you have to have an abnormal ureter

5:31

or peripheral ectasis.

5:34

So this is a four day old infant

5:35

who had prenatal hydro necrosis.

5:37

The AP renal pelvis diameter was only three millimeters,

5:40

but we have not only central uh, ectasis,

5:43

we can see our peripheral caly.

5:46

So, um, my favorite description of the peripheral caly

5:49

or the, uh, minor caly is that it should be

5:52

so pointy you can pick your teeth on it like a toothpick.

5:54

And so if it's blunted like this, if

5:56

It looks not like a toothpick, that's peripheral ectasis.

6:00

And so that classifies as

6:02

UTDP two in the UTD classification system.

6:07

Um, this is similar recommendations

6:09

for follow-up and management.

6:10

Uh, after imaging, again, they get a follow-up ultrasound,

6:13

VCU gene Prophylactic antibiotics are at the discretion

6:17

of the clinician based on, uh, their level

6:19

of concern of the patient.

6:21

Here is an example of an infant

6:23

who had UTD high risk antenatal ultrasound.

6:26

We only have a five millimeter AP pelvis diameter,

6:29

but we have this abnormal, um, visualized upper ureter.

6:34

So, uh, measuring up to three millimeters in diameter.

6:37

So this, because of the presence

6:38

of the ureter ectasis is UT DP two, regardless the amount of

6:43

ectasis or ectasis, um, at the level of the kidney.

6:48

So in summary, um,

6:49

the UTD classification system is a multidisciplinary

6:53

consensus classification system

6:55

to standardize terminology and grading.

6:57

You wanna wait until 48 hours of life

6:59

to do the postnatal follow-up in a patient

7:02

who has prenatal concern for, uh, congenital hydro necrosis,

7:06

you grade it, um, based on the most severe appearance

7:09

of the hydronephrosis,

7:11

which is typically in the prone position.

7:13

And then you grade it based on the presence

7:15

of the most severe, um, abnormal finding on your ultrasound.

7:20

Let's review some cases now.