0:01

So our last section that we're gonna cover in our head

0:04

to toe or north, north to south imaging

0:06

of newborns in the NICU is genital urinary imaging.

0:10

And a lot of this we're gonna be focused on the kidneys.

0:13

So let's talk about congenital hydronephrosis

0:17

or neonatal hydronephrosis.

0:18

So in this part of this review,

0:20

we're gonna talk about why this is important.

0:23

We're gonna talk about the consensus nomenclature.

0:25

Currently we're gonna know when

0:27

to call a kidney normal in the setting

0:29

of congenital hydronephrosis,

0:31

and then we'll learn how to appropriately grade, um,

0:34

urinary tract dilatation postnatally.

0:37

So, uh, prenatal urinary tract dilatation is a big deal

0:41

because it's pretty common, uh, finding

0:43

that is found on prenatal imaging in up

0:46

to 2% of all pregnancies.

0:48

So this leads to a lot of imaging costs, not

0:51

to mention parental anxiety, um, of a mom who has a baby

0:56

who might have a congenital anomaly of the kidney

0:59

and urinary tract.

1:00

These are expensive because of prenatal

1:02

and postnatal imaging, not to mention patients who have

1:05

to go on to voiding, cysto urethrogram, uh,

1:08

or contrast enhance voiding cystogram plus slash minus

1:11

antibiotic therapy.

1:13

So the goal of imaging the kidneys in patients

1:16

with suspected congenital, um, hydronephrosis is

1:19

to identify complications

1:21

or anomalies rather prior to complications such

1:24

as urinary tract infection or stone formation.

1:28

The good news is most cases

1:30

of in utero congenital hydronephrosis resolve spontaneously.

1:35

And so we'll get a follow-up postnatal renal ultrasound

1:39

and the hydronephrosis will spontaneously resolve.

1:43

So a group of multidisciplinary urologic imagers urologists,

1:48

um, fetal imagers came together

1:50

to create some consensus guidelines for how to appropriately

1:55

classify and care for infants

1:56

with congenital hydro necrosis.

1:59

Um, so there are both antenatal presentation

2:01

and postnatal presentations of urinary tract dilatation, um,

2:06

where we will appropriately classify patients into low risk

2:09

versus high risk.

2:11

And the higher the number, the greater the likelihood

2:14

that there will be an abnormality

2:16

that will require surgical intervention.

2:20

Um, so management is based on the severity.

2:24

So ANTENATALLY is the UTDA system where one is low risk

2:28

and two slash three is moderate to intermediate

2:32

or moderate to high risk.

2:33

Rather, these patients will get two ultrasounds postnatally,

2:37

one after 40 hours of life to one month of life,

2:40

and then a second, six months later

2:43

if there's bilateral hydronephrosis follow up is based on

2:46

the more severe side.

2:48

Importantly, the recommendations are to do ultrasound

2:52

after 48 hours of life,

2:53

to not underestimate the degree of dilation.

2:57

Infants have physiologic

2:59

Oliguria, um, prior to 48 hours of life.

3:01

So we wanna wait to make sure

3:02

that we're not underestimating the severity

3:04

of hydro necrosis.

3:07

Um, I also wanna say that in patients who have, uh,

3:10

severe antenatal abnormalities, seen sonographic, um,

3:14

you don't wait four, eight hours to image those patients.

3:16

Those patients go straight to, uh,

3:18

renal ultrasound immediately following birth.

3:22

And then you don't wanna wait too long

3:23

before you image patients postnatally

3:25

because if there's a severe abnormality,

3:27

you wanna diagnose it sooner rather than later.

3:30

In this consensus guidelines, the recommendation is to image

3:33

and prone 'cause you want the degree of hydronephrosis to be

3:37

as severe as possible.

3:39

So in infants, typically the renal pelvis is located as sort

3:43

of oriented more anterior to posterior.

3:46

And in the prone position,

3:47

a collecting system will open up a little bit

3:49

and look more severe in prone compared to supine.

3:52

So you wanna grade the hydronephrosis, uh, when it's

3:56

as severe as possible,

3:57

which is in the prone position typically.