Pediatric Voiding Dysfunction

Question 1

What tests would you order on a 6 yo with spina bifida (s/p back closure as baby, L5 myelomeningocele) who presents with worsening urinary incontinence, urgency, and recurrent UTI?

Answer 1

RBUS
VCUG
UDS
MRI spine

Question 2

What would be your main dx for 6 yo with spina bifida (s/p back closure as baby, L5 myelomeningocele) who presents with worsening urinary incontinence, urgency, and recurrent UTI?

UDS shows small capacity bladder with intact sensation, poor compliance, uninhibited contractions, high DLPP, VUR

Answer 2

Tethered cord (MRI)

Question 3

What is normal bladder capacity for a child?

Answer 3

Normal bladder capacity = (age +2) x 30 mL

Question 4

What is DLPP and what is the upper threshold?

Answer 4

Detrusor leak point pressure – leakage in absence of valsalva or contraction

The detrusor leak point pressure (DLPP) is a measure of the pressure at which the detrusor muscle in the bladder begins to leak urine during the filling phase of the bladder.

The DLPP is measured during urodynamic testing, a diagnostic test used to evaluate bladder function. During the test, a catheter is inserted into the bladder and the bladder is filled with fluid. The pressure in the bladder is measured at various points, including when the detrusor muscle begins to leak urine. The DLPP is the pressure at which this leakage occurs.

sign of poor compliance

>40 cm H20 causes renal damage

Question 5

Initial treatment for child with detrusor hyperreflexia, poor compliance, VUR, DLPP > 40 cm H20? Without tethered cord.

Answer 5

CIC + AC drug
CaP for VUR
Bowel regimen
Regular f/up UA, UCx, Renal US, Cr

Question 6

What would be next steps for progression of bladder hostility, pyelonephritis, worsening hydro, or renal function loss?

Answer 6

Augmentation (+ reimplant if VUR)
Mitrofanoff, considered in boys
MACE

Question 7

In a boy with spina bifida and UI (L4 myelomeningocele), what is initial workup of worsening or uncontrolled leakage?

Answer 7

RBUS
VCUG
UDS
+/- MRI

Question 8

In a boy with spina bifida and UI (L4 myelomeningocele), RBUS demonstrates L hydro with loss of parenchyma, VCUG demonstrates Grade IV/V L VUR, bladder neck open, what testing would be indicated to assess kidneys?

Answer 8

DMSA

Question 9

In a boy with spina bifida and UI (L4 myelomeningocele), RBUS demonstrates L hydro with loss of parenchyma, VCUG demonstrates Grade IV/V L VUR, bladder neck open, DMSA demonstrates 65%/35%, L/R.

UDS shows:

small capacity, overactive bladder (DO 30 cm H20, SUI, elevated PVR)

First tx options? If failed first options?

Answer 9

First options: CIC + AC, CaP for VUR

Failed non-invasive:

1. Autoaugmentation with ureteral reimplant and bladder neck sling
2. Augmentation enterocystoplasty (stomach, ileum, colon) with transvesical ureteral reimplant and sling (autologous or cadaveric vs. AUS)
3. Continent vesicostomy (Mitrofanoff with bladder neck closure) + MACE

Question 10

Complications and management of bladder augmentation:

Answer 10

1. Autoaugmentation (detrusor myotomy):
   
   1. Damage to urothelium → repair 4-0 chromic
   2. Persistent bladder leak → continued urethral catheter
2. Augmentation enterocystoplasty
   
   1. Contraction with incontinence → AC
   2. Mucus → flush
   3. Hematuria/dysuria syndrome → stomach only, H2 blocker, HCO3
   4. Stones → irrigation, extraction
   5. Spontaneous perforation → peritonitis and death (5-10%), first cath drainage, operate based on clinical suspicion (cystogram can be FN)
   6. Metabolic acidosis → stomach/colon, can lead to osteoporosis → tx oral NaHCO3 or Na/K Citrate
   7. Metabolic alkalosis → stomach, H2 blocker
   8. Malignancy → adenocarcinoma of bowel, or UC bladder, if new blood in urine or recurrent UTI do cysto, B12 deficiency (terminal ileum), pernicious anemia/neuropathy

Question 11

In patient with lethargy, fever, and VP shunt, what should be done?

Answer 11

Consult NSG to r/o shunt failure

Question 12

Describe open cystolithotomy on augmented bladder:

Answer 12

1. prep and drape
2. place foley
3. lower midline incision
4. place ring retractor
5. incise detrusor
6. avoid bowel portion of bladder
7. remove stones
8. close incision in layers
9. leave SPT, Foley, drain

Increase interval of CIC and consider irrigation regimen

Question 13

What are treatment options for 21 yo M with hx of L1 myelomeningocele with UDS demonstrating normal capacity and compliance, SUI but not UUI?

Answer 13

1. Periurethral bulking (success low)
2. Male sling (may need to CIC after)
3. Leadbetter trigonal tubularization
4. Tanagho bladder neck tubularization
5. Kropp anterior bladder tube implantation
6. AUS (revision 5-7 y)

Question 14

Describe AUS:

Answer 14

1. Dorsal lithotomy
2. Inguinal incision for pressure reservoir (61-70 H2O used for bulbar urethra)
3. Perineal incision for cuff placement → measure urethral circumference (4.5 cm common in bulbar urethra)
4. Connect tubing
5. Cycle the sphincter
6. Lock the cuff in open position
7. Leave foley overnight
8. Activate at 6 weeks

Question 15

If a patient has an AUS and develops hydronephrosis, worsening renal function, what is first step? What diagnostic testing is necesary?

Answer 15

First step it to ensure sphincter is working and deactivate it with cuff in open state, catheter to check PVR

US (done as mentioned in stem) VCUG ( to assess for VUR)

Need UDS

Question 16

What is ddx of 15 yo M with enuresis and neurologic findings (decreased DTR, decreased rectal tone), not previously dx with any congenital issues? What tests should be ordered?

Answer 16

tethered cord
spinal dysraphism

Order: RBUS, KUB, VCUG, UDS, MRI spine

Question 17

What are treatment options for 15 yo M with tethered cord and small capacity, overactive bladder with high DLPP and no SUI?

Answer 17

1. Anticholinergics
2. Timed voiding
3. Bowel regimen
4. CIC
5. NSG for cord de-tethering

Question 18

What surveillance is utilized for spina bifida patient with or without surgical intervention?

Answer 18

Yearly RBUS, Cr (cystatin C)

changes in sxs: UDS

UTIs/blood: cysto

Question 19

If medication and cord de-tethering do not work for a poorly compliant, small bladder patient with incontinence, what are next steps?

Answer 19

Bladder autoaugmentation or enterocystoplasty

may need CIC

consider continent catheterizable channel

Question 20

First goal of pediatric NGB management in babies with spinal dysraphism? What tests are done?

Answer 20

protect the kidneys from high bladder pressures and incomplete emptying
ID newborns at risk of renal damage

GET RBUS in first few days of life
* can consider contrast enhanced US

Look for:
hydronephrosis, parenchymal anomalies, bladder appearance

Consider VCUG (once patients can lie on back, once defect closed)

Question 21

What workup should a baby with spinal dysraphism have in the early months after discharge from the hospital?

Answer 21

Urodynamics and a repeat renal bladder ultrasound are typically obtained around 2-4 months of age.

It is important to highlight that there are no reference values for bladder dynamics this early in life.

Several urodynamic findings have been associated with risk of UTI and kidney scarring including bladder trabeculations, VUR, high storage pressures evidenced by end fill pressure or detrusor leak point pressure > 40 cm H2O, and detrusor sphincter dyssynergia.

Question 22

Initial CIC determination in infants is utilized until first UDS based on which factors?

Answer 22

consistently high bladder pressures or high residuals
trabeculated bladder
high grade VUR
high grade hydronephrosis

Question 23

A 2-4 month old with urodynamics that is LOW risk for upper tract damage will have these features

Answer 23

A patient who is very low risk for upper tract damage on urodynamics will have

• a smooth walled bladder without VUR
• low bladder residuals
• low leak point pressures

Question 24

For a baby’s first urodynamics, urodynamic findings have been associated with risk of UTI and kidney scarring include:

Answer 24

Bladder trabeculations

VUR

High storage pressures evidenced by end fill pressure or detrusor leak point pressure > 40 cm H2O

Detrusor sphincter dyssynergia

Question 25

How do you decide if you should initiate CIC in a 2-4 month old?

Answer 25

If on urodynamics at 3 months, there is high end fill or detrusor leak point pressures (> 40 cm H2O), evidence of detrusor sphincter dyssynergia, or grade 5 VUR

in addition to q4h CIC, protocol can start patients on Oxybutynin 0.2 mg/kg TID

Question 26

Spina bifida follow up in the first year of life

Answer 26

clinic visit with assessment for any interim UTIs and renal bladder ultrasound every 3-4 months,

with urodynamics often repeated around 1 year of age or sooner if clinically needed

After the 1^st year of life, follow up visits are typically spaced out to every 6-12 months. The need for routine urodynamics after the 1^st year of life is unclear. Some centers recommend a baseline DMSA scan to establish the presence of renal scars as these scars correlate well with development of hypertension. However, in patients with normal ultrasounds who do not have a history of UTIs, VUR, or trabeculated bladder the utility of routine DMSA scan is of questionable utility as these patients are unlikely to have any DMSA abnormalities.

Question 27

What do you do for a “high risk” bladder in infancy and childhood?

Answer 27

Approximately 30% of children with spina bifida will have a high risk bladder.

A patient with a trabeculated bladder with VUR and high storage pressures has a very high risk of developing UTIs and renal damage.

Starting CIC and anticholinergics in these patients may prevent UTIs and renal damage.

The anticholinergic most commonly used is oxybutynin, 5mg/5mL elixir 0.2 mg/kg BID-QID.

All anticholinergics are off-label in neonates and children.

Early initiation of medical treatment has shown lower rates of renal function deterioration and need for bladder augmentation.

Side effects may limit dose adjustments. This can be reduced with intravesical use of anticholinergics. Intravesical oxybutynin can be dosed as 0.1 – 0.8 mg/kg TID. More recent literature supports the use of β3 agonists and has shown improvement in urodynamic parameters.

Overnight Foley catheter drainage can also be started to avoid high storage pressures by keeping the bladder empty all night as well as to help prevent UTIs.

Question 28

When do you consider vesicostomy?

Answer 28

In infants or young children with neurogenic bladder who have persistent UTIs or concern for upper tract deterioration, despite regular CIC, anticholinergics, and overnight catheter drainage, early and strong consideration for vesicostomy should be given.

A vesicostomy is very successful in protecting the kidneys from the bladder and CIC and anticholinergics can generally be stopped. Risks of vesicostomy include bladder prolapse and stomal stenosis. Eventually, the vesicostomy is typically taken down and a bladder augmentation with other reconstructive surgeries can be done at the same time as vesicostomy take down.

We typically recommend waiting until at least age 5 before considering taking down the vesicostomy and obtaining a urodynamic study prior to this to evaluate for persistent of VUR, bladder size, and bladder compliance.

Management of VUR with ureteral reimplantation has not shown any benefit and should rarely be considered. Because these patients typically have high outlet resistance, a bladder outlet procedure is generally not needed at time of vesicostomy take down and augmentation cystoplasty with resulting high continence rates.

Question 29

What are major risk factors for spinal dysraphism (spina bifida)

Answer 29

extreme maternal age
family history
maternal diagestes
obesity
use of perinatal valproic acid or carbamazepine
folic acid deficiency

Question 30

What are the goals of pediatric neurogenic bladder management

Answer 30

1. Protect the kidneys and prevent their deterioration resulting from high bladder pressures.
2. Achieve continence.
3. Achieve independence.
4. Avoid reconstructive surgery if possible.
5. Avoid or reduce frequency of symptomatic urinary tract infections.

Question 31

What does anemia from renal insufficiency look like? Why does it happen?

Answer 31

microcytic
MCV value low/normal
reticulocyte low

low erythropoietin

Question 32

4 categories of reconstructive surgery in patients with spina bifida

Answer 32

1. Protect the kidneys and prevent their deterioration resulting from high bladder pressures.
2. Achieve continence.
3. Achieve independence.
4. Avoid reconstructive surgery if possible.
5. Avoid or reduce frequency of symptomatic urinary tract infections.

Question 33

What is an appropriate dosing of botox for patient with spina bifida and NGB?

Answer 33

200-300 IU