1. Jian Guo Wen Nothing to disclose X
† All financial ties (over the last two years) that you may have with any business organization with respect to the subjects mentioned during your presentation X

2. ICS TEACHING MODULE Urodynamics in children Part 1
ICS TEACHING MODULE Urodynamics in children Part 1. CYSTOMETRY IN CHILDREN
Jian G Wen MD,Ph.D, Jens C Djurhuus, Dr. Med.Sci,
Peter F.W.M Rosier MD, PhD, Stuart Bauer, MD
1. Pediatric UD Center, First Affiliated Hosptial of Zhengzhou University, China
2. Department of Clinical Medicine, Aarhus University, Denmark
3 Department of Urology, University Medical Centre Utrecht, The Netherlands
4. Department of Urology, Boston Children’s Hospital, USA

3. Cystometry: outline Background Indications Technique Interpretation
Recommendations
Uroflow
Pdet
EMG
Pabd
Pves
Cystometry,
Pressure/flow study
Conclusions

4. Background
Lower urinary tract dysfunction in children is encountered frequently (20-30%) in clinical practice. Some need to be evaluated by urodynamic studies following a careful history & physical examination
The aim of urodynamic testing is to reproduce symptoms, to identify the underlying causes for symptoms, and to quantify underlying pathophysiological processes
This section follows the guideline from ICS & ICCS on Good Urodynamic Practice
Oracle – “Pee”
B. C.
Urodynamic is spelled wrong

5. Cystometry
When undertaken, cystometry is the core evaluation of pediatric urodynamic study (PUDS) in the evaluation of LUTD/LUTS
It measures the pressure-volume relationship of the bladder during the filling
In this module, its techniques and recording parameters will be introduced in details
Pressure flow study & video-urodynamic studies will not be covered in this section

6. Cystometry in Children
• Indicated from birth and onwards primarily • to monitor compliance and thereby avoid potential damage to kidney function

7. Cystometry: setting Cystometry in children Water pump Flowmeter
Intravesical instillation
6F double lumen catheter
Pabd
Pves
Vinfus
Pressure 
sensor
 Water pump
Bladder pressure and abdominal pressure simultaneously
Cystometry in children
Pves
Flowmeter

8. Conventional Cystometry
1: 6-F transurethral double lumen catheter To monitor vesical pressure and for filling 2: 8-F (optionally balloon) catheter in rectum To register abdominal pressure 3: Levelling the transducers both to pubic level Filling rate usually 5-10% of expected bladder capacity 4: Electronic subtraction of abdominal pressure from vesical pressure = detrusor pressure

9. Indications
Suspicion of, or overt neuropathic voiding dysfunction, LUT obstruction, DSD. etc
Profound non-neuropathic detrusor- sphincter dysfunction (ie.,dilating ureter(s), high grade vesicoureteral reflux, valve bladder syndrome)
Significant PVR with no apparent reason
Congenital malformations of the lower urinary tract (ie., exstrophy, epispadias, ureteroceles, mutiple bladder diverticula)

10. Indications and preparation
5. The procedure is assumed to effect treatment strategies & for evaluating the treatment response or follow up
6. It is undertaken after history taking, physical examination, voiding diaries & uroflow patch EMG recordings. If these measures do not answer the questions related to causes, nor provide management schemes for LUTD
Preparation
Empty the rectum. Enema Glycerini is recommended. Severe constipation may need cleaning enema
Drink sufficient quantities of water in order to have a full bladder for an initial uroflowmetry
Cleaning enema

11. Technique: insert catheters
Double-lumen catheter for Pves, or triple lumen catheter for Pves & Pura recording (3rd channel for filling); rectal balloon catheter for Pabd recording 、
容量 ml
l l l l l l l
EMG
Pura
Pves
Pdet
Pabd
Qura
Filling phase
Voiding phase CP
End
Volume

12. Technique: place surface electrodes
Surface electrodes are positioned symmetrically left & right from the external anal sphincter, to record the reactivity of pelvic floor muscles

13. Technique: position and zeroing the pressure
Upright or supine position – babies may be held in mother’s arm. Before filling the bladder, the vesical pressure channel must be zeroed to the atmosphere with the transducer placed at the level of the pubis
A Credé maneuver or encouraging the child to cough to test the catheter & sensor function

14. Cooperation: during filling
To build the lab so it looks like a kindergarten, and e.g.animation wall with TV
Employ dedicated & knowledgeable staff able to give children an explanation of the procedure and aim of the urodynamic study. If possible, engage the infants to cooperate
Have a well cleansed rectum
After inserting the catheter in the bladder, if the child is still agitated, engage parents to help to keep him/her calm
Animation wall
To avoid cry
Start until calm

15. Cooperation: during filling
The urodynamic evaluation approach should start with as minimally tests as possible, ending up with the invasive investigations, if needed
Toys, eating or drinking, reading, allow mother to be present, during the examination
Apply 1% lidocaine jelly or other topical anesthetic solution instilled into the urethra to aid in catheter passage
Administer sedative if necessary but not an anesthetic, & document if child is very fearful
toys
Drinking
Mother with child

16. Interpretation: filling pressure
Pdet increases initially (< 5 cm H2O) immediately at the start of filling, & incrementally with further filling of the bladder, it reaches a maximum just before the urge to void (normally, < 15 cmH2O).
Detrusor pressure (Pdet)
Bladder pressure (Pves)
Abdominal pressure (Pabd)
Start filling
Flow (Qure)
cough
Filling phase
Voiding
phase

17. Interpretation: detrusor overactivity
Detrusor overactivity indicates a detrusor contraction that occurs during the filling phase before expected bladder capacity is reached &, which may occur in 10% of normal children. While in children with VUR, it may be seen in more than half of the infants 
Detrusor overactivity
Pdet.void.max
Filling phase

18. Interpretation: detrusor compliance (△C)
△C = △V/△ Pdet – measures the visco-elastic properties of the bladder △C < 10 ml/cmH2O indicates decreased bladder compliance, which may due to decreased bladder capacity or increased Pdet or both
Normally, the end filling pressure < 15 cmH2O with a slow filling rate △V
Filling phase
Voiding phase
△Pdet A B
A: The non-linear portions - the beginning & end of the V/Pdet diagram do not contribute to compliance. B: △V / △ Pdet essentially captures the angle of the line describing the incremental increase in resting pressure

19. Bladder capacity (BC), post-void residual (PVR),
Interpretation: estimated bladder capacity based on age
Bladder capacity (BC), post-void residual (PVR),
maximum detrusor pressure during voiding（Pmax.det.void）in the literatures
Age
BC (ml)
PVR (ml)
Pmax.det.void
(cmH2o)
Neonatal
Premature infant（0.5～7w）
13.2±4.9
1.5±1.0 -
（<4w）
22.6±7.8
Term infant （1w）
24.6±10.9
1.4±1.1
（2w）
23.6±8.7
1.2±1.0
Infant
3 month
53±13
5.7±4.5
50～75
12 month
70±30
7.1±6.3
41～66
24 month
79±31
6.6±7.0
38～60
36 month
128±72
3.3±5.3
38～55
Expected capacity (ml) = 30 + (age in years × 30) in a child > 1 year of age;
Expected capacity (ml) = × age (months) for infants < 1 year old

20. Interpretation: bladder capacity, compliance
The mean (SD) for
a, post-void residual urine volume
b, bladder capacity
c, maximum voiding pressure
d, detrusor pressure on voiding
e, bladder compliance in males (green) & females (red) in children of varying age groups
From Wen, et al. British Journal of Urology ,

21. Interpretation: estimate sensation of filling
Evaluating sensation of filling depends on both verbal or non- verbal signs, such as movement of the feet, awakening from sleep, a sudden cry. Bladder filling should be stopped when the filling pressure exceeds 40 cm H2O
In older children, ask them to hold & not void at their first sensation to void, especially if expected or known maximum bladder capacity has not been reached
For newborn & infants < 1year, it is difficult to identify the sensation of bladder filling; however, it is easy to generate urination during the cystometry in these children
Verbal communication

22. Conclusions
Cystometry with an initial ‘free’ uroflowmetry is a useful tool to evaluate the LUT function in children
It should be considered as one procedure, but not the only one, to clarify the diagnosis & to make therapeutic decisions as well as for follow up
To understand the findings at cystometry, normal voiding parameters as well as following ICS & ICCS recommendations are the basis of successful testing
Is cystometry easy?