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

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

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

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” 1000-2000 B. C. Urodynamic is spelled wrong http://www.ics.org/

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

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

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

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

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)

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

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 0 100 200 300 400 500 600 EMG Pura Pves Pdet Pabd Qura Filling phase Voiding phase CP End Volume

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

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

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

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

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

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

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

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) = 38 + 2.5 × age (months) for infants < 1 year old

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 1998 81, 468-73

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

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?