DO NOT MAKE IT DIFFICULTBy:Sunaryo Hardjowijoto, MD, PhDConsultant Urologist2006Presented at Basic Course For Surgery Trainee
URODYNAMICSThe study of pressure and flow relationships during the storage and transport of urine within the urinary tract.An objective investigation to clarify the symptoms.In routine practice mostly focused on the lower urinary tract.
Urodynamic investigations of the lower urinary tract:Investigation of bladder filling and voiding function Define bladder storage disorders Severely voiding dysfunction
LOWER URINARY TRACT:BladderUrethra Store urine adequatelyEmpty / expulse urine efficientlyVesicourethral unit:
The symptoms of vesicourethral unit dysfunction:Frequency / urgency (storage symptoms)IncontinenceSlow stream (voiding / emptying function)Urinary retention
The urinary bladder:Main function:Collection and low pressure storage of urineExpulsion of urine
Made up of 3 layers:Outer: adventitial (connective tissue) layerMiddle: smooth muscle with interlacing bundleOutermost: epithelium of transitional cell
The urethra in male:Posterior urethra, consists of:Pars prostaticaPars diaphragma
Anterior urethra, consists of:Pars bulbosaPars pendularis
The posterior urethra is utmost important for sphincteric mechanism:A proximal sphincter/bladder neck mechanismThe distal sphincter mechanism
In females:Bladder neck is weakerUrinary continence in women relies upon the integrity of intrinsic urethral sphincteric mechanism
Innervation of vesicourethral units:
The function of vesicourethral units:Storage of urine from the kidneysExpulsion of urine from the bladder
Urine storage:Intrinsic factor of bladder and urethra:Tonus of the muscle and connective tissue:Urethra: keeps the wall in apposition continenceBladder walls: exhibit receptive relaxation expands w.o. increasing pressure
Neural control:Stretch receptors posterior root of spinal cord lateral spinothalamic tracts brain (pontine micturition centre) desire to void
Expulsion of urine:Bladder filling reach the threshold (bladder capacity) afferent activity awareness of full bladderInitiation of voiding:Under the influence of pontine micturition centreRelaxation of: urethra pelvic floor muscles Funneling of the bladder neckProceed with detrusor contraction which is controlled by para sympathetic pathwayEnd of voiding closing of proximal urethra
In normal condition:Bladder capacity: 300 500 mlBladder filling pressure: 0 20 cmH2OBladder voiding pressure: 40 50 cmH2O (male) 30 40 cmH2O (female)Urethral closing pressure: 40 cmH2OUrethral voiding pressure: 0 - 20 cmH2O
Disorders of vesicourethral unit:Disorders of sensation:HypersensitiveHyposensitiveAbsent
Terminology of sensation:First sensation of fillingFirst desire to voidStrong desire to voidPain during filling or micturition
Disorders of vesicourethral unit:Disorders of motoric function:UnstableOveractiveUnderactiveAcontractile
Dysfunction of bladder outflow:Incompetent leakage w.o. detrusor contractionObstructive: overactivity mechanicalDyssynergia
Urodynamic techniques:Volume voided chartsPAD testingFlow rateIntravenous urodynamogramCystometryVideocystometrographyUrethral pressure measurementAmbulatory urodynamicsNeurological investigationWhitaker test
Volume voided charts:Volume/frequency chartVoiding diaryA simple noninvasive toolIts helps to:Define severity of symptomsObjectivize the history
Volume voided charts:Volume/frequencey chartVoiding diary
PAD testing:A simple noninvasive objective method for detecting and quantifiying urine leakageThe pad is weighed before and after test period (bending and could be extended)Test schedule:Start without voiding before Wear padFirst hour:Drink 500 ml within a short periodSit/rest 15 minsWalk 30 mins, climb stairsStand up from sitting 10 XHard coughing 10 XRun 1 minBend to pick up something on the floorWash hand in running tap waterAfter 1 hour pad is removed and weighedTest positive is uncreased 1,4 g/hour
Flowrate (= Flowmetry)Simplest and most often done investigation to assest voiding dysfunctionA noninvasive examinationTo confirm the presence of B.O obstructionResult of examination is influenced by:Detrusor contractilityRelaxation of sphincterPatency of the urethra
The FlowmeterA device that measures and indicates quantity of fluid passing through the machine per unit timeTypes of flowmeters:Rotating diskElectronic dipstickGravimetricThe expressed unit: ml/s
The important parameters:Volume voidedRate: maximal averagePattern:ContinousNormalFastProlongedIntermittent
Flow rate are influenced by:Volume voided: > 150 ml - < 600 mlAgeSexSurroundings
The Terminology in Flow Rate:Voided volumeMaximum flow rate (Q max)Average flow rateFlow time (T)T to Q maxVoiding timeIntermittent flow
The graphic of urine flow:
The patterns of flow rate
CystometryA method used to measure the relationships between pressure and volume of the bladderMeasurement of detrusor pressure during filling and voidingCould assess:Bladder complianceSensationStabilityCapacity
Normal cystometrogram
Video cystometrography
The radiologic examination provides additional information on:The bladder anatomyThe presence of V.U. refluxThe level of outflow obstructionThe support of the bladder base during coughing
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