Diagnostic Evaluation of Lower Urinary Tract Dysfunction

Victor W. Nitti, MD

Professor and Vice Chairman

Department of Urology

NYU School of Medicine

Lower Urinary Tract Function

• Storage of urine at low pressure to protect kidneys and assure continence

• Voluntary evacuation of urine

Lower Urinary Tract Function

• Can be viewed anatomically– Bladder– Outlet

• Can be viewed functionally– Storage– Voiding

Functional Classification ofVoiding Dysfunction

• Problem with emptying

• Problem with storage

• Either of the above may be due to– Bladder dysfunction– Bladder outlet or urethral dysfunction

*Wein, 1982

Lower Urinary Tract Symptoms

• Storage Symptoms– Frequency

– Urgency

– Incontinence• Stress

• Urgency

– Nocturia

– “Pain”

• Emptying Symptoms– Slow stream

– Need to strain

– Hesitancy

– Intermittency

– Feeling of incomplete emptying

Other Sequelae of LUT Dysfunction

• Urinary retention

• Recurrent UTI’s

• Hydronephrosis

• Renal insufficiency

Evaluation of Lower Urinary Tract Dysfunction

• History

• Physical

• Ancillary tests– Urine Analysis– PVR– Uroflow *– Diaries *– Pad test *

• Urodynamics

• Radiography

• Cystoscopy

Videourodynamics

History

• Symptoms– Characterization– Duration– Severity– Response to treatments or other factors– Effect of activities and QoL– Can use symptom scores

History

• Voiding Habits

• Fluid Intake

• Bowel habits

• Sleeping pattern

• Hematuria

• UTI’s

• Vaginal symptoms

History

• Urologic• Ob/Gyn• Neurologic• Medical / surgical• Social / psych• Radiation• Pelvic trauma• Medications

Physical ExamPhysical Exam

• Abdominal exam• Pelvic Exam

– vaginal mucosa• atrophy

– prolapse • assess 3 levels • presence/grade

• Muscular integrity – assess ability to squeeze– assess strength of squeeze

• Provocative stress test

Evaluation - Physical

• Rectal Exam– Tone– Posterior compartment prolapse– Rectal masses– Anal sphincter integrity

• Neurologic assessment– Overall coordination– MMS– Sensation– Reflexes

Urine Analysis

• UTI

• Hematuria

• Specific Gravity

• Proteinuria

• Glucosuria

Voiding and Intake Diaries

• Very useful tool to evaluate LUTS– Correlate history with reality

• Number of voids, incontinence episodes, urgency and severity, nocturia

• Assess fluid intake and urine output• Determine

– Avg. voided volume

– Max. voided volume

– Nocturnal vs. daytime urine production• Nocturnal polyuria

Voiding and Intake Diary(Frequency/Volume Chart)

Time Intake (cc) Output (cc) Comment Urgency? IncontinenceStress/Urgency

Pad Test

• Use when it is important to quantify the amount of urine loss

• Can be done under specific conditions, i.e. stress pad test, or to mimic typical day

• Stress pad test• 20 minute

• 1 hour

• 24 hour

Post Void Residual

• Excellent assessment of emptying

• Ultrasound (bladder scan) or catheterization

• Results may prompt further investigation

Uroflow

• Uroflowmetry with the measurement of PVR urine is recommended as a screening test for symptoms suggestive of urinary voiding dysfunction ($th ICI, 2008) *– Voiding symptoms– Elevated PVR– Results may prompt further investigation– Consider shape on curve not only Qmax, Qavg,

etc.

Normal Uroflow

Flattened or obstructed pattern Interrupted Pattern

Abdominal straining pattern

Cystoscopy

• LUT endoscopy highly recommended (4th ICI)– When initial testing suggest other pathologies, e.g.

hematuria– When pain or discomfort features in the patient’s

LUTS : these may suggest an intravesical lesion– When appropriate in the evaluation of

vesicovaginal fistula and extra-urethral urinary incontinence

Imaging

• Upper Urinary Tract– Renal Ultrasound

– CT scan

– MRI

• Lower Urinary Tract– MRI

– CT scan

– Cystography

• Pelvis– Ultrasound

• Transvaginal

• Abdominal

– CT scan

– MRI

Imaging

• Imaging of the upper urinary tract is highly recommended in specific situations (4th ICI, 2008)– Hematuria

– Neurogenic urinary incontinence e.g. myelodysplasia, spinal cord trauma,

– Incontinence associated with significant post-void residual

– Co-existing loin/kidney pain

– Severe pelvic organ prolapse, not being treated

– Suspected extra-urethral urinary incontinence

– Urodynamic studies which show evidence of poor bladder compliance

Role of Urodynamics• Level 1 evidenced-based “indications” for its use are surprising

lacking

• Difficult to conduct RCTs– For conditions where lesser levels of evidence and expert opinion

strongly suggest clinical utility

– Were “empiric treatment” is potentially harmful or even life-threatening (e.g. neurogenic voiding dysfunction)

• Symptoms can be caused by a number of different conditions and it is difficult to study pure or homogeneous patient populations

Role of Urodynamics

• Given the current state of evidence for UDS studies, what is most important is that the clinician has clear cut reasons for performing the study and that the information obtained will be used to guide treatment of the patient

• Therefore it is more useful to describe the role of UDS in clinical practice rather than precise “indications” for its use

Practical Use Of Urodynamics

• UDS is most useful when history, physical exam and simple tests are not sufficient to make an accurate diagnosis and/or institute treatment

Practical Use Of Urodynamics

• Clinical applicability in two general scenarios:

1. To obtain information needed to make an accurate diagnosis for what condition(s) is causing symptoms (e.g. lower urinary tract symptoms or incontinence)

2. To determine the impact of a disease that has the potential to cause serious and irreversible damage to the upper and lower urinary tract, sometime without symptoms• Neurological diseases, radiation cystitis

Role of UDS in Clinical Practice4th ICI, 2008

1. To identify or rule out factors contributing to lower urinary tract dysfunction (e.g. urinary incontinence) and assess their relative importance

2. To obtain information about other aspects of lower urinary tract function or dysfunction

3. To predict the consequences of lower urinary tract dysfunction on the upper urinary tract

Hosker G, et al : Dynamic Testing. In: Incontinence 4th International Consultation onIncontinence. United Kingdom, Health Publications, 2009, pp. 413-552.

Role of UDS in Clinical Practice4th ICI, 2008

4. To predict the outcome, including undesirable side effects, of a contemplated treatment

5. To confirm the effects of intervention or understand the mode of action of a particular type of treatment (especially a new one)

6. To understand the reasons for failure of previous treatments for symptoms (e.g. urinary incontinence) or for lower urinary tract function in general.

Hosker G, et al : Dynamic Testing. In: Incontinence 4th International Consultation onIncontinence. United Kingdom, Health Publications, 2009, pp. 413-552.

UrodynamicsPreparation

• Decide on questions to be answered before starting the study

• Design the study to answer these questions

• Customize the study as necessary

UrodynamicsGuidelines

• A study not duplicating symptoms when an abnormality is recorded is not diagnostic

• Failure to record an abnormality does not rule out its existence

• Not all abnormalities are clinically significant

UrodynamicsPhases of Micturition Cycle

• Storage or filling phase– Cystometrogram (CMG)– Provocative maneuvers

• ALPP• Urethral pressure measurements

• Emptying– Voiding pressure - flow study– Urethral sphincter or pelvic floor electromyography (EMG)– Post void residual

Cystometry

• CMG is measurement of the bladder’s response to filling

• Filling pressure

• Sensation

• Involuntary contractions

• Compliance

• Capacity

• Control over micturition

Idealized Normal Adult CMG

Pressure

Volume

Filling and Storage Voiding

Cystometry

• CMG only assesses the bladder’s response to filling

• Many abnormalities of filling and storage are caused by abnormalities of voiding

• If CMG alone is done, underlying problem maybe missed

CMG

Multichannel Urodynamics

Multichannel Urodynamics

• Bladder pressure monitoring (Pves)• Abdominal pressure monitoring (Pabd)• Subtracted detrusor pressure (Pdet)• Urethral pressure monitoring*• EMG• Voiding pressure / flow study

- Contractility - Pressure - flow relationship (obstruction) - Emptying

Urodynamic Parameters

• Filling and Storage– Sensation and capacity

– Involuntary detrusor contractions • Idiopathic detrusor overactivity• Neurogenic detrusor overactivity• May be spontaneous or provoked

Involuntary Detrusor Contractions

Urodynamic Parameters

• Filling and Storage– compliance

• ml/cm H20• Absolute pressure probably more important than a

compliance number or value• Storage pressures > 40 cm H2O known to be

harmful (McGuire, et al, 1981)• Impaired compliance usually a result of outlet

obstruction (anatomical or functional) or structural changes like radiation cystitis or TB

Impaired Compliance

Impaired Compliance + IDC

A Problem With Compliance:These two are not the same

mL mL

cmH2O cmH2O

50

400

Compliance = 8 ml/cmH2O

5

40

Compliance = 8 ml/cmH2O

Impaired Compliance

40 ml. 280 ml. 330 ml. 400 ml.

Pves = 40 cm H20

80 ml. 160 ml.

Impaired Compliance & IDC’s

Urodynamic Parameters

• Storage– Leak point pressures

• Abdominal or Valsalva (ALPP)• Bladder or detrusor (BLPP)

– Urethral pressure profile• MUP• MUCP

Abdominal Leak Point Pressure

• Abdominal pressure required to cause urinary incontinence in the absence of a detrusor contraction (AKA Valsalva LPP)

• Measure of intrinsic sphincter function– Ability of bladder outlet to resist changes in abdominal

pressure– Used to evaluate stress incontinence– Normal intrinsic sphincter function

• No leak at any physiologic Pabd• No “normal ALPP”

Leakage at arrow = ALPP = 109cmH2O

Detrusor Leak Point Pressure

• Detrusor pressure required to cause urinary incontinence in the absence of an increase in abdominal pressure (AKA Detrusor LPP)– Impaired compliance

– Involuntary contractions

• Bladder’s response to increased outlet resistance– DESD

– Other causes of bladder outlet obstruction

Leakage at arrow = BLPP = 45 cmH2O

Detrusor Leak Point Pressure

• DLPP > 40 cm H2O is potentially dangerous to the upper tracts!

Urodynamic Parameters

• Emptying– Obstruction or impaired contractility– Detrusor contractility– Sphincter coordination

• Bladder neck / internal sphincter• Striated sphincter

– DESD– Dysfunctional voiding

Neurophysiology of Micturition

• Normal voiding accomplished by activation of micturition reflex– Relaxation of striated urethral sphincter– Contraction of detrusor– Opening of vesical neck and urethra– Onset of urine flow

• Coordination between pontine and sacral micturition centers needed – Suprapontine input allows for voluntary control of the

micturition reflex

Sphincter Coordination

• DESD– Can only happen with neurological disease

• Suprasacral spinal cord

• “Pseudodyssynergia”– No neurological disease, a learned behavior

• Dysfunctional voiding

• Hinman syndrome

• Non-neurogenic neurogenic bladder

• Learned voiding dysfunction

DESD

Fill rate = 50 ml/min Fill rate = 25 ml/min

Urodynamics and Incontinence

Urodynamics For Incontinence

• When evaluating an incontinent patient determine what happens when the patient leaks

• Demonstrate incontinence on the study!

• Is the problem the bladder or the outlet or both?

Urodynamics: Stress Incontinence

• Uncertain diagnosis

• Mixed (urge and stress) symptoms

• Failed conservative treatment

• History of previous surgery

• Prior to surgical treatment of incontinence

Urodynamics: Stress Incontinence

• Prior to surgical treatment of incontinence– Documentation of stress incontinence if not seen on

physical exam

– Uncover occult instability or determine degree of instability in a patient with mixed incontinence

• Prognostic value

– Determination of ALPP or MUCP• May change surgical approach

– Detrusor contractility and voiding habits• Prognostic value

UDS in Female SUI:Literature- Based Practical Tips

• For women with pure SUI without urge symptoms who empty normally and demonstrate SUI on physical exam, UDS will not provide much useful information.

• For women with SUI who are considering surgical correction who have mixed symptoms or emptying difficulties UDS probably has its most significant role

UDS in Female SUI:Literature-Based Practical Tips

• Urethral function measurements of leak point pressures and urethral closure pressures should not used as a single factor to grade the severity of incontinence

• Use caution with the prediction of the outcome of any surgical treatment on the basis of contemporary urethral function tests

4th ICI Committee on Dynamic Testing 2009

Pathophysiology of SUI

ISDONLY

ISD

UrethralHypermobility

Urethral Hypermobility + ISD

All women with SUI have some degree of ISD because hypermobility often exists without SUI

What Is ISD?

• Portion or component of stress incontinence not caused by a support defect (urethral hypermobility)– Lack of coaptation– Deficiency of urethral musculature– Deficiency of submucosal layer– Neurological injury

Urodynamic Stress Incontinencewith hypermobility and ALPP = 109 cmH2OHow much ISD?

ALPP and ISDWhere Do The Numbers Come From?

• MUCP and ALPP measured in 125 women with SUI

• ALPP < 60 cmH2O– All had high grade (3) incontinence (81% continuous leakage)

– 75% fixed urethra

• ALPP 60-89 cmH2O– 80% pronounced type II urethral hypermobility and grade 2-3

incontinence

• ALPP > 90 cmH2O– Lesser grades of incontinence and minimal to gross

hypermobility (type I or II)

• ALPP unrelated to MUCP McGuire, et al J Urol 1993; 150:1452-1455

The Inference

• ALPP < 60 cmH2O = ISD• ALPP 60 - 90 cmH2O = equivocal, a component of

ISD• ALPP > 90-100 cmH2O little or no ISD

• But if no hypermobility, SUI must be caused by ISD

• Current technology does not permit a method to distinguish between ISD and hypermobility

Gravitational IncontinenceALPP = 34 cmH2OOpen bladder neckType 3 SUI

“Type 3 SUI”

Urethral Hypermobility vs. ISDFleischmann et al J Urol 169:999, 2003

• No correlation of ALPP with hypermobility:– ALPP < 60 24% hypermobile– ALPP 60-90 31% hypermobile– ALPP > 90 41% hypermobile

• No correlation of hypermobility or ALPP with number of incontinence episodes or pad weight

• ISD and hypermobility can coexist but do not define discrete classes of patients– Use parameters to characterize not classify

Urethral Pressure MeasurementsUPP – intraluminal pressure along length of urethra

• Maximal urethral pressure (MUP)– Maximum pressure of the

measured profile• Maximum urethral closure

pressure (MUCP)– Maximum difference

between the urethral and intravesical pressures

• Functional profile length– Length of the urethra along

which the urethral pressure exceeds the intravesical pressure in women

Urethral pressure profile

Urethral Pressure Profiles

Stress UPP - female UPP- male

Stress Induced Detrusor Overactivity

• Involuntary detrusor contraction preceded by an increase in abdominal pressure– Often occurs in conjunction with genuine stress

incontinence– AKA stress hyperreflexia

• Patients often complain of “stress incontinence” but usually with high volume loss of urine

• May respond to anticholinergics, but may also respond to treating stress incontinence

Stress Induced Detrusor Overactivity

SIDO SIDODO DO DO

Pdet

Pves

Pabd

Urodynamics: Urge Incontinence

• Failed empiric treatment– Especially in the elderly

• Young women– Occult neurological disease

• Associated neurological disease• Known condition that causes voiding dysfunction• Elevated PVR• Abnormal uroflow• Prior to invasive treatments

– Augmentation cystoplasty– Neuromodulation

Evaluation of Voiding Phase in Women With LUTS

Carlson et al J Urol 164:1614, 2000

• Abnormality of voiding phase - 44 (33%)

• Normal voiding - 58 (43%)• Unable to void - 32(24%)

• Mean age of women with abnormalities of voiding slightly lower 47.5 vs. 55.7 (p=0.022)

Voiding Phase Abnormalities

• Dysfunctional voiding 16• Obstruction from moderate cystocele 6• Primary vesical neck obstruction 6• DESD (initial presentation of neurological disease) 5• Obstruction after incontinence surgery 3• Obstructing urethral stricture 3• Impaired contractility 2• After contraction mimicking symptoms 2• Obstructing urethral diverticulum 1

Dysfunctional Voiding

37 year old woman in unable to void

• 1 year prior to presentation, found to have a distended bladder – asymptomatic retention

• On CIC 3-4 x/day, no spontaneous voiding• No neurological history or sx• No chronic medical problems• G0P0• Physical exam unremarkable• Renal ultrasound WNL• BUN and creatinine WNL• Cystoscopy and bladder bx’s normal

IDC VoidVoid

Videourodynamics

Uroflow 5 months after BN Incision

PVR = 16 ml

Outcome 3.5 years post TUI-BN

• Voiding spontaneously

• No CIC

• No significant LUTS

• Rare SUI with sneeze (not bothersome)

Qmax = 38.5 ml/sVoided volume = 459 mlPVR = 50 ml.

LUTS In Young WomenRosenblum et al, Int Urogynecol J, 2004;15:373-377

• Current practice is to avoid UDS in young women with primary complaint of frequency and urgency unless:– UUI– Elevated PVR– Abnormal uroflow– Failure to respond to tx

ME – 18 Year Old Female

• Also c/o frequency/urgency and daytime urge incontinence

• No other significant medical history

• PE unremarkable

• PVR minimal

ME – 18 Year Old Female

• Chief complaint nocturnal enuresis– Refractory to DDAVP and Imipramine– First episode at age 5– Intermittent throughout life– Currently wetting at least once/night

ME - Urodynamic Evaluation

50 ml/min 25 ml/min

Urge inc Void

80 ml 110 ml

Voiding

ME – 18 Year Old Female

• Based on urodynamics MRI on spine ordered

• Lipoma with tethered cord

• Diagnosis – detrusor hyperreflexia with DESD

Urodynamics in Pelvic Prolapse

• Can be useful to determine cause of symptoms– Storage and voiding symptoms

– Stress incontinence

• Preoperative evaluation– Occult stress incontinence

– Capacity

– Compliance

Rest Void

Rest Void

Cystocele reduced with pessary

No pessary Pessary

Start Void120 ml instilled

Radiation Cystitis