Bladder problems are not always as straightforward as they appear.

Two people may both complain of urinary urgency, leakage or difficulty emptying their bladder, yet the underlying causes can be completely different. One bladder may be contracting when it should be relaxing, another may not contract strongly enough, and sometimes the bladder is behaving perfectly well while the outlet is causing all the trouble.

This is where urodynamic studies, often simply called urodynamics, can help.

Think of urodynamics as a stress test for the bladder. Rather than simply looking at its anatomy, we observe how the bladder fills, stores urine and empties while simultaneously measuring pressures, urine flow and sometimes pelvic floor activity.

The aim is not merely to produce a collection of colourful graphs. The important question is:

What is the bladder actually doing, and will knowing this change the treatment?

What Are Urodynamic Studies?

Urodynamics refers to a group of tests that assess the function of the bladder, urethra and urinary sphincter.

Depending on the clinical situation, testing may evaluate:

• How much urine the bladder can comfortably hold
• Bladder sensation during filling
• Whether the bladder remains relaxed while filling
• Whether involuntary bladder contractions occur
• Whether urinary leakage occurs and why
• The pressure required to store urine
• The strength of the bladder muscle during urination
• Whether there is obstruction to urinary flow
• Whether the bladder empties completely
• How the urinary sphincter and pelvic floor behave during filling and voiding

Urodynamics therefore investigates function rather than simply structure.

An ultrasound or cystoscopy may show us what the urinary tract looks like. Urodynamics tells us what it is doing.

Who May Need Urodynamic Testing?

Not every patient with urinary symptoms requires urodynamics.

For many straightforward urinary problems, the diagnosis can be made from the history, examination, bladder diary, urine testing, flow studies and ultrasound.

Urodynamics becomes particularly useful when the diagnosis is uncertain, symptoms are complex, previous treatments have failed, neurological disease is present, or an invasive treatment is being considered where understanding bladder function may alter the choice of treatment.

Common indications include:

Urinary Incontinence

Urodynamics may be useful when assessing:

• Stress urinary incontinence
• Urgency urinary incontinence
• Mixed urinary incontinence
• Persistent leakage following previous continence surgery
• Incontinence following prostate surgery
• Complex or unexplained urinary leakage

In straightforward female stress urinary incontinence, urodynamics is not necessarily required before treatment. It becomes more useful when symptoms and clinical findings do not agree or when there are complicating factors.

Overactive Bladder

Patients with overactive bladder may experience:

• Urinary urgency
• Frequent urination
• Nocturia
• Urgency urinary incontinence

Urodynamics can sometimes demonstrate detrusor overactivity, where the bladder muscle contracts involuntarily during filling.

Importantly, a normal urodynamic study does not necessarily exclude overactive bladder. Symptoms and urodynamic findings do not always travel together.

Difficulty Emptying the Bladder

Patients may report:

• Poor urinary flow
• Hesitancy
• Straining
• Intermittent flow
• Incomplete emptying
• Urinary retention

The challenge is determining why.

Is there an obstruction?

Or is the bladder muscle simply not contracting strongly enough?

The symptoms can look remarkably similar, but the treatments can be very different.

Men With Lower Urinary Tract Symptoms

In men with prostate enlargement, urodynamics may help distinguish between:

Bladder outlet obstruction

and

Detrusor underactivity, where the bladder muscle has insufficient strength to empty effectively.

This distinction may be particularly valuable before prostate surgery when there is uncertainty about whether removing the obstruction will improve urinary flow.

Neurological Bladder Dysfunction

Urodynamics has an especially important role in patients with neurological conditions such as:

• Spinal cord injury
• Multiple sclerosis
• Parkinson’s disease
• Spina bifida
• Stroke
• Certain spinal disorders

In these patients, we are interested not only in urinary symptoms but also in whether bladder pressures could potentially damage the kidneys.

Before or After Certain Urinary Procedures

Urodynamics may also be considered:

• Before complex continence surgery
• Following unsuccessful continence surgery
• Before some bladder outlet procedures
• Following prostate surgery when symptoms persist
• When considering treatments such as bladder Botox or sacral neuromodulation in selected complex patients

What Happens During a Urodynamic Study?

The test is usually performed as an outpatient procedure.

It generally takes approximately 30–60 minutes, although this varies depending on the type of study being performed.

You can usually eat, drink and take your normal medications unless specifically instructed otherwise.

Step 1: Arriving With a Comfortably Full Bladder

You may be asked to arrive with a reasonably full bladder.

You will urinate into a special toilet called a uroflowmeter.

This measures:

• Urine volume
• Maximum urinary flow rate
• Average flow rate
• The shape of the urinary flow curve
• How long urination takes

An ultrasound may then measure how much urine remains in the bladder.

This is called the post-void residual.

Step 2: Placement of Small Catheters

A very fine catheter is gently passed through the urethra into the bladder.

A second small pressure catheter is usually placed into the rectum, or occasionally the vagina.

Why two pressure measurements?

Because pressure inside the abdomen affects pressure inside the bladder.

By measuring both, the computer can calculate the pressure generated specifically by the bladder muscle:

Detrusor pressure = bladder pressure − abdominal pressure

This simple equation sits at the heart of conventional urodynamics.

Step 3: Filling the Bladder

The bladder is slowly filled with sterile fluid.

During filling, you will be asked to describe what you feel.

We may record:

• First sensation of bladder filling
• First desire to urinate
• Strong desire to urinate
• Maximum bladder capacity

The pressure inside the bladder is continuously monitored.

Normal filling cystometrogram

Normal filling cystometrogram. During filling, the bladder accommodates increasing volume while detrusor pressure (Pdet) remains relatively stable. Coughs cause corresponding rises in Pves and Pabd without a true detrusor contraction. Sensations such as first sensation, first desire and strong desire can be marked on the tracing.

 

Step 4: Provocative Testing

You may be asked to:

• Cough
• Strain
• Stand
• Change position
• Listen to running water

These manoeuvres are not designed to make the test unnecessarily theatrical. They help reproduce the circumstances under which your symptoms normally occur.

If urinary leakage occurs during coughing without an involuntary bladder contraction, this may demonstrate urodynamic stress incontinence.

Step 5: Voiding

Once the bladder is comfortably full, you will be asked to urinate.

During urination we simultaneously measure:

• Urinary flow
• Bladder pressure
• Abdominal pressure
• Detrusor pressure

This is called a pressure-flow study.

It can be extremely useful when determining whether poor urinary flow is caused by obstruction or weak bladder contraction.

What Does Urodynamics Measure?

Bladder Sensation

We assess when you first become aware that the bladder is filling and when the desire to urinate becomes stronger.

Sensation may be:

• Normal
• Increased
• Reduced
• Absent

Abnormal bladder sensation may occur in several neurological and functional bladder disorders.

Bladder Capacity

The amount of urine the bladder can comfortably hold is measured.

A small functional capacity may occur with conditions such as severe urgency or bladder hypersensitivity, although capacity must always be interpreted in clinical context.

Bladder Compliance

A healthy bladder should behave rather like a flexible reservoir.

As it fills, its volume should increase without a major rise in pressure.

Poor bladder compliance means pressure rises excessively as the bladder fills.

This is particularly important in some neurological bladder disorders because persistently elevated storage pressures can potentially threaten the upper urinary tract.

Detrusor Overactivity

If the bladder muscle contracts involuntarily during filling, this is called:

Detrusor overactivity.

It may be associated with:

• Urgency
• Urgency incontinence
• Frequency
• Nocturia

When associated with an underlying neurological condition, it may be described as neurogenic detrusor overactivity.

Examples of terminal, phasic, wet and dry detrusor overactivity.

Detrusor overactivity. During bladder filling there is an involuntary increase in Pdet that cannot be explained by a corresponding increase in abdominal pressure. The contraction may be associated with urgency and, when leakage occurs, urgency urinary incontinence.

View the LABORIE-based detrusor-overactivity tracings

Stress Urinary Incontinence

If urine leaks when coughing or straining without a detrusor contraction, this supports a diagnosis of:

Urodynamic stress incontinence.

Additional measurements such as leak-point pressures may occasionally contribute to assessment in selected patients.

Bladder Outlet Obstruction

During urination, a pattern of:

High bladder pressure + low urinary flow

may suggest obstruction.

In men, benign prostate enlargement is a common cause.

Other causes include:

• Urethral stricture
• Bladder neck obstruction
• Previous continence surgery
• Dysfunctional voiding

Bladder outlet obstruction: pressure-flow study

Bladder outlet obstruction. During voiding the bladder generates a relatively high detrusor pressure, but urinary flow remains reduced. This high-pressure, low-flow relationship is characteristic of increased bladder outlet resistance.

In men, pressure-flow studies allow calculation of the Bladder Outlet Obstruction Index (BOOI):

BOOI = PdetQmax − 2(Qmax)

For men, BOOI >40 is generally classified as obstructed, 20–40 as equivocal and <20 as unobstructed.

Detrusor Underactivity

Sometimes the urinary flow is poor because the bladder muscle does not generate sufficient pressure.

This is known as:

Detrusor underactivity.

This distinction matters.

Operating on the prostate of a patient whose main problem is a very weak bladder may not produce the expected improvement in urinary flow.

Urodynamics can therefore occasionally prevent us from treating the wrong end of the plumbing.

Dysfunctional Voiding

Some patients involuntarily contract their pelvic floor or urinary sphincter while attempting to urinate.

Instead of the outlet opening smoothly, it intermittently closes.

Pelvic floor electromyography may help identify this pattern in selected patients.

Understanding the Urodynamic Tracing

A urodynamic report typically contains several pressure and flow curves.

At first glance, the tracing can resemble an enthusiastic seismograph.

The important measurements usually include:

Pves: pressure measured inside the bladder.

Pabd: pressure measured within the abdomen.

Pdet: pressure generated by the bladder muscle.

Flow: the rate at which urine leaves the bladder.

The relationship between these measurements allows us to understand what is happening during bladder filling and emptying.

Common Findings and What They May Mean for Treatment

Urodynamic Finding	Possible Interpretation	Potential Treatment Direction
Normal storage and emptying	Normal urodynamic study	Treatment guided by symptoms and other investigations
Detrusor overactivity	Overactive bladder physiology	Bladder training, medication, Botox, neuromodulation
Stress leakage	Stress urinary incontinence	Pelvic floor therapy, bulking agents, sling or other continence surgery
High pressure + low flow	Bladder outlet obstruction	Treatment of obstruction where appropriate
Low pressure + low flow	Detrusor underactivity	Emptying strategies, intermittent catheterisation or selected treatments
Poor compliance	High-pressure storage	Pressure-reducing treatment and upper urinary tract surveillance
Pelvic floor activation during voiding	Dysfunctional voiding	Pelvic floor physiotherapy/biofeedback
Significant residual urine	Incomplete bladder emptying	Identify obstruction versus impaired bladder contraction

The urodynamic result is not a treatment plan by itself.

It must be interpreted alongside symptoms, examination findings, bladder diaries, ultrasound, cystoscopy and other investigations where appropriate.

How Urodynamics Can Guide Treatment

If Detrusor Overactivity Is Found

Initial treatment may include:

• Bladder training
• Fluid modification
• Pelvic floor physiotherapy
• Antimuscarinic medication
• Beta-3 agonist medication

For persistent symptoms, options may include:

• Intravesical Botox injections
• Sacral neuromodulation
• Other specialist treatments in selected patients

If Stress Incontinence Is Demonstrated

Treatment depends on severity, sex, previous surgery and individual circumstances.

Options may include:

• Pelvic floor rehabilitation
• Continence devices
• Peri-urethral bulking agents
• Sling procedures
• Colposuspension in selected women
• Male sling following prostate surgery
• Artificial urinary sphincter in appropriate men

If Bladder Outlet Obstruction Is Demonstrated

Treatment depends on the underlying cause.

For benign prostate enlargement, options may include:

• Medication
• Minimally invasive prostate treatments
• Laser prostate surgery
• Transurethral prostate surgery
• Other surgical procedures appropriate to prostate size and anatomy

A urethral stricture or bladder neck obstruction requires a different treatment strategy.

If the Bladder Muscle Is Weak

Treatment may involve:

• Double voiding
• Timed voiding
• Reviewing medications
• Treating reversible causes
• Intermittent self-catheterisation when necessary
• Long-term catheterisation in selected circumstances
• Sacral neuromodulation in carefully selected patients with non-obstructive urinary retention

The key issue is avoiding unnecessary outlet surgery when obstruction is not actually the problem.

If Bladder Storage Pressures Are High

This is particularly important in neurological bladder disease.

Treatment may include:

• Medication
• Intermittent catheterisation
• Intravesical Botox
• Regular renal imaging
• Monitoring kidney function
• Repeat urodynamic assessment
• Reconstructive bladder surgery in uncommon severe cases

Here the objective extends beyond improving symptoms. We may also be trying to protect kidney function over the long term.

Are Urodynamic Studies Uncomfortable?

Most patients tolerate the investigation well.

Passing the small catheter can cause brief discomfort, and there may be some mild burning when urinating afterwards.

Having an audience while your bladder performs under laboratory conditions is admittedly not anyone’s preferred afternoon entertainment, but the clinical staff performing these studies do this routinely and will make the process as private and comfortable as possible.

Possible Side Effects and Complications

Urodynamic testing is generally safe.

Possible side effects include:

• Temporary burning during urination
• Urinary urgency
• Minor urethral discomfort
• A small amount of blood in the urine
• Urinary tract infection
• Temporary difficulty urinating

Significant complications are uncommon.

Patients should seek medical advice if they develop fever, chills, worsening urinary symptoms, significant bleeding or an inability to urinate following the test.

Does Everyone With Bladder Symptoms Need Urodynamics?

No.

This is an important point.

Urodynamics should generally be performed when the result is likely to answer a clinically relevant question or potentially alter management.

The investigation is particularly valuable when:

• Symptoms are complex
• The diagnosis remains uncertain
• Symptoms and examination findings disagree
• Previous treatment has failed
• Neurological bladder dysfunction is suspected
• There is significant urinary retention
• Complex surgery is being considered
• Understanding bladder pressure or contractility could change treatment

Testing simply because “we haven’t done one yet” is not a particularly compelling indication.

Urodynamics: Turning Symptoms Into Physiology

Patients often arrive describing urgency, leakage, poor flow or difficulty emptying their bladder.

These symptoms tell us what is happening.

Urodynamics can sometimes tell us why.

By measuring how the bladder stores and releases urine, we can distinguish between problems involving the bladder muscle, urinary sphincter, pelvic floor and bladder outlet.

Most importantly, urodynamics can help ensure that treatment is directed at the underlying problem rather than simply the symptom.

The Bottom Line

Urodynamics is not necessary for every bladder problem. But when the diagnosis is uncertain or treatment decisions depend on understanding bladder function, it can provide exceptionally useful information.

A good urodynamic study does more than generate graphs.

It helps answer the question that matters most:

What treatment is most likely to work for this particular bladder?

This information is intended for general patient education and does not replace individual medical assessment. The need for urodynamic testing and interpretation of results should be discussed with your treating urologist or continence specialist.

So, if you have incontinence symptoms and they are bothersome and you have tried pelvic floor rehabilitation and at least 2 of the available drugs for overactive bladder with no results, come see you friendly Brisbane Urologist, Uro-Jo to assist you in regaining continence and confidence.

Urinary incontinence and bladder control problems can have a significant effect on everyday life. Frequent trips to the toilet, sudden urgency, leakage, waking repeatedly at night or being unable to empty the bladder properly can interfere with work, exercise, travel, sleep and social activities.

For men and women whose symptoms have not responded adequately to conservative treatment or medication, sacral neuromodulation (SNM) can provide another treatment option.

Sacral neuromodulation is particularly useful because it can treat two apparently opposite bladder problems:

• an overactive bladder, where the bladder signals too frequently or contracts when it should not; and
• an underactive bladder or non-obstructive urinary retention, where the bladder does not empty effectively.

Rather than operating directly on the bladder, sacral neuromodulation works by modifying the nerve signals involved in bladder storage and emptying.

What is sacral neuromodulation?

The bladder, urethral sphincter, pelvic floor and brain communicate through a complex network of nerves. The sacral nerves, particularly those arising from the S3 region, form an important part of this communication system.

Sacral neuromodulation uses a small, implanted device to deliver mild electrical impulses to a sacral nerve. These impulses help modify abnormal signaling between the bladder, pelvic floor, spinal cord and brain.

A useful way of thinking about the treatment is that it attempts to recalibrate the communication system controlling the bladder, rather than simply forcing the bladder to contract or relax.

International Continence Society guidance recognises sacral neuromodulation as an established therapy for refractory urinary urgency and frequency, urgency urinary incontinence and non-obstructive urinary retention.

Importantly, SNM does not “cure” every patient with urinary incontinence. The aim is to achieve a meaningful and sustained reduction in symptoms and improvement in quality of life.

What conditions can sacral neuromodulation treat?

1. Overactive bladder

Overactive bladder (OAB) is characterised by urinary urgency, usually accompanied by increased frequency and nocturia, with or without urgency urinary incontinence.

Typical symptoms include:

• suddenly needing to pass urine;
• difficulty postponing urination;
• frequent urination during the day;
• waking several times at night to urinate;
• urinary leakage associated with urgency; and
• needing to know where the nearest toilet is whenever leaving home.

Some patients experience urgency and frequency without leakage, while others develop urgency urinary incontinence, where the urge is followed by involuntary loss of urine.

Sacral neuromodulation can be considered when symptoms remain troublesome despite appropriate conservative and/or medical treatment. Current AUA/SUFU guidance includes SNM among the minimally invasive treatment options that clinicians should offer to appropriately selected patients with OAB who have not achieved adequate improvement with behavioural or pharmacological therapy.

2. Urgency urinary incontinence

Urgency urinary incontinence is leakage associated with a sudden compelling desire to urinate.

This is different from stress urinary incontinence, where leakage occurs with coughing, sneezing, exercise or physical exertion.

Sacral neuromodulation is principally a treatment for urgency-related leakage. It is not a standard treatment for isolated stress urinary incontinence.

This distinction is particularly important in women who may have both stress and urgency incontinence and in men who develop stress incontinence following prostate surgery.

When both types of leakage are present, treatment needs to be tailored to determine which component is causing the greatest problem.

What about an underactive bladder?

The bladder does not always misbehave by being too active. Sometimes the problem lies at the other end of the spectrum.

Underactive bladder and urinary retention

An underactive bladder describes symptoms associated with inadequate bladder emptying, often related to reduced bladder contractility or impaired coordination between the bladder and urinary sphincter.

Symptoms can include:

• difficulty starting urination;
• a slow or interrupted urinary stream;
• prolonged urination;
• straining to urinate;
• feeling that the bladder has not emptied;
• recurrent urinary tract infections;
• a large residual volume of urine after voiding; and
• complete inability to empty the bladder without a catheter.

Some patients need to perform clean intermittent self-catheterisation several times each day.

However, poor bladder emptying does not automatically mean that sacral neuromodulation is appropriate.

Obstruction must first be excluded

In men, urinary retention may be caused by:

• benign prostate enlargement;
• urethral stricture;
• bladder neck obstruction; or
• scarring following previous prostate or urethral surgery.

In women, causes can include:

• previous continence surgery;
• urethral obstruction;
• pelvic organ prolapse; or
• functional outlet obstruction.

Sacral neuromodulation is primarily used for non-obstructive urinary retention rather than retention caused by a mechanical blockage.

The distinction may require urine flow testing, measurement of the post-void residual, cystoscopy and, in selected patients, urodynamic studies.

The AUA notes that sacral neuromodulation can be used in appropriately selected men and women with non-obstructive urinary retention, including patients with decreased bladder contractility.

Who may benefit from sacral neuromodulation?

SNM may be considered in appropriately selected men and women with:

• refractory overactive bladder;
• urinary urgency and frequency;
• urgency urinary incontinence;
• non-obstructive urinary retention;
• impaired bladder emptying in selected patients; or
• troublesome bladder dysfunction that has not responded adequately to other treatments.

In Australia, sacral neuromodulation is an established treatment option. The TGA describes implantable sacral nerve stimulation systems as devices used in conditions including overactive bladder, urinary retention and urinary incontinence.

It is generally not a first-line treatment. Australian TGA information relating to the InterStim X system specifically notes that the treatment is not first-line therapy and is intended for appropriately selected patients after conservative and medical management have been attempted.

What treatments are usually tried first?

The treatments used before considering SNM depend upon the underlying bladder problem.

For overactive bladder these may include:

• bladder retraining;
• modification of fluid and caffeine intake;
• pelvic floor physiotherapy;
• management of constipation and other contributing factors;
• antimuscarinic medication;
• beta-3 agonist medication;
• posterior tibial nerve stimulation; and
• bladder injections with botulinum toxin (Botox).

For an underactive bladder or urinary retention, treatment may include:

• treating an identifiable obstruction;
• reviewing medications that may impair bladder emptying;
• timed or double voiding in selected patients; and
• intermittent self-catheterisation.

The appropriate pathway varies considerably between patients.

Assessment before sacral neuromodulation

Successful treatment begins with establishing the correct diagnosis.

Assessment may include:

Medical history

Your urologist will establish whether the predominant problem is urgency, frequency, leakage, difficulty emptying the bladder or a combination of symptoms.

Bladder diary

A bladder diary can record:

• how frequently you urinate;
• urine volumes;
• fluid intake;
• urgency episodes;
• leakage episodes; and
• night-time urination.

Urine testing

Urinary infection should be excluded where appropriate.

Post-void residual measurement

An ultrasound can measure how much urine remains in the bladder after urination.

Uroflowmetry

Urinary flow testing can provide useful information about the strength and pattern of the urinary stream.

Cystoscopy

A cystoscopy may be required when obstruction, urethral narrowing, prostate-related obstruction or another bladder abnormality is suspected.

Urodynamic studies

Urodynamic testing is not required in every patient, but it can be particularly valuable when the diagnosis is uncertain, symptoms are complex, previous treatments have failed or poor bladder emptying needs further investigation.

How is sacral neuromodulation performed?

One of the most attractive features of sacral neuromodulation is that the treatment can usually be tested before committing to a permanent implant.

The procedure therefore generally takes place in two stages.

Stage 1: The test phase

A thin electrode or tined lead is positioned through a small opening in the sacrum adjacent to a sacral nerve, most commonly the S3 nerve root.

The position is confirmed using anatomical landmarks, imaging and appropriate physiological responses during the procedure.

The lead is then connected to an external stimulator.

The patient goes home and uses the system during a trial period while recording symptoms in a bladder diary.

Depending upon the reason for treatment, we look for improvements such as:

• fewer urgency episodes;
• fewer episodes of urinary leakage;
• reduced urinary frequency;
• fewer night-time toilet visits;
• improved bladder emptying;
• lower residual urine volumes; or
• reduced need for intermittent catheterisation.

A meaningful improvement during the test phase, commonly around 50% or greater improvement in the target symptoms, is generally used to determine whether proceeding to permanent implantation is worthwhile.

Stage 2: Permanent implantation

If the trial is successful, a small pulse generator is implanted beneath the skin, usually in the upper buttock.

The device is connected to the previously positioned sacral lead.

Once the incision has healed, the device remains beneath the skin and is generally not visible, although a small contour may sometimes be noticeable.

The stimulator is programmed to provide electrical impulses tailored to the individual patient.

Patients are provided with a programmer or controller that allows appropriate adjustments within parameters established by the treating team.

What does the stimulation feel like?

Patients may notice a mild:

• tingling;
• tapping;
• pulling; or
• vibration-like sensation

in the pelvic, perineal, vaginal, scrotal or anal region.

The stimulation should not normally be painful.

The device can be reprogrammed during follow-up if symptoms change or stimulation becomes uncomfortable.

How successful is sacral neuromodulation?

Success depends on the condition being treated, patient selection and how success is defined.

The major advantage of SNM is that each patient effectively undergoes their own therapeutic trial before receiving the permanent implant.

For refractory overactive bladder, clinical studies demonstrate substantial improvement in appropriately selected patients. The 2024 AUA/SUFU guideline cites a randomised study in which 86% of patients allocated to SNM initially responded and 61% met the study’s definition of therapeutic success at six months.

For non-obstructive urinary retention, treatment may substantially improve bladder emptying and can reduce or sometimes eliminate the need for intermittent catheterisation in responders. AUA evidence reviewing SNM for non-obstructive retention reported a significant reduction in post-void residual urine following treatment.

Individual results vary, and improvement rather than complete cure is a more realistic treatment goal.

Sacral neuromodulation versus Botox

Both sacral neuromodulation and intravesical botulinum toxin are established advanced treatments for refractory overactive bladder.

Botox is injected into the bladder wall during cystoscopy and temporarily reduces excessive bladder contractions.

SNM instead modifies the neural pathways controlling bladder function.

Both can be effective. One practical difference is that Botox usually needs to be repeated as its effect wears off, whereas SNM uses an implanted device designed to provide ongoing treatment.

Botox also carries a risk of urinary retention and urinary tract infection. In the ROSETTA trial, women treated with botulinum toxin had higher rates of urinary tract infection and temporary catheterisation than those treated with SNM, although both treatments produced substantial improvement in urgency incontinence.

The best option depends upon the individual patient’s priorities and bladder function.

Advantages of sacral neuromodulation

Potential advantages include:

• treatment can be tested before permanent implantation;
• no major bladder reconstruction is required;
• it can reduce urgency and urgency incontinence;
• it can improve frequency and nocturia in selected patients;
• it may improve bladder emptying in non-obstructive retention;
• it may reduce dependence on intermittent catheterisation;
• stimulation can be individually programmed;
• treatment is adjustable over time; and
• the system can be removed if necessary.

Perhaps most importantly, SNM offers another option when conventional treatment has failed but major reconstructive surgery is undesirable.

What are the risks and possible complications?

Sacral neuromodulation is a surgical procedure and complications can occur.

These include:

• pain or discomfort around the implant;
• wound infection;
• bleeding or bruising;
• lead movement or migration;
• loss of effective stimulation;
• uncomfortable stimulation;
• change in the location of the stimulation sensation;
• failure to achieve adequate symptom improvement;
• technical problems with the lead or pulse generator;
• need for reprogramming;
• battery depletion; and
• need for revision, replacement or removal of the device.

In studies of SNM for overactive bladder, recognised device-related adverse events have included changes in stimulation, implant-site pain and infection.

Modern systems have improved considerably, but patients should understand that implantation begins a long-term relationship with the device rather than being a one-off operation.

What happens if the treatment stops working?

A reduction in benefit does not necessarily mean that the treatment has permanently failed.

The first step is often to check the device and change its programming.

If this does not restore benefit, further investigation may determine whether there has been:

• lead migration;
• lead damage;
• battery depletion;
• a change in bladder function; or
• another underlying urinary problem.

Occasionally, surgical revision or replacement of the lead or pulse generator is required.

Battery life and rechargeable devices

Different sacral neuromodulation systems and pulse generators are available, including rechargeable and non-rechargeable technologies.

Battery longevity depends on the particular device and the stimulation settings required.

A non-rechargeable generator eventually requires surgical replacement when its battery reaches the end of its useful life.

Rechargeable systems can potentially reduce the frequency of generator replacement but require the patient to recharge the device periodically.

The most appropriate system depends on factors such as age, lifestyle, dexterity, expected stimulation requirements and patient preference.

What about MRI scans?

MRI compatibility has historically been an important issue for patients with implanted neuromodulation devices.

Many modern SNM systems now provide substantially broader MRI access than older devices. However, MRI eligibility depends on the exact pulse generator, lead and implanted system.

Patients should therefore keep their implant identification information and tell radiology staff that they have a sacral neuromodulation device before undergoing an MRI.

Is sacral neuromodulation suitable for both men and women?

Yes.

Although much of the early research into urgency urinary incontinence involved women, sacral neuromodulation can be used in appropriately selected men and women.

In men, it is particularly important to distinguish non-obstructive bladder dysfunction from obstruction caused by prostate enlargement, urethral stricture or previous prostate surgery.

In women, pelvic organ prolapse and previous continence or pelvic surgery may also need to be considered.

The treatment therefore depends much more on the type of bladder dysfunction than on the patient’s sex.

Overactive versus underactive bladder: one treatment, two different problems

It can initially seem strange that the same treatment can help a bladder that is too active and one that does not empty adequately.

This is because sacral neuromodulation is not simply an electrical switch telling the bladder to contract or relax.

Instead, it modifies the complex sensory and motor signalling involved in bladder storage, awareness, pelvic floor coordination and emptying.

For an overactive bladder, this can reduce inappropriate urgency and bladder activity.

For non-obstructive urinary retention or selected underactive bladder dysfunction, neuromodulation may improve the coordination of the bladder outlet and neural pathways involved in effective voiding.

This ability to influence both storage and emptying disorders makes sacral neuromodulation unusual among treatments for lower urinary tract dysfunction.

When should sacral neuromodulation be considered?

Sacral neuromodulation may be worth discussing when:

Overactive bladder symptoms remain troublesome despite conservative and medical treatment

or

Non-obstructive urinary retention is causing significant symptoms or dependence on intermittent catheterisation.

The key is appropriate patient selection.

Before proceeding, it is important to establish why the bladder is malfunctioning. In particular, a mechanical obstruction should not be mistaken for an underactive bladder.

Once the diagnosis is established, the test phase provides a valuable opportunity to determine whether neuromodulation is likely to provide meaningful benefit before committing to a permanent implant.

The bottom line

Sacral neuromodulation is an established, minimally invasive surgical treatment for selected men and women with refractory overactive bladder, urgency urinary incontinence and non-obstructive urinary retention.

A small electrode placed near the sacral nerves modifies the neural signals involved in bladder storage and emptying. Because treatment is usually performed as a staged procedure, patients can assess their response during a test phase before deciding whether to proceed with permanent implantation.

For patients who have spent years planning their lives around the nearest toilet, coping with unpredictable leakage or relying on catheters to empty their bladder, sacral neuromodulation can offer a very different approach: treating the communication network controlling the bladder rather than simply treating the bladder itself.

Important information

This information is intended for general patient education and does not replace individual medical advice. The suitability of sacral neuromodulation depends on the cause of the bladder dysfunction, previous treatments, medical history and individual treatment goals. Assessment by a urologist with experience in urinary incontinence and voiding dysfunction is recommended.

So, if you think is something that may work for you, come see me at my rooms in Brisbane, Caboolture or Bribie Island. Your friendly Brisbane based Urologist, Dr Jo Schoeman will assist.

Stress urinary incontinence (SUI) is one of the most common forms of urinary incontinence in women. It occurs when urine leaks because pressure inside the abdomen rises faster than the urethra and pelvic floor can close.

Coughing, sneezing, laughing, lifting, running, jumping and exercise can all trigger leakage. For some women the leakage is only a few drops; for others it can be substantial enough to interfere with exercise, work, intimacy and everyday life.

The good news is that SUI is treatable, and treatment can be tailored to the severity of symptoms, the woman’s lifestyle and preferences, previous surgery, pelvic floor function and other bladder symptoms.

What are the symptoms and signs of stress urinary incontinence?

The classic symptom is involunta

ry urine leakage with physical exertion.

Common triggers include:

• Coughing or sneezing
• Laughing
• Getting up from a chair
• Lifting children or heavy objects
• Running or jumping
• Exercise, particularly high-impact exercise
• Sexual intercourse
• Changes in position
• Sports such as tennis, running or aerobics

Some women notice only occasional leakage, while others need pads every day.

Stress incontinence versus urgency incontinence

It is important to distinguish SUI from urgency urinary incontinence, where urine leakage follows a sudden, difficult-to-defer urge to urinate.

Many women have mixed urinary incontinence, with both stress and urgency leakage.

This distinction matters because the treatment strategy can be quite different. Treating the wrong component first can produce disappointing results.

How is stress urinary incontinence diagnosed?

For many women, the diagnosis can be made from the history and examination without an extensive battery of tests.

A specialist assessment usually includes:

1. Medical history

Your doctor will ask about:

• The nature and severity of leakage
• What activities trigger leakage
• Urinary urgency and frequency
• Night-time urination
• Recurrent urinary tract infections
• Previous pregnancies and childbirth
• Menopause and hormonal symptoms
• Previous pelvic or continence surgery
• Pelvic-organ prolapse
• Neurological conditions
• Medications
• Impact on exercise, work, social activities and sexual function

2. Bladder or voiding diary

A bladder diary records fluid intake, urinary frequency, urine volumes, urgency episodes and leakage over several days.

It can be surprisingly revealing. It helps determine whether the problem is predominantly stress leakage, urgency, excessive fluid intake, frequent small-volume voiding or a combination of these.

3. Physical examination

A pelvic examination can assess:

• Pelvic organ prolapse
• Pelvic floor muscle strength
• Urethral mobility
• Vaginal and vulval health
• Atrophic changes associated with menopause
• Evidence of previous surgery

A cough stress test may be performed with a comfortably full bladder. Leakage of urine through the urethra during coughing supports the diagnosis of stress urinary incontinence.

4. Urine testing

A urine test is often appropriate, particularly when there are symptoms suggesting infection, blood in the urine or other urinary abnormalities.

5. Measurement of residual urine

A bladder ultrasound can measure the amount of urine left after voiding. This is particularly useful if there are symptoms suggesting incomplete bladder emptying or voiding dysfunction.

Do I need urodynamic studies?

This is one of the most common questions asked by women considering treatment.

Not every woman with straightforward stress urinary incontinence requires urodynamics.

Urodynamic testing measures how the bladder, urethra and pelvic floor behave while the bladder fills and empties. It can determine whether leakage is associated with increased abdominal pressure, whether involuntary bladder contractions occur and whether there is evidence of obstruction or impaired bladder emptying.

Contemporary guidelines generally do not recommend routine urodynamics before surgery in women with uncomplicated, clinically demonstrable SUI because it has not been shown to improve surgical outcomes.

Urodynamics becomes particularly useful when:

• The diagnosis is uncertain
• There are significant urgency or other storage symptoms
• Mixed urinary incontinence is present
• Voiding dysfunction is suspected
• There is significant pelvic organ prolapse
• Previous continence surgery has failed
• The symptoms and examination findings do not match
• There is suspected intrinsic sphincter deficiency
• The results may change the choice of treatment

In these situations, urodynamics can turn a clinical puzzle into a much clearer picture.

Treatment of stress urinary incontinence

Treatment is usually progressive, beginning with conservative measures and moving towards minimally invasive or surgical treatment when necessary.

The appropriate treatment depends on the severity of the leakage and, importantly, how much it bothers you.

1. Pelvic floor muscle training

Pelvic floor muscle training (PFMT) is generally the first-line treatment for SUI.

The pelvic floor muscles provide support to the bladder neck and urethra. Strengthening and correctly coordinating these muscles can significantly reduce leakage.

A structured program with a pelvic floor physiotherapist is preferable to simply being told to “do your Kegels”.

A good program may include:

• Identification of the correct muscles
• Strength training
• Endurance training
• Rapid contractions for coughs and sneezes
• Coordination of the pelvic floor with movement
• Techniques for managing leakage during exercise

Guidelines recommend supervised pelvic floor muscle training for at least three months as initial therapy for SUI.

The advantage is obvious: there is no incision, no anaesthetic and essentially no procedural risk.

The disadvantage is that it requires commitment, correct technique and time.

2. Lifestyle measures

Lifestyle modifications can make a meaningful difference, particularly when combined with pelvic floor rehabilitation.

These may include:

• Weight reduction where appropriate
• Optimizing fluid intake
• Reducing excessive caffeine intake
• Treating constipation
• Addressing chronic coughing
• Smoking cessation
• Modifying high-impact exercise temporarily while rehabilitation is undertaken

These measures rarely “cure” significant anatomical SUI on their own, but they can reduce symptoms and improve the results of other treatments.

3. Continence pessary

A vaginal continence pessary can provide mechanical support to the urethra and bladder neck.

It may be particularly useful for women who:

• Want to avoid surgery
• Have leakage predominantly during exercise
• Are awaiting surgery
• Have coexisting pelvic organ prolapse
• Want an additional treatment alongside pelvic floor rehabilitation

A pessary is fitted inside the vagina and can sometimes be removed and inserted by the patient.

Possible problems include vaginal irritation, discharge, discomfort and difficulty with insertion or removal. Regular review is important.

4. Vaginal oestrogen

For postmenopausal women with vaginal or genitourinary symptoms, local vaginal oestrogen may improve vaginal tissue health and urinary symptoms.

It is not a replacement for continence surgery when significant anatomical SUI is present, but it can be a useful component of treatment in appropriately selected women.

5. Urethral bulking injections

Urethral bulking involves injecting a material around the urethra to improve its ability to remain closed.

One example used clinically is polyacrylamide hydrogel.

The procedure is minimally invasive and can be attractive to women who:

• Prefer to avoid sling surgery
• Are poor surgical candidates
• Have recurrent SUI after previous surgery
• Want a relatively quick procedure

The trade-off is durability.

Bulking agents are generally less effective than sling procedures and repeat injections may be necessary. Their effectiveness can diminish with time.

Potential side effects include:

• Temporary urinary urgency
• Urinary tract infection
• Difficulty emptying the bladder
• Blood in the urine
• Discomfort
• Recurrent leakage
• Need for repeat treatment

6. Mid-urethral sling

For women with bothersome SUI who have not obtained sufficient improvement from conservative treatment, a mid-urethral sling (MUS) is one of the most established surgical treatments.

The sling sits beneath the middle portion of the urethra and provides support when abdominal pressure rises.

Two principal approaches have been used:

Retropubic mid-urethral sling

The tape passes behind the pubic bone.

Mid-urethral slings have substantially reduced the morbidity and complexity of traditional continence surgery, with high rates of improvement and continence. Contemporary evidence suggests broadly similar effectiveness between retropubic and transobturator approaches, although their complication profiles differ.

Importantly, mid-urethral sling surgery is not the same as the transvaginal mesh products that were used for pelvic organ prolapse. The Australian regulatory position is different. Mid-urethral slings for SUI remain approved products in Australia, with approved devices subject to Class III medical-device requirements.

What are the risks of a mid-urethral sling?

Although most women do well, sling surgery is not risk-free.

Potential complications include:

• Bleeding or haematoma
• Infection
• Bladder or urethral injury during insertion
• Temporary or persistent difficulty passing urine
• Urinary retention
• New or worsening urgency
• Recurrent stress incontinence
• Pelvic, groin or suprapubic pain
• Pain during sexual intercourse
• Mesh exposure or erosion
• Rarely, chronic pain or other mesh-related complications
• Need for further surgery

The TGA specifically identifies complications including bladder or urethral injury, mesh exposure or erosion, voiding dysfunction, urinary retention, urgency and acute or chronic pain among the potential adverse outcomes associated with urogynaecological mesh.

The decision to use a sling should therefore involve an individual discussion about benefits, alternatives and risks rather than treating the operation as a one-size-fits-all solution.

7. Autologous fascial sling

For women who wish to avoid synthetic mesh, another established surgical option is an autologous fascial sling.

A strip of the woman’s own tissue, usually rectus fascia from the lower abdominal wall, is fashioned into a sling and placed beneath the bladder neck/urethra.

This avoids a synthetic implant.

It can be particularly useful in selected women with:

• Severe stress incontinence
• Intrinsic sphincter deficiency
• Previous failed sling surgery
• Previous mesh complications
• A strong preference to avoid synthetic mesh

The disadvantages are that it is generally a more extensive operation, requires harvesting tissue and can have a higher risk of postoperative voiding dysfunction. Fascial harvest can also cause abdominal wound pain, infection, seroma or, rarely, hernia.

What about an allograft mid-urethral sling?

This is an important distinction.

An allograft is tissue obtained from another human donor, rather than tissue harvested from the woman herself. Historically, cadaveric fascia lata has been used to construct pubovaginal slings.

The attraction is obvious: it avoids harvesting the woman’s own rectus fascia and therefore avoids the additional abdominal wound associated with an autologous sling.

However, there is an important catch.

The evidence for allograft slings is considerably weaker than for modern mid-urethral synthetic slings or autologous fascial slings. This based on older studies and different mechanisms to prepare the graft.

Older studies of cadaveric fascia lata reported encouraging short-term outcomes, including reduced postoperative pain compared with harvesting autologous fascia. However, other studies reported substantial recurrence of stress incontinence, raising concerns about long-term durability.

Systematic evidence reviews have also concluded that the evidence supporting biological/allograft slings is limited and of low or very low certainty. In comparisons with synthetic slings, there has not been convincing evidence that cadaveric fascia lata provides a superior outcome.

For this reason, an allograft sling should not simply be regarded as a “mesh sling without mesh.”

Its role is much more selective.

Where available, it may be considered in carefully selected women who want to avoid synthetic mesh and would otherwise be candidates for a fascial sling, but the surgeon should explain the limitations of the evidence and uncertainty around long-term durability.

In Australia, the availability and regulatory status of any particular allograft product or technique should be confirmed with the treating surgeon and relevant institution. The TGA’s current approved urogynaecological mesh list specifically identifies approved devices for SUI, while not all historical mesh or biological products remain available.

8. Burch colposuspension

Burch colposuspension is a traditional operation in which sutures are placed to support the tissues around the bladder neck and urethra.

It can be performed through an abdominal approach, including laparoscopically or robotically in appropriately experienced centres.

It remains an important non-mesh surgical option, although it is more invasive than a mid-urethral sling.

Potential complications include:

• Bleeding
• Infection
• Bladder injury
• Postoperative urinary retention or voiding dysfunction
• New urgency
• Recurrent SUI
• Pelvic or abdominal pain
• Development or worsening of pelvic organ prolapse

Choosing the right operation

There is no single “best” operation for every woman.

The decision should take into account:

Consideration	Why it matters
Severity of SUI	Determines how much treatment is justified
Previous surgery	May alter the choice of procedure
Intrinsic sphincter deficiency	May favour a different surgical approach
Pelvic organ prolapse	May require combined treatment
Urgency/mixed incontinence	May affect expected outcome
Desire to avoid synthetic mesh	Makes fascial procedures more relevant
Previous mesh complications	May favour non-mesh options
General health	Influences operative risk
Future pregnancies	May influence timing and choice of surgery
Patient preference	An essential part of shared decision-making

The aim is not simply to make the pad dry. The aim is to find the treatment that gives the woman the best balance between continence, bladder function, quality of life and procedural risk.

What happens after treatment?

Following continence surgery, women are generally reviewed to assess:

• Continence
• Urgency and frequency
• Bladder emptying
• Residual urine
• Pelvic pain
• Sexual function
• Vaginal healing
• Mesh exposure where a mesh sling has been used

If symptoms persist or recur, further investigation may be necessary. In women with failed previous SUI surgery, repeat urodynamics and specialist assessment can be particularly valuable.

Australia also has the Australasian Pelvic Floor Procedures Registry, which collects information about stress incontinence and pelvic floor procedures with the goal of improving quality and long-term safety.

The bottom line

Stress urinary incontinence is common, but it is not something women simply have to put up with.

Treatment ranges from pelvic floor physiotherapy and lifestyle modification through to pessaries, urethral bulking injections and surgery.

For women requiring surgery, options in Australia include mid-urethral sling procedures, autologous fascial sling surgery and colposuspension, with the appropriate choice depending on individual circumstances.

An allograft fascial sling is a more specialised option. Although it avoids harvesting the patient’s own fascia, the evidence base is considerably less robust than that for established mid-urethral sling and autologous fascial sling procedures. It should therefore be discussed as a selective option rather than assumed to be a routine alternative to synthetic mesh.

Most importantly, treatment should be individualised. A woman should understand not only the likelihood of becoming dry, but also the possibility of urgency, voiding problems, pain, recurrent incontinence and other procedure-specific complications before making a decision.

If urinary leakage is interfering with exercise, work, relationships or everyday life, an assessment by a GP, urogynaecologist, urologist or pelvic-floor physiotherapist is a good place to start.

This information is intended for education and does not replace an individual medical assessment. Treatment availability, device approvals and clinical recommendations can change, so patients should discuss the current options with their treating clinician.

Don’t suffer in silence. Come see what your Brisbane Urologist Uro-Jo can do for you.