1. Urodynamic studies in women with POP and UI
Francesco Cappellano, MD, FEBU
Head of Urology and Neurourology Clinic
Pelvic Care Centre
Harley Street Hospital – Abu Dhabi ( UAE)

2. Why urodynamics…?
Urodynamics are a means of evaluating the pressure-flow relationship between the bladder and the urethra for defining the functional status of LUT
The goal is to aid in the correct diagnosis of LUTD based upon its pathophysiology.
Assess both the filling and storage phase, as well as the voiding phase of bladder and urethral function.
In addition, provocative tests can be added to try to recreate symptoms and assess pertinent characteristics of urinary leakage

3. Urodynamics
Selection of patients for complex urodynamic testing can be difficult.
The criteria that do exist are rooted more in expert opinion than in evidence-based scientific findings.
In general, urodynamic testing is pursued with a diagnostic question in mind or, at times, to obtain a baseline measure of bladder function
Therapeutic outcomes are tied to understanding the pathophysiology of a given case, and making the correct and complete diagnosis

4. The following historical factors suggest the need for complex testing.
Patient Selection
The following historical factors suggest the need for complex testing.
Unclear or complicated history
Significant urge component
History of urinary retention
Previous failed incontinence surgery
Continuous incontinence or leakage with minimal activity
Elderly patient (>65 y) with multiple possible diagnoses
Advanced diabetes
Nocturnal enuresis if other diagnostics are exhausted
Nulliparous woman with stress incontinence
Known or suspected neurologic disease

5. Physical exam
Physical examination findings that may prompt consideration of complex urodynamic evaluation
Abnormal central nervous system, lower extremity, or pelvic floor neurologic findings
High postvoid residual volume
Stress incontinence with minimally increased intra-abdominal pressure, with an empty bladder, or positive supine stress test
Abnormal simple cystometry

6. Strategy Components essential to planning surgical therapy:
Stress testing
Cystometry
Uroflowmetry
Postvoid residual urine volume determination
Abdominal (or Valsalva) leak point pressure

7. Video Urodynamics
Videourodynamic studies have become the investigative technique of choice for incontinence in many referral centers.
Simultaneous display of real-time images of the bladder neck and urethra, as well as bladder, intra-abdominal, and, in some cases, urethral pressures.

8. Advantages of video…
Precise placement of pressure transducers and a constant understanding of exact anatomic location.
Observe the bladder neck area throughout bladder filling and during stress maneuvers.
Contrast material can be observed entering the proximal urethra just before leakage
Is the most sophisticated diagnostic test for an incontinent patient

9. If I haven’t Video UD ?
In the absence of videourodynamics, the clinician may obtain adequate information from the following
Noninvasive uroflow and postvoid residual urine volume
Simple cystometry in combination with cystoscopy
Detailed speculum examination
Cough stress test and Q-tip test
Dynamic retrograde urethroscopy
Antegrade or retrograde cystourethrography is a useful tool when urinary tract fistulas or diverticulum are suspected

10. Testing protocol considerations
Basic technical points include the choice of fill medium, the infusion rates, and the types of catheters
A liquid medium, usually saline, is preferred.
Most testing is performed with room-temperature solutions
The filling rate can vary and usually ranges from mL per minute.
Slower, more physiologic rates can be used if a suspected false-positive result is obtained at faster rates

11. Catheters
Catheters generally should be 10 French or less in caliber to avoid urethral irritation and obstruction of flow.
Microtip or air-filled transducers are used most commonly in clinical practice
Patient position during testing varies, but most commonly, the patient is sitting, semi-erect, or standing

12. Filling phase
For clinical purposes, the emphasis often is on the filling-storage segment.
During filling, normally, detrusor pressure does not rise.
This finding reflects the compliance of the bladder

13. Filling phase
Initial small increase in intravesical pressure at the beginning of filling
Stable pressure that comprises the majority of the filling phase
Terminal pressure rise at bladder capacity, representing the limit of viscoelastic expansion
Voiding phase with an increase in intravesical pressure

14. Bladder sensation and capacity
The first sensation is the volume at which the patient first is aware of fluid in the bladder (reference range of mL).
The second sensation (full) is the volume at which the individual normally would consider voiding due to an urge sensation (reference range of mL).
Maximum capacity is when the patient is experiencing pain and does not allow continued filling (reference range of mL).
The average bladder holds mL of urine.

15. Overactive bladder

16. Neurogenic overactive bladder

17. Dyssynergia

18. Any bladder contraction during filling is considered abnormal, but the clinical significance of bladder contractions that are asymptomatic are uncertain.
The ICS has identified a minimal contraction amplitude of 15 cm H2O over baseline to be considered significant

19. Overactive bladder
Demonstration of urgency coincident with increase in true detrusor pressure defines detrusor overactivity

20. PVRU
High postvoid residual (PVR) urine volumes indicates bladder outlet obstruction or impaired contractility
High PVR urine volumes are uncommon in females.
Only 5% of asymptomatic females and 13% of  symptomatic females have PVR volumes greater than 30 mL.
 Some authorities consider volumes greater than mL to be abnormal.
Others use a value greater than 20% of the voided volume to indicate a high residual.

22. Uroflowmetry
Urine flow rates are a product of detrusor contraction strength, urethral resistance, and in some instances the contribution of abdominal straining.
Normal flow curves are bell shaped and display a rapid rise to peak flow, a short duration of peak flow, and a rapid fall

23. In females, the role of uroflowmetry is controversial.
Voiding dysfunction is uncommon, except in the patient who recently had incontinence surgery.
Females can complete successful voiding in a number of ways.
Using Valsalva augmentation of voiding is not uncommon.
Some females void by urethral relaxation alone.

24. Uroflow studies may be useful in predicting the risk for voiding dysfunction and high residual volumes after incontinence surgery.
Patients with low flow rates may be at risk for prolonged catheterization.
In one study, 38% of the patients with abnormal uroflow results before surgery required postoperative catheter drainage for more than 1 week.
Only 10% of those with normal study results required prolonged drainage

25. Valsalva LPP
Is a test of the urethral sphincter resistance against increases in intra-abdominal pressure
The lower the leak point pressure, the weaker the urethral sphincter and the more severe the stress incontinence
It is used to determine whether stress urinary incontinence results from urethral hypermobility, intrinsic sphincter deficiency, or both in combination
… and which surgical intervention may be best…

26. Intravesical and intrarectal catheters are placed and the bladder is filled with 150-250 mL of fluid
The patient is asked to perform a Valsalva maneuver of slowly building intensity.
The lowest pressure at which leakage is observed denotes the leak point pressure.

28. The presence of a transurethral bladder catheter may affect leak-point pressure significantly, compared with measurements obtained using a catheter for abdominal pressure only
Leak-point pressures are as much as 20 cm water lower without a transurethral catheter
Patient position is also thought to potentially affect leak point pressure. 

29. Leak-point pressures below 60 cm water are considered to define intrinsic sphincter deficiency
Others have cited 80 cm or 90 cm water as the threshold
It is important to note that a normal leak-point pressure should approach infinity.
Patients with a normal continence mechanism can generate intra-abdominal pressures high enough to cause fainting without provoking stress incontinence

30. UD and POP
POP along with urinary and fecal incontinence, voiding and defecatory dysfunction make up the inter-related group of disorders collectively known as the “Disorders of the Pelvic Floor”
Clinical decision making in the field of POP and/or UI surgery continues to be based on historical single-department experience or physician’s perception
Over the last decade, accurate preoperative evaluation of women with POP and/or UI and knowledge of patients’ expectations were developed

31. Instruments include risk groupings, lookup tables, classification and regression tree analyses, prediction models presented in the form of nomograms, and artificial neural networks (ANNs).
Serati et al. in 2011 used an advanced computer-based ANN technology to investigate the correlation between urinary symptoms and urodynamic assessment in women with POP.
They wanted to know whether ANN could supplement, or even replace, urodynamic assessment in the preoperative workup in women with POP.

32. The conclusion was that urodynamic evaluation is better
Decisions about POP repair surgery cannot be based on symptoms and signs alone.
Preoperative urodynamic assessment in women with POP aims at correlating observed or reported disease with a urodynamic finding or identifying subclinical disorders that could have an impact on the expected outcome
More than 800 patients

33. Invasive tests are not always indicated for healthy premenopausal women with
low stage POP and pure stress urinary incontinence (SUI)
urethral hypermobility, without storage, voiding or post micturitional symptoms
no urogynaecological surgery.

34. There are several challenges in managing women with POP and SUI
To identify intrinsic urethral sphincter that requires a concomitant anti-incontinence procedure
To disclose detrusor overactivity or underactivity,
To know what is the bladder compliance

35. In all previous cases urodynamic assessment might be considered mandatory
Transobturator slings are reported to be less effective in patients with intrinsic sphincter deficiency (ISD).
Identifying ISD might change the plan

36. In patients with or without concomitant incontinence, scheduled for POP repair, urodynamic assessment might allow a more selective use of incontinence surgery
Surgeons and their patients must weigh the risks and benefits of performing prophylactic procedures during POP surgery

37. Conclusion
The incidental discovery of detrusor overactivity in a healthy woman with straightforward POP or SUI would not change the surgical plan
Detrusor underactivity increases the risk for postoperative voiding dysfunction, and urodynamic assessment serves to identify patients at increased risk
Simple low-cost uroflowmetry might be used to discriminate candidates requiring invasive tests

38. Conclusion
Urodynamics is crucial when planning an integral pelvic floor reconstruction
Poor compliance could be worsened if outlet resistance is increased by a concomitant anti-incontinence procedure .
In such cases, identifying patients with low compliance is mandatory
So urodynamic assessment should be the ‘‘gold standard’’ before POP surgery.
So far we have gained some clues, but our course remains ‘in fieri’ ( ongoing ).

39. šukran