Recommendations for research
2.3.9 Endoscopy of the lower urinary tract
Endoscopy of the lower urinary tract provides information regarding comorbidities of the urinary bladder and urethra, which can be responsible for LUTS or may change the management of patients with prostate disorders. Endoscopy provides an estimation of prostate size by evaluating prostate length and the morphology of the prostate and bladder neck. However, bladder endoscopy (cystos-copy) has a low prognostic value for the diagnosis of BOO.
No new evidence regarding the utility of cystoscopy in men with LUTS has emerged since the 2006 Consultation, and so it is still not a recommended option in the initial assessment of men with uncomplicated LUTS (who constitute the majority of men with LUTS). The indications for cystos-copy in men include symptoms such as hematuria and recurrent UTI (216–217).
Recommendation
Do not use routine cystoscopy as part of the initial assessment in men who present with LUTS (Level 3, Grade C).
2.4 Urodynamics
2.4.1 Introduction
Urodynamics is the term used to describe testing and measurements of the function of the lower urinary tract. It allows for assessment of the two essential functions of the lower urinary tract: the storage of urine at low pressure and the voluntary evacuation of urine. Low-pressure storage is essen-tial to protect kidneys and assure continence, while voluntary evacuation allows for the elimination of urine in socially acceptable situations without fear of leakage or over-distension. When one or both of these functions are disrupted, the result often manifests as symptoms bothersome to the affected individual. These LUTS have been well categorized earlier in this chapter.
In some cases, a precise assessment of storage and emptying is helpful or even necessary to optimally treat patients. Urodynamics includes the actual tests that are performed (urodynamic studies) and the observations made during the testing (urodynamic observations) (4,218). Although UDS consists of a number of tests that can individually or in combination assess lower urinary tract function (uroflow, cystometry, abdominal pressure [Pabd] monitoring, and electromyography of the urethral sphincter), the term urodynamic study generally implies that a cystometrogram is performed (with or without other tests) to measure bladder pressure during filling and voiding.
In this section, we will discuss the use of UDS in the assessment and treatment of LUTS in men.
There are several urodynamic findings as defined by the ICS (4) that are commonly associated with LUTS:
Bladder outlet obstruction: A urodynami-cally diagnosed condition characterized by increased Pdet and decreased urine flow during voiding
Detrusor overactivity: A urodynamic obser-vation characterized by IDCs during the filling phase, which may be spontaneous or provoked; DO may be phasic or terminal (a single involuntary contraction at cystomet-ric capacity)
Detrusor underactivity: A detrusor contrac-tion of reduced strength and/or duracontrac-tion, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span
Impaired compliance: An impaired relation-ship between change in bladder volume and change in Pdet, which occurs when pressure increases significantly with increasing volume in the absence of a detrusor contraction
Bladder outlet obstruction and detrusor underactivity are diagnosed during the voiding phase of UDS, while DO and impaired contractility are diagnosed during the filling phase. Many times, these conditions coexist. Detrusor underactivity can be a consequence of long-term BOO, as the bladder decompensates for increased retention of urine and constant high-pressure contraction against an obstructed outlet. It can be challenging to diagnose BOO in the presence of detrusor underactivity, as high-pressure low flow is required for the diagnosis. Finally, impaired compliance, though rela-tively rare, can be a long-term sequela of BOO. In the absence of obstruction, impaired compliance can occur secondary to structural changes in the bladder due to conditions like radiation cystitis and tuberculosis.
Over the past decade, there has been some evolution of views about the urodynamic evaluation of LUTS in men with possible BPO. Men in middle or older age present with LUTS that may be, but are not necessarily, related to prostatic changes such as benign or malignant enlargement and obstruction. Lower urinary tract symptoms may be due to dysfunction anywhere in the complicated mechanical and neural control system that allows normal lower urinary tract function.
It has previously been stated that the aim of UDS should be to reproduce specific LUTS while taking measurements that will reveal their cause. However, because the number of possible causes is quite large, it is often useful to go beyond the mere reproduction of the symptom and to document the complete function of the lower urinary tract during both filling and voiding phases. For example, if cystometry is performed to ascertain the cause of incontinence, and if incontinence is indeed demonstrated during the filling phase, it is still wise to complete filling and examine the voiding phase because unsuspected abnormalities may contribute to the incontinence. As well, testing may reveal urethral obstruction, poor voiding, elevated residual urine, or possible neuropathy, which may change the interpretation of the symptoms, alter the presumed diagnosis, or change the choice of treatment. Thus, when one commits to performing UDS, an attempt should be made to correlate an abnormality with the symptoms, but also to perform a complete evaluation of lower urinary tract storage and emptying functions to possibly uncover other irregularities that may be associated with the patient’s symptoms or may represent a treatment target. The results of UDS represent just one aspect of the assessment of male LUTS (with other aspects including symptoms and anatomical abnormalities). Adhering to this view means that it is not necessary in all cases to reproduce the symptoms during UDS. However, performing complete UDS is still warranted.
With a multitude of possible underlying causes of LUTS in men, one obvious question is how neces-sary is it to make a specific UDS diagnosis of the cause(s) and LUTS before instituting treatment (or observation)? In some cases, the answer is that UDS is not necessary. However, there are specific instances where UDS is very helpful, depending on specific patient characteristics, response to prior treatment, planned treatment, etc. The role of UDS in clinical practice has been nicely summarized by Hosker et al. (219), and this role certainly extends to the evaluation of men with LUTS.
Urodynamics may be used to:
1. Identify or rule out factors contributing to LUTD (e.g. UI) and assess their relative importance
2. Obtain information about other aspects of lower urinary tract function or dysfunction
3. Predict the consequences of LUTD on the upper urinary tract
4. Predict the outcome, including undesirable side effects, of a contemplated treatment
5. Confirm the effects of intervention or under-stand the mode of action of a particular type of treatment (especially a new one)
6. Understand the reasons for failure of previ-ous treatments for symptoms (e.g. UI) or for lower urinary tract function in general
Ultimately, the main aim of UDS in clinical practice is to guide therapy and improve outcomes.
Its ability to do this must be judged based on the evidence provided by trials and cohort studies.
Urodynamics is also very important as a research tool, where the main aim is to gather knowledge about the diseases encountered and how best to treat them (i.e. to ensure that medical practice is knowledge-based).
When a condition is first widely encountered, there is a phase in which clinical research is crucial to generate new knowledge. Once etiology has been established, the debate can shift to whether routine clinical UDS is necessary for a specific condition (e.g. Should UDS be limited to selected difficult cases or performed more widely?). Because UDS remains the only way of objectively establishing the pathophysiological situation, urodynamic evaluation always remains necessary in at least the difficult cases.
Since the previous International Consultation (3), there has been some evolution of views about the urodynamic evaluation of LUTS in men with and without possible BPO. In the present report, these views are updated bearing in mind the historical perspective and focusing on publications from 2005 onward. We once again cover the topic of UDS investigation of LUTS in prostate cancer and its treat-ment, updating the literature since the previous Consultation in 2005 (3).