Invasive Urodynamics Before BPH Surgery: Routine Test or Selective Tool?

The July 2025 issue of European Urology Focus, edited by Silvia Sacco and Dean Elterman, contains a special section providing an extensive and detailed exploration of current topics in the management of benign prostatic hyperplasia (BPH), highlighting pivotal debates, various interventions, practical clinical guidance, and cutting-edge research insights. Two of the articles address the utility of invasive urodynamic studies (UDS) in patients whose symptoms suggest that etiology may be BPH. Clout et al.¹ reported a 5 year follow up study to the UPSTREAM trial.²

This was a study in which patients were randomized to a pathway that either included or excluded invasive urodynamic testing in the evaluation and management of men with lower urinary tract symptoms (LUTS). Reported findings after 18 months following randomization showed that UDS was not inferior to routine care (no UDS) for symptom severity based on the International Prostate Symptom Score (IPSS), and that inclusion of UDS in the pathway did not reduce the proportion of men opting to have interventional treatment.

The follow up study confirmed that the routine use of UDS does not improve symptom outcomes or reduce surgical rates when compared to standard diagnostic assessments alone. Both groups showed similar IPSS Scores and comparable surgical intervention rates over the five years of follow-up, reinforcing the conclusion that invasive UDS should be used very selectively rather than as a routine preoperative test in such patients. The authors further concluded that, while urodynamics offers additional physiological insights, its widespread use in patients with uncomplicated LUTS may not be cost effective or clinically necessary. 43 percent of men in each group received at least one LUTS operation during the five-year follow-up.

The statistics from the follow up study further eliminated the possibility that the conclusions from the original UPSTREAM report could have been affected by failure to deliver Interventions in the 18-month time frame. As the authors stated, “The conclusion remains that the routine use of UDS testing in uncomplicated LUTS has a limited role and should be used selectively. Enrico Finazzi Agro and associates, in a very thoughtful article in that same 2025 issue,³ pointed out that the UPSTREAM trial did in fact support the “selective” use of UDS in men prior to surgery for benign prostatic obstruction and asked the obvious question: exactly which patient groups were included under the term selective. They cited other evidence, drawn from the upstream trial data,⁴ which suggested that factors predicting successful BPO surgery, independently from UDS, were: patient 73 years or older, IPSS score greater than 16, predominantly in the voiding phase, meaning an ICIQ-MLUTS voiding sub scale score of greater than 8, with a significant impact on quality of life, meaning IPSS QOL of greater than 4.

Criteria predictive of a successful outcome also included an IT peak flow rate of less than 9.8 ml per second, and, for those who underwent invasive UDS, a Bladder Outlet Obstruction Index (BOOI) greater than 48, the exclusion of detrusor underactivity (which they did not further define), and a bladder contractility index (BOOI) of greater than 123. 

They also cited another study, this one from Japan I,⁵ which used a different cohort of data, confirming that the factors identified in UPSTREAM were associated with favorable outcomes after surgery, while the presence of voiding LUTS not affecting QOL, peak flow of 13 ml per second or greater, patients with symptoms of nocturia, incontinence, or post void dribbling, and those with extensive comorbidity were associated with poorer outcomes. They cited other studies done preoperatively, showing that detrusor underactivity was related to poorer improvements in IPSS and peak flow⁶ and, although detrusor over activity (DO) will resolve after BPO Surgery in 60 to 80% of patients, worse outcomes were associated with a lack of obstruction, terminal DO, low maximum cystometric capacity and early and high amplitude DO,⁷ suggesting that if DO was suspected, invasive UDS may be relevant for patient counseling and a better treatment choice.

It is hard to argue with the conclusions drawn by Finazzi Agro et al., basically from the EAU guidelines on management of non-neurogenic male LUTS, regarding situations for which invasive UDS may prove particularly valuable:        

1. Men who have had previous unsuccessful invasive treatment for LUTS before further invasive treatment
2. Men considering invasive treatment who cannot void greater than 150 ml
3. Men with bothersome predominantly voiding LUTS and peak flow greater than 10 ml/sec for whom surgery is being considered
4. Men with bothersome predominantly voiding LUTS with a post void residual volume of greater than 300 ml who are considering invasive therapy
5. Men with bothersome predominantly voiding LUTS aged greater than 80 or less than 50 years who are considering invasive treatment.

They also add the following categories of patients in whom they feel invasive UDS may be useful: those with mixed symptomatology (with higher bother from filling phase LUTS) and suspected detrusor underactivity, and patients with comorbidities for whom a benign prostatic obstruction diagnosis may be mandatory before surgery.

And so, the two articles,^1,3 while they may at first seem to be on opposite sides of the field, are not so far apart in their final conclusions. Debate will continue as to the “proper” use of invasive UDS in the evaluation of men with LUTS. An upcoming article in European Urology Focus illustrates this nicely.⁸ This is a report of an international expert consensus project, the purpose of which, was to clarify the appropriate use of UDS in men with bothersome LUTS who were considering prostate surgery, in the light of high quality published evidence, particularly high certainty data from the UPSTREAM study, and expert clinical experience A modified version of the Delphi method was employed in which consensus was solicited on the need for UDS in a number of different scenarios. The panel consisted of 20 experts in functional urology collectively representing twelve countries across Europe and North America. Articles which were considered to contain high quality evidence and reviewed before opinion capture are listed in the bibliography of this article. The article is worth reading in its entirety. You will see, from the listing of the consensus percentages achieved for each of 12 critical questions, that agreement, although quite high for some questions, was hardly unanimous:

1. UDS should be done if the corrected maximum flow is 13 ml/sec or greater: 75% consensus
2. UDS should be done if bothersome urinary urgency is observed on the symptom score or bladder diary: 71%
3. UDS should be done if the total symptom score is below a specific threshold ( less than 17 IPSS, less than 19 ICIQ-MLUTS): 71%
4. UDS should be done if the voiding symptoms subscale is low((ICIQ-MLUTS 8 or less): 71%
5. UDS should be done if the impact of symptoms on quality of life is low(IPSS 4 or less): 52%
6. UDS should be done if the post void residual volume is meaningfully elevated in the opinion of the investigator (volume or efficiency not further specified): 76 %
7. UDS should be done if there is extensive comorbidity in the opinion of the investigator: 74%
8. UDS should be done if incontinence is observed on the symptom score or bladder diary:80%
9. BOOI and BCI should be validated by cross checking the timing of the corrected maximum flow within the urodynamic pressure traces and by visual validation of detrusor, vesical, and abdominal pressures:90%
10. Presence or absence of detrusor I overactivity should be validated by evaluating vesical and abdominal pressure during filling cystometry:88%
11. To ensure reliability of the traces UDS should always be performed by, or the traces reviewed by, a healthcare professional with expertise in good urodynamic practice before confirmation of the urodynamic diagnosis:82%
12. The UDS diagnosis should always be considered in its clinical context:71%

The debate will go on!

Written by: Alan Wein, MD, PhD, FACS, Professor of Clinical Urology, Department of Urology, Desai Sethi Urology Institute (DSUI), University of Miami Miller School of Medicine, University of Miami Health Systems, Miami, FL

References:

1. Clout, M et al. Five -year follow up of the Urodynamics for prostate surgery trial; randomized evaluation of assessment methods - a non inferiority randomized control of urodynamics. Eur Urol Focus, 2025; 11: 618-624
2. Drake, M et al. Diagnostic Assessment of lower urinary tract symptoms in men considering prostate surgery: a non-inferiority randomized control trial of urodynamics in 26 hospitals. Eur Urol, 2020; 78:101-110
3. Finazzi Agro, E et al. What is the role of invasive urodynamics in the assessment of male lower urinary tract symptoms/ benign prostatic hyperplasia. Eur Urol Focus, 2025; 11: 575-578
4. Young, G et al. Prostate surgery for men with lower urinary tract symptoms: do we need urodynamics to find the right candidates? Exploratory findings from the UPSTREAM trial. Eur Urol Focus, 2022; 8: 1331-1339
5. Ito, H et al. Predicting prostate surgery outcome from standard clinical assessments of lower urinary tract symptoms to derive prognostic symptom and flowmetry criteria. Eur Urol Focus, 2023; 10: 197-204
6. Kim,M. Effect of preoperative urodynamic detrusor under activity on transurethral surgery for benign prostatic hyperplasia: a systematic review and meta-analysis. J Urol, 2018; 199:237-244
7. Creta, M et al. Detrusor overactivity and under activity: implication for lower urinary tract symptoms related to benign prostatic hyperplasia diagnosis and treatment. Minerva Urol Nephrol, 2021; 59-71
8. Drake, M et al. The evidence-based role of urodynamics in men with lower urinary tract symptoms considering prostatic surgery: an international expert consensus. Eur Urol Focus, https://doi.org/10.1016/j.euf.2025.12.018