Thirty million men all over the world have symptoms related to BPO (Benign Prostatic Obstruction), with prevalence rising alongside age. The invasive urodynamic investigation (iUDS), e.g. a cystometry followed by a pressure/flow study, is the only test capable of providing detailed information regarding the function of the lower urinary tract and correlate it to LUTS. The role of invasive urodynamics (iUDS) before surgery for benign prostatic obstruction (BPO) is debated about the value and benefit it could give to the treatment. It is currently recommended only in selected cases prior to invasive treatment: 1) previous unsuccessful (invasive) treatment for LUTS, 2) in men who cannot void > 150 mL, 3) in case of post – voiding residue (PVR) > 300 mL, 4) in men with predominantly voiding LUTS and Qmax > 10 mL/s, 5) in patients with voiding LUTS aged > 80 years, 6) in patients with voiding LUTS aged < 50 years[1]. The UPSTREAM trial was a non-inferiority randomized controlled trial that investigated whether urodynamics would reduce the rates of surgical treatment without increasing urinary symptoms[2]. The included patients were men with bothersome LUTS for whom surgery was an option. Recent data coming from the same patients show that patients could be divided in two categories according to some parameters. Favourable parameters were age <74 years, Qmax < 10 mL/sec, ICIQ MLUTS >8, IPSS >16 and IPSS QoL >4, BOOI of>48 and/or BCI of >123.0[2]. The aim of this retrospective study was to find how many patients with iUDS were investigated in a single centre before possible surgery for BPO presented with favourable characteristics in order to avoid inappropriate surgery treatments.

This is a retrospective study based on one centre in the last 12 years, including consecutive male patients affected by lower urinary tract symptoms (LUTS) who were eligible for surgery for BPO. Patients with neurologic diseases, with previous lower urinary tract surgery, with incomplete data, or with patients outside general criteria were excluded. Criteria include age, IPSS score (including QoL), uroflowmetry, and iUDS data, with particular regard to the Bladder Outlet Obstruction Index (BOOI) and Bladder Contractility Index (BCI). All patients were divided into two groups (1): favourable outcome (IPSS>16, IPSS QoL>4, Qmax<10 mL/sec, age< 74 years old), and unfavourable outcome (presenting at least one of the unfavourable parameters). BOOI and BCI were evaluated in the patients with an unfavourable outcome, assuming, respectively, a cut-off of 48 and 123 above which outcomes after surgery should be favourable (2); the traditional cut-offs of 40 and 100, respectively, were also considered.

257 patients were included in this study. Mean age was 59.9 (IQR 14) years. Two hundred - nine (81.3%) patients showed affected storage and 204 (79.4%) voiding LUTS. Urgency was present in 125 (48.6%) cases, nocturia in 71 (27.6%) and terminal dribbling in 134 (52.1%), respectively. Mean BOOI and BCI were 55.7 (IQR 36.3) and 102.7 (IQR 45.9), respectively. Mean BVE was 71.9% (IQR 43).
Mean IPSS and IPSS QoL were 20.5 (IQR 4) and 4.5 (IQR 1). Mean peak flow rate was 8.2 (IQR 3.3) mL/sec, post voiding residue (PVR) was 141.9 (IQR 165). 92 patients (35.8%) were included in the “favourable outcome” group, whilst 165 (64.2%) had at least one unfavourable criterion. One hundred-eight (65.0%) patients showed only one criterion, 46 (27.9%) showed two, and 11 (6.7%) showed three criteria related to an unfavourable outcome (Figure 1). In the group with “unfavourable outcome”, 122 patients (73.9%) showed a BCI<123 (124 patients -75.2%- showed a BCI<100); 78 patients (48.9%) showed a BOOI<48 (88 patients -53.3%- showed a BOOI<40); 71 patients (43.0%) showed both a BCI<123 and a BOOI<48 (74 – 44.8%- both a BCI<100 and a BOOI<40). On the other hand, only 33 on these 165 patients (20.0%) showed both a BOOI >48 and a BCI >123.

This retrospective study of consecutive male patients investigated with iUDS prior to possible surgery for BPO showed a very high prevalence of patients presenting one or more parameters related to unfavourable outcomes according to UPSTREAM Trial[2], [3]. The study identifies some favourable conditions that predict the success of surgery such as ICIQ subscale score >8, IPSS score >16, ICIQ score >18, Qmax >9.8 ml/s, IPSS QoL >4 and age <74 years (fewer comorbidities) at baseline assessment. Patients without one or more of these parameters may have poor quality outcomes after surgery. According to our data, these parameters would identify only a minority of patients who would benefit post-obstruction with reduction of voiding LUTS. In the remaining patients the iUDS seem to provide possibly useful information, considering that 73.9-75.2% show detrusor hypoactivity, 48.9-53.3% show absence or mild obstruction and 43.0-44.8% both urodynamic findings, correlated with a worse postoperative outcome with little or, in some cases, no improvement in voiding LUTS. In this way iUDS could change the evaluation and subsequent treatment in men with LUTS avoiding unnecessary surgical interventions.

According to our findings, patients with parameters suggesting a favourable outcome after surgery for BPO seem to be a minority (35.8%). In the remaining patients, iUDS seem to provide possibly useful information. These data, together with the data coming from the UPSTREAM trials, may be used to identify patients for whom iUDS could help healthcare providers to better tailor the treatment.

J.N. Cornu et al., “European Urology Association (EAU) Guidelines on Non-Neurogenic Male Lower Urinary Tract Symptoms (LUTS), incl. Benign Prostatic Obstruction (BPO),” 2023.
G. J. Young 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, vol. 8, no. 5, pp. 1331–1339, Sep. 2022, doi: 10.1016/j.euf.2021.11.010.
G. J. Young 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, vol. 8, no. 5, pp. 1331–1339, Sep. 2022, doi: 10.1016/j.euf.2021.11.010.

Continence 12S (2024) 101405
DOI: 10.1016/j.cont.2024.101405