ROLE OF THE PREOPERATIVE POST VOID RESIDUAL URINE VOLUME IN MALES UNDERWENT TRANSURETHRAL RESECTION OF THE PROSTATE FOR LOWER URINARY TRACT SYMPTOMS

Rubilotta E1, Trabacchin N1, Soldano A1, Bassi S1, Balzarro M1

Research Type

Clinical

Abstract Category

Male Lower Urinary Tract Symptoms (LUTS) / Voiding Dysfunction

Abstract 293
E-Poster 2
Scientific Open Discussion ePoster Session 18
Thursday 5th September 2019
13:20 - 13:25 (ePoster Station 1)
Exhibition Hall
Male Voiding Dysfunction Surgery
1.Dept. Urology AOVR Verona Italy
Presenter
E

Emanuele Rubilotta

Links

Poster

Abstract

Hypothesis / aims of study
Post-void residual (PVR) of urine is a common part of the routine clinical assessment in males with lower urinary tract symptoms (LUTS) (1). Post-void residual of urine can be measured by transabdominal ultrasound (US), bladder scan (BS) or catheterisation. A missing established PVR threshold for treatment decision is the main limit of this parameter, due to large test-retest variability and lack of outcome studies. Moreover, the diagnostic accuracy of PVR is low. The use of a PVR threshold of 50 mL has a positive predictive value (PPV) of 63% and a negative predictive value (NPV) of 52% as a predictor of bladder outlet obstruction (BOO)(2). The identification of at risk patients for acute urinary retention (AUR) may be achieved monitoring the changes over time of PVR measurements(3). Furthermore, in patients with lower urinary tract symptoms, high baseline PVR is associated with an increased risk of symptom progression 
Aim of this study was to assess the role and the values of the preoperative PVR in males underwent transurethral resection of the prostate (TURP) for LUTS and the related outcomes after the procedure.
Study design, materials and methods
This is a prospective ongoing study started in January 2017 involving males with LUTS candidates for TURP. The medical and urological history was recorded in all the population. Both preoperative evaluation and the 1-year follow-up consisted in: peak flow (Qmax), PVR, PVR-ratio as the ratio of PVR to bladder volume (BV: voided volume + PVR), and the International Prostate Symptoms Score Questionnaire (IPSS). Patients were also distributed in groups according to preoperative PVR thresholds: i) PVR 0-50ml; ii) PVR 51-100ml; iii) PVR 101-150ml; iiii) PVR 151-200ml; iiiii) PVR>200ml. Statistical analysis was performed using T-test, Wilcoxon test, one-way ANOVA test, Kruskal-Wallis Test.
Results
Data were complete in 52 patients, with a mean age of 68.9+8.5 yrs. A significant improvement in voided volume, Qmax, PVR, IPSS score was documented. Mean voided volume was 214.8 ml (sd 102.1 ml) and 301.0 ml (sd 335.9 ml) respectively preoperative and postoperative. Mean Qmax was 9.7 ml/s (sd 4.2 ml/s) and 19.5 ml/s (sd 10.2 ml/s) respectively preoperative and postoperative. Mean post-void residual of urine was 120.5 ml (sd 125.9 ml) and 25.8 ml (sd 25.4 ml) respectively preoperative and postoperative. Mean preoperative PVR ratio was 31.1% (ds 22.3%) ml) and 9% (ds 8.8%) postoperative. Mean preoperative IPSS scores was 22.6 (sd 7) and 8.7 (sd 6) postoperative. The majority of the males showed a PVR < 100ml (59.6%), while the remaining 21/52 patients (40.4%) had a PVR >100ml. No significant difference was found in Qmax and IPSS score among the groups, in both preoperative and postoperative assessment (Table 1). In each group we found a significant improvement in Qmax and IPSS score after transurethral resection of the prostate (Tables 2). Table 2 shows also how post-void residual of urine decreased significantly after TURP in all the groups except in the Group i (PVR 0-50ml). This finding may be related to the low preoperative post-void residual of urine.
Interpretation of results
Only a minor part of the males showed a high preoperative post-void residual of urine (>100ml), therefore PVR did not have a crucial role in the decision-making. Quite the reverse, Qmax and symptoms score had the main influence. Post-void residual of urine was not correlated to preoperative and postoperative Qmax and IPSS. This finding suggests that post-void residual of urine was a poor predictive factor for the decision-making and outcomes in males candidates for transurethral resection of the prostate.
Concluding message
In our cohort a high post-void residual of urine was present only in a minority of patients candidates for transurethral resection of the prostate and did not significantly influence the outcomes of TURP. This study confirmed that post-void residual of urine is still a controversial and poor reliable parameter in the evaluation of males with lower urinary tract symptoms. as well in the treatments’ decision-making.
Figure 1
Figure 2
References
  1. Abrams P. New words for old: lower urinary tract symptoms for "prostatism". BMJ. 1994;308:929-930
  2. Oelke M. Hofner K, jonas U, de la Rosette JJ, Ubbink DT, Wijkstra H. Diagnostic accuracy of noninvasive tests to evaluate bladder outlet obstruction in men: detrusor wall thickness, uroflowmetry, postvoid residual urine, and prostate volume. Eur Urol 2007 Sep;52(3):827-34
  3. Roehrborn CG. Alfuzosin 10 mg once daily prevents overall clinical progression of benign prostatic hyperplasia but not acute urinary retention: results of a 2-year placebo-controlled study. BJU 2006 Apr;97(4):734-41
Disclosures
<span class="text-strong">Funding</span> None <span class="text-strong">Clinical Trial</span> No <span class="text-strong">Subjects</span> Human <span class="text-strong">Ethics not Req'd</span> Approval not required by our internal ethical commuttee <span class="text-strong">Helsinki</span> Yes <span class="text-strong">Informed Consent</span> Yes