INTRODUCTION AND AIM OF THE STUDY: Detrusor Underactivity (DU) is deﬁned , according to ICS, as ‘‘a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or failure to achieve complete bladder emptying within a normal time span’’. It is a common urodynamic observation in patients (pts) presenting for evaluation of urinary incontinence and/or lower urinary tract symptoms (LUTS) following radical prostatectomy (RP) . In the literature its prevalence varied from 29% to 61%, and it was ‘‘de novo’’ in 47% of pts (1); according to other Authors, DU was even more frequent after RP (2). Detrusor denervation at surgery is a plausible explanation for DU, but many other factors may contribute to its occurrence. The aim of the study was to evaluate the prevalence of DU in pts who underwent RP and to correlate it with demographic, clinical and other urodynamic variables. MATERIALS AND METHODS: The urodynamic traces and reports of 77 consecutive pts were retrospectively evaluated. Studies on pts with artiﬁcial urinary sphincter (AUS) and duplicate studies on a single patient were excluded. The mean age of the pts studied was 69.73 years (range 57–81). The indications for urodynamics were mainly stress or mixed urinary incontinence, often associated with voiding symptoms. DU was deﬁned by Bladder Contractility Index (BCI ) < 100 or maximum Pdet < 20 cm H2O during attempted voiding (3). The following demographic and clinical parameters were correlated with DU: age at RP; BMI; comorbidity; type of procedure (retropubic, laparoscopic or robotic) ; nerve-sparing status; pathological stage and grade of the neoplasm; radiation after RP; interval between RP and urodynamics; LUTS such as stress urinary incontinence (SUI), mixed urinary incontinence (MUI), voiding LUTS. DU was then correlated with other urodynamic variables: urodynamic stress incontinence (USI); detrusor overactivity (DO) ; bladder compliance; maximum cystometric capacity; Bladder Outlet Obstruction Index (BOOI); post-void residual (PVR). Pts who voided with exclusive abdominal straining, in the absence of voluntary detrusor contraction, and pts unable to void in spite of a detrusor contraction (not adequately sustained), were excluded from the statistical analysis. Data were statistically analysed with median values and interquartile ranges for the continuous variables, and with Pearson’s chi-square test for the categorical variables. Statistical signiﬁcance was set at P < 0.05 . All data analyses were performed using SPSS release 12.0 for Windows. RESULTS : mean age at RP was 65.25 (range:54–78). BMI was on average 26.78 (range: 21.97–35.7). The type of RP, performed in different centres, was retropubic in 61 cases (79.2%), laparoscopic in 9 (11.68%) and robotic in 7 (9,09%). Post-operative radiation was performed in 21 pts (27.27%). The average interval between RP and urodynamics was 125.5 months (range: 7–120). As regards the clinical picture, the predominant symptoms were SUI and MUI, often associated with voiding LUTS. Statistical analysis was applicable on 64 pts. The only signiﬁcant correlation was found between DU and age >70 yrs (P = 0.033); abdominal voiding in 6 pts; no voiding and minimal/not sustained detrusor contraction in 2 pts. INTERPRETATION OF RESULTS: The present study conﬁrmed the high prevalence of the voiding dysfunction following RP. The most frequent urodynamic observation was USI, followed by DO, as expected: in fact, the population studied was selected and mostly included pts with urinary incontinence. Also, the prevalence of DU was high (64.9%), similar to that found by other Authors (2). Statistically, the only parameter signiﬁcantly correlated with DU was the advanced age ( >70 yrs). CONCLUSIONS: DU is an important part of the complex of lower urinary tract dysfunction occurring after radical prostatectomy. It needs to be well-studied in order to precise its real incidence and pathophysiology, still unclear. The clinical importance of this urodynamic observation in pts who underwent RP is important not only in pts with voiding problems and/or urinary retention, but also in incontinent pts who are potential candidates for sling placement.
|Titolo:||DETRUSOR UNDERACTIVITY AFTER RADICAL PROSTATECTOMY: A RETROSPECTIVE ANALYSIS|
|Data di pubblicazione:||2014|
|Appare nelle tipologie:||01.05 Abstract in rivista|