Factors determining the amount of residual urine in men with bladder outlet obstruction: Could it be a predictor for bladder contractility?

Abstract

ObjectiveTo determine from urodynamic data what causes an increased postvoid residual urine volume (PVR) in men with bladder outlet obstruction (BOO), urethral resistance or bladder failure, and to determine how to predict bladder contractility from the PVR.Patients and methodsWe analysed retrospectively the pressure-flow studies (PFS) of 90 men with BOO. Nine patients could not void and the remaining 81 were divided into three groups, i.e. A (30 men, PVR < 100 mL), B (30 men, PVR 100–450 mL) and C (21 men, PVR > 450 mL). The division was made according to a receiver operating characteristic curve, showing that using a threshold PVR of 450 mL had the best sensitivity and specificity for detecting the start of bladder failure.ResultsThe filling phase showed an increase in bladder capacity with the increase in PVR and a significantly lower incidence of detrusor overactivity in group C. The voiding phase showed a significant decrease in voided volume and maximum urinary flow rate (Qmax) as the PVR increased, while the urethral resistance factor (URF) increased from group A to B to C. The detrusor pressure at Qmax (PdetQmax) and opening pressure were significantly higher in group B, which had the highest bladder contractility index (BCI) and longest duration of contraction. Group C had the lowest BCI and the lowest PdetQmax.ConclusionsIn men with BOO, PVR results from increasing outlet resistance at the start and up to a PVR of 450 mL, where the bladder reaches its maximum compensation. At volumes of >450 mL, both the outlet resistance and bladder failure are working together, leading to detrusor decompensation.

The possible association between serum interleukin 8 and acute urinary retention in Chinese patients with benign prostatic hyperplasia

“…As one of the progressive manifestations and the most serious complications of BPH, AUR implies that the bladder function has been decompensated (Elmissiry et al, 2019), which occurs because of the bladder outlet obstruction. At this stage, even if surgical treatment can relieve the obstruction to a certain extent, the patient's bladder function will still be severely impaired.…”

“…Once it occurs, AUR will seriously affect the quality of life and becomes the primary reason for surgical operation. The occurrence of AUR predicts the decompensation of bladder function, which is closely related to the patient's prognosis (Elmissiry, Ali, Abulfotooh, Moussa, & Ali, 2019; Tubaro et al., 2003). Prior reported studies have shown that patients with a history of AUR have a worse curative effect of transurethral resection of the prostate than patients without a history of AUR (Chen et al., 2012; Wagenlehner et al., 2011).…”

Do functional changes occur in the bladder due to bladder outlet obstruction? ‐ ICI‐RS 2018

“…A three‐stage model can be hypothesized to characterize BOO‐induced bladder remodeling in humans: hypertrophy, compensation (increased detrusor contractility during the voiding phase, often in combination with filling phase detrusor overactivity) followed by the phase of decompensation (detrusor underactivity) . Decompensation and progression to BD correlate with severity and duration of BOO …”

Serum interleukin 6 and acute urinary retention in elderly men with benign prostatic hyperplasia in China: a cross-sectional study

“…Moreover, AUR has been one of the most common reasons for surgical treatment. AUR suggests the presence of a decompensation of bladder function, and bladder dysfunction directly affects patients' prognosis (5,6). An increasing number of studies have shown that, compared with patients without a history of AUR, the efficacy of surgery for BPH patients with a history of AUR is significantly worse (7).…”