Voiding dysfunction in men: pathophysiology and risk factors

Changes of resistance indices after medication in benign prostatic hyperplasia: a prospective study

Background

This study aimed to determine the relationship between resistive indices (RIs) and changes in prostate size after medical treatment in patients with benign prostatic hyperplasia (BPH).

Methods

A total of 86 patients with BPH were included in the study, excluding 42 patients with a total prostate volume (TPV) of <30 cc or taking α1-adrenergic blockers and 5α-reductase inhibitors (5ARI) before study participation. Therefore, the data for 44 patients were analyzed. All patients were treated with α1-adrenergic blockers and 5ARIs. The variables examined were prostate-specific antigen, International Prostate Symptom Score, quality of life score, maximal urinary flow rate, residual urine volume, TPV, transition zone volume, and RIs of the urethral artery and left and right capsular arteries. These variables were assessed at baseline and after 3 and 6 months of treatment.

Results

The mean TPV was 43.5 ± 10.9 and decreased to 35.2 ± 11.5 and 33.9 ± 9.8 after 3 and 6 months of treatment, respectively (p < 0.001). The mean RI of the urethral artery, right capsular artery, and left capsular artery at pretreatment did not decrease significantly. However, comparing the baseline with 3-month data, TPV at 3 months/TPV at baseline was significantly correlated with RI changes in the left capsular artery (r = 758; P < 0.001).

Conclusion

In patients with BPH, α1-adrenergic blocker and 5ARI medications for 3 and 6 months did not result in a significant reduction in the RI of the urethral artery and both capsular arteries. Larger scale, prospective studies are needed to evaluate the relationship between TPV and RI reductions.

Correlations between bladder wall thickness and clinical manifestations in female patients with detrusor underactivity and detrusor overactivity-with-detrusor underactivity

BACKGROUND

Among female patients with lower urinary tract symptoms, detrusor underactivity (DU), and detrusor overactivity-with-detrusor underactivity (DO-DU) are two common diagnoses. Here, we investigated the correlations between bladder wall thickness (BWT) and clinical manifestations of the two diagnoses.

METHODS

From 2011 to 2016, female patients with DU or DO-DU, diagnosed at our institute, were recruited. We analyzed their urodynamic parameters and collected three questionnaires (IPSS, UDI-6, OABSS). Using transabdominal sonography, the BWT was recorded. DU was defined as follows: maximum free flow rate (Qmax) ≤ 15 cc/s; detrusor pressure at maximum flow (PdetQmax) ≤ 20 cmH2O; bladder capacity > 150 cc. DO-DU was defined as follows: Qmax ≤ 15 cc/s; PdetQmax ≤ 20 cmH2O; bladder capacity ≤ 150 cc. The BWTs of the two groups were compared using the Mann-Whitney U test; the correlations among the BWTs and the results of three questionnaires were analyzed using Spearman's rank correlation coefficient.

RESULTS

Forty-eight female patients with DU and 13 with DO-DU were recruited. Demographic data revealed no differences between the two groups. The mean BWT of the DO-DU patients was significantly larger than that of the DU patients (4.11 vs 3.42 mm; p = 0.001). In the DO-DU group, a high correlation existed between the BWT and some of the UDI-6 items (urgency incontinence: r = 0.831, p = 0.006; incontinence related to activity: r = 0.884, p = 0.002; small amounts of leakage: r = 0.809, p = 0.008). The BWT of the DO-DU patients also exhibited a moderate correlation with the urgency incontinence from the OABSS questionnaire (r = 0.679; p = 0.044). No correlations existed between the BWT of the DU patients and any of the data from the three questionnaires.

CONCLUSION

The BWT in the DO-DU patients was significantly thicker than that in the DU patients. The DO-DU patients with thicker bladder walls also had higher UDI-6 scores for both urgency and urgency incontinence.

Prostatic collagen architecture in neutered and intact canines

BACKGROUND

Prostate stiffness and increased collagen content both associate with the presence of urinary symptoms in men but mechanisms responsible, including impact of age and androgens, are unknown. Dogs develop prostate-related urinary dysfunction similar to humans, but mechanisms are also unknown. Mice have been used to examine how prostatic collagen accumulation affects voiding but whether mouse prostatic collagen organization resembles human or dog has not been evaluated. Here, we have constructed the first comprehensive, comparative maps of collagen architecture in canine, human, and mouse prostate and test whether canine prostatic collagen content is increased by aging and reduced by castration.

METHODS

Complete transverse prostate sections were stained with picrosirius red and imaged with confocal microscopy to reveal and compare collagen architecture across species. Canine prostatic collagen fiber length, diameter, and density in prostatic urethral, periurethral, peripheral, and capsular regions were quantified and compared among four experimental groups: young intact, young neutered, old intact, and old neutered dogs.

RESULTS

Surprisingly, the majority of collagen was localized to the prostatic urethra in canine, human, and mouse. In canine and human, capsular regions also featured a dense collagen network but it appeared less dense than around prostatic urethra. Older, intact male canines exhibited overall denser prostate collagen fibers and had thicker capsular fibers than young, intact males. Prostatic glandular regions undergo dramatic atrophy and regression following castration, and our finding of neutered animals having increased collagen fiber density in both periurethral and peripheral regions is consistent with glandular contraction and increased proportion of stroma.

CONCLUSIONS

Collagen architecture in dog appears similar to that in humans when cross sections are compared side-by-side. Canine collagen organization is affected by both age and androgen status, suggesting these factors may contribute to collagen accumulation in some males.

Lower Urinary Tract Symptoms, Benign Prostatic Hyperplasia, and Urinary Retention

Lower urinary tract symptoms (LUTS) consist of a common set of urologic symptoms that can affect the elderly. The prevalence of LUTS is expected to rise owing to the continued increase of numbers of the elderly. Although benign prostatic hyperplasia is considered a common cause of LUTS, the broader potential causes of LUTS are myriad. A wide range of diagnostic modalities and treatments are available to manage patients with LUTS and their utilization should not be limited to the urologist.