Bladder wall thickness in normal adults and men with mild lower urinary tract symptoms and benign prostatic enlargement

Comparison of intravesical prostatic protrusion, prostate volume and serum prostatic-specific antigen in the evaluation of bladder outlet obstruction

AIM

The aims of this study were to define the relationship between intravesical prostatic protrusion (IPP), prostate-specific antigen (PSA) and prostate volume (PV) and to determine which one of them is the best predictor of bladder outlet obstruction (BOO) due to benign prostatic enlargement.

METHODS

A prospective study of 114 male patients older than 50 years examined between November 2001 and 2002 was performed. They were evaluated with digital rectal examination, International Prostate Symptoms Score, PSA, uroflowmetry, postvoid residual urine measurement, IPP and PV using transabdominal ultrasound scan. Statistical analysis included scatter plot with Spearman's correlation coefficients and nominal logistic regression

RESULTS

Prostate volume, IPP and PSA showed parallel correlation. Although all three indices had good correlation with BOO index, IPP was the best. The Spearman rho correlation coefficients were 0.314, 0.408 and 0.507 for PV, PSA and IPP, respectively. Using receiver-operator characteristic curves, the areas under the curve for PV, PSA and IPP were 0.637, 0.703 and 0.772, respectively. The positive predictive values of PV, PSA and IPP were 65%, 68% and 72%, respectively. Using a nominal regression model, IPP remained the most significant independent index to determine BOO.

CONCLUSIONS

All three non-invasive indices correlate with one another. The study showed that IPP is a better predictor for BOO than PSA or PV.

The detrusor muscle: an innocent victim of bladder outlet obstruction

OBJECTIVES

Benign prostatic hyperplasia (BPH) is considered a frequent cause of bladder outlet obstruction (BOO) and lower urinary tract symptoms (LUTS), although the physiopathologic mechanism through which BPH causes LUTS is not clear. Several morphologic and functional modifications of the bladder detrusor have been described in patients with BPH and could play a direct role in determining symptoms. The opinion is spreading that the enlarged prostates in patients with LUTS is nothing more than a mere bystander. Evidence has accumulated, however, supporting the role of BPH-related BOO as the direct cause determining bladder dysfunction and indirectly causing urinary symptoms. The present review addresses the bladder response to BOO, particularly focusing on the physiopathologic cascade that links obstructive BPH to bladder dysfunction.

METHODS

A literature review of peer-reviewed articles has been performed, including both in vivo and in vitro studies on human tissue and animal model experiments.

RESULTS

Epithelial and smooth muscle cells in the bladder wall are mechanosensitive, and in response to mechanical stretch stress caused by BOO, undergo modifications of gene expression and protein synthesis. This process involves several transduction mechanisms and finally alter the ultrastructure and physiology of cell membranes, cytoskeleton, contractile proteins, mitochondria, extracellular matrix, and neuronal networks.

CONCLUSIONS

BOO is the initiator of a physiopathologic cascade leading to deep changing of bladder structure and function. Before being a direct cause of storing-phase urinary symptoms, the bladder is the first innocent victim of prostatic obstruction.

Noninvasive Methods of Diagnosing Bladder Outlet Obstruction in Men. Part 1: Nonurodynamic Approach

PURPOSE

Many methods have been suggested for diagnosing bladder outlet obstruction, as defined by the gold standard of pressure flow studies. Difficulty arises when comparing completely different methods of diagnosing bladder outlet obstruction. A comprehensive review of the literature of the different methods used to diagnose bladder outlet obstruction by noninvasive means was performed with a view to allow such a comparison.

MATERIALS AND METHODS

A MEDLINE search was done of the published literature covering until the end of 2004 on noninvasive methods used to diagnose bladder outlet obstruction. A direct comparison of all different methods was made using the sensitivity and specificity, positive predictive value and likelihood ratio of each test. For many of the techniques these values were calculated from the data presented in the article.

RESULTS

A multitude of methods has been applied to diagnose bladder outlet obstruction. Broadly the methods were divided into nonurodynamic and noninvasive urodynamic methods. Nonurodynamic methods include symptoms, biochemical tests such as prostate specific antigen, ultrasound derived measurements such as post-void residual urine, bladder weight, prostate configuration and size, intravesical prostatic protrusion and the Doppler resistive index. Part 1 of the review explores and discusses the relative merits of the nonurodynamic based methods.

CONCLUSIONS

Ultrasound derived measures such as bladder wall thickness and bladder weight offer a promising possibility of diagnosing bladder outlet obstruction noninvasively. However, further reproducibility and large accuracy studies with better methodological standards are required before they can replace pressure flow studies.

Effects of Selective Alpha-1-Adrenergic Receptor Blockers on Bladder Weight

INTRODUCTION

This study was undertaken to investigate the effects of two different alpha(1)-adrenergic blockers on bladder hypertrophy using ultrasound-estimated bladder weight (UEBW) and to assess the relation between changes in UEBW and other objective and subjective parameters of disease severity in patients with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

41 men were enrolled in the study and they were subjected to either watchful waiting (group 1) or alpha(1)-adrenergic receptor blocker therapy (group 2 with alfuzosin; group 3 with tamsulosin). The patients were investigated by symptom evaluation using the International Prostate Symptom Score (IPSS) and quality of life score (QOL), uroflowmetry and UEBW. The parameters were assessed again 3 months after initiation of treatment and compared with the initial values.

RESULTS

While the mean UEBW increased in group 1 (42.2 +/- 10.3 to 52.5 +/- 12.2 g), it decreased in both the other groups that received alpha-blocker therapy (61.3 +/- 18.7 to 41.1 +/- 13.2 and 59.4 +/- 17.2 to 43.5 +/- 17.6 g, respectively). In groups 2 and 3, the mean UEBW, post-void residual urine, IPSS and QOL values decreased, and the mean maximum flow rate increased. All of the changes in group 2 and all except QOL in group 3 were statistically significant (p < 0.05). The changes correlated well with each other with regard to treatment success. The highest decreases in UEBW were encountered in patients with heavier bladders.

CONCLUSIONS

UEBW decreases with alpha(1)-adrenergic receptor blockers. When used together with the other objective and subjective parameters, UEBW is a promising quantitative parameter as a follow-up tool and can be useful in monitoring the therapeutic effects of alpha(1)-adrenergic receptor blockers.

Ultrasound measurement of detrusor wall thickness in healthy adults

AIMS

Measurements of detrusor wall thickness (DWT) are used to diagnose bladder outlet obstruction (BOO). No values of DWT exist in healthy adults so far. These values, however, are necessary to judge DWT in patients with suspected BOO correctly. The aim of this study was to determine DWT in healthy adults and to investigate if bladder filling, gender, age, or body-mass index (BMI) influences DWT.

MATERIALS AND METHODS

In 55 healthy adult volunteers between 15 and 40 years of age, DWT was measured at the anterior bladder wall with a 7.5 MHz ultrasound probe and with a full bladder. In nine of those volunteers, an urodynamic investigation was performed additionally during which DWT was measured in steps of 50 ml until 300 ml and in steps of 100 ml until the maximum bladder volume.

RESULTS

DWT decreases rapidly during the first 250 ml of bladder filling but, thereafter, remains almost stable until maximal bladder capacity. No statistical difference was found between DWT at 250 ml and DWT at a higher bladder filling. Men had a greater DWT compared to women (1.4 vs. 1.2 mm, P < 0.001). The age and BMI did not have a significant impact on DWT.

CONCLUSIONS

DWT remains stable at a bladder filling of 250 ml. At this state of bladder filling, DWT between different groups are comparable. Men have to be evaluated separately from women.

Upper Urinary Tract Cancer: Location is Correlated with Prognosis

OBJECTIVES

Evaluate prognostic information of anatomical location in patients with upper tract transitional cell carcinoma (UTTCC).

METHODS

Retrospective analysis of 149 upper tract transitional cell carcinoma (UTTCC) patients from a single institute treated surgically between 1988 and 2003.

RESULTS

Transmural tumor growth (pT3 or pT4) was less common in distally located tumors (33%) compared to mid (44%), proximal ureter (75%) or pyelum tumors (41%). Tumor stage was the best predictor of disease specific survival. Distally located tumors had a significantly better survival than proximally located cancers (median survival 53 months versus 16 months for tumors in the proximal ureter). Bladder cancer was found in 73 (49%) patients. Invasive UTTCC were less likely to be associated bladder cancer (RR 0.66, 95%CI 0.43-0.98). In a multivariate analysis both tumor stage and location in the upper tract were predictive of disease specific survival after UTTCC diagnosis.

CONCLUSION

Tumor location in the proximal upper tract predicts stage-independent poor prognosis in patients with UTTCC.

Protection of urinary bladder function by grape suspension

Urinary bladder dysfunction secondary to BPH is a major affliction of aging men. A rabbit model of partial outlet obstruction was used to evaluate the ability of a standardized grape suspension to protect the bladder against obstructive bladder dysfunction.Twenty-four New Zealand White rabbits were separated into four groups of six rabbits each. Groups 1 and 3 were pretreated by oral gavage for 3 weeks with a standardized grape suspension suspended in water; groups 2 and 4 were treated with vehicle. Groups 1 and 3 received sham operations after 3 weeks of treatment; groups 2 and 4 received partial outlet obstruction by surgically placing a silk ligature loosely around the urethra. At 3 weeks following surgery, in vivo and in vitro bladder functions were evaluated. Based on both in vivo and in vitro studies, the grape suspension significantly reduced the severity of obstructed bladder dysfunction. This is consistent with the hypothesis that ischemia is a major etiological factor in obstructive dysfunction, and treatment with antioxidants and membrane stabilization compounds such as those in the grape suspension can be effective in the treatment of obstructive bladder pathology.

Bladder wall tension during physiological voiding and in patients with an unstable detrusor or bladder outlet obstruction

OBJECTIVE

To develop and evaluate a new clinical method for measuring bladder wall tension (BWT) on detrusor contraction during physiological voiding and under pathological conditions, as in experimental trials during subvesical obstruction the ability to generate pressure increases, whereas the contractile force per cross-sectional area of detrusor muscle decreases.

PATIENTS AND METHODS

In all, 24 patients were divided into three equal groups: group 1 (mean age 58, sd 8.6 years) comprised men with bladder outlet obstruction in accordance with the Abrams-Griffiths nomogram; group 2 (four men and four women, 56, sd 7.2 years) had detrusor instability; and group 3 (54, sd 9.6 years) had normal bladder emptying. BWT, as the detrusor force per cross-sectional area of bladder tissue (in N/cm2), was calculated after a urodynamic evaluation and ultrasonographic estimate of bladder wall thickness.

RESULTS

In all patients it was possible to measure BWT; the mean (sd) maximum BWT in group 1 was 9.8 (3.9) N/cm2, in group 2 during bladder instability was 11.7 (2.6) N/cm2 and in group 3 was 2.8 (0.5) N/cm2.

CONCLUSIONS

Estimating BWT in humans is possible by combining a urodynamic evaluation with an ultrasonographic estimate of bladder wall thickness. Further clinical research should elucidate the clinical relevance of BWT under comparable conditions.