Urodynamic pressure flow studies can predict the clinical outcome after transurethral prostatic resection

[Botulinum toxin in male lower urinary tract symptoms (LUTS): What can we expect?]

During the last two decades botulinum toxin has also conquered urology. Botulinum toxin reduces the contractility and sensitivity of the detrusor muscle and relieves pain. It is therefore a promising drug whose use in men also appears promising. The following article highlights the practical relevance of botulinum toxin for male lower urinary tract symptoms (LUTS). But first of all, a distinction must be made between use in male LUTS due to benign prostate syndrome (BPS) and use in cases of overactive bladder (OAB) alone. A differentiated diagnosis and treatment of male LUTS is therefore essential.

Human amniotic fluid stem cells can alleviate detrusor dysfunction caused by bladder outlet obstruction in rats

The present study examined whether bladder detrusor dysfunction due to partial bladder outlet obstruction (pBOO) could be improved after the treatment of human amniotic fluid stem cells (hAFSCs). 72 female rats were grouped into sham operation, pBOO, and pBOO with hAFSCs treatment (pBOO + hAFSCs) for in vitro and in vivo studies. Bladder weight, bladder wall thickness, the ratio of collagen to smooth muscle and the levels of positive CD11b/c and HIS48 cells was significantly increased after pBOO but improved after hAFSCs treatment. Cystometries showed impaired bladder function after pBOO. Protein and mRNA levels of hypoxia inducible factor-1α, CCL2, interleukin-1β, transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), α-smooth muscle actin, collagen I and collagen III were increased at 2 and/or 6 weeks, but proteins and mRNA expressions of protein gene product 9.5 were decreased at 2 and 6 weeks after pBOO. These abnormalities were improved after hAFSCs treatment. The expressions of TGF-β1 and CTGF in cultured detrusor cells of pBOO rats were increased but were improved after hAFSCs treatment. The present results showed hAFSCs treatment could improve bladder detrusor dysfunction in pBOO rats, which may be related to the reduction of inflammatory and pro-fibrotic markers in detrusor muscle cells.

Effect of Transurethral Resection of the Prostate on Urodynamic Parameters in Patients with Benign Prostatic Enlargement with Upper Urinary Tract Dilatation

OBJECTIVE

To evaluate the urodynamic outcomes of transurethral resection of the prostate (TURP) in patients of benign prostatic enlargement (BPE) with upper urinary tract dilatation and correlate with International Prostate Symptoms Score (I-PSS).

METHODS

In this prospective study, patients of BPE with upper urinary tract dilatation from July 2017 to June 2019 were enrolled. At presentation, detailed I-PSS, ultrasonography abdomen, serum creatinine, and serum PSA were recorded. All the patients were catheterized and observed for postobstructive diuresis. At 4 weeks, repeat ultrasound and serum creatinine were recorded. Urodynamic study (UDS) was performed after ensuring sterile urine culture. Patients underwent TURP as per the standard technique. A repeat UDS was performed after 3 months, and analysis was done.

RESULTS

Forty-four patients were enrolled of which data of 37 patients were analyzed. In the filling phase of the UDS, there was a significant decrease in detrusor pressure at the end filling phase from 27 to 9.0 cm H2O after TURP. Maximum cystometric capacity and bladder compliance significantly improved at 3 months following surgery. In the voiding phase, peak flow rate showed a significant increase, postvoid residual urine volume significantly decreased, and peak detrusor pressure marginally decreased following TURP. The I-PSS decreased from 20 ± 8 to 5 ± 6 following TURP.

CONCLUSION

High detrusor pressure and reduced compliance is a risk factor for upper urinary tract dilatation. Changes in the bladder dynamics and resolution of hydronephrosis following TURP reflected in the changes in urodynamic parameters and I-PSS.

Patients with small prostates and low-grade intravesical prostatic protrusion - A urodynamic evaluation

OBJECTIVE

Despite high-grade intravesical prostatic protrusion (IPP) being closely related to bladder outlet obstruction (BOO), up to 21% of patients with low IPP remain obstructed. This study evaluates the characteristics and urodynamic findings of men with small prostates and low IPP.

METHODS

One hundred and fourteen men aged >50 years old with lower urinary tract symptoms (LUTS) were assessed with symptoms, uroflowmetry, serum prostate-specific antigen (PSA), transabdominal ultrasound measurement of prostate volume (PV), IPP and post-void residual urine (PVRU). All patients underwent pressure flow studies. Patients with PV < 30 mL and IPP ≤ 10 mm were examined for parameters correlating with BOO or impaired detrusor contractility.

RESULTS

Thirty-six patients had PV < 30 mL and IPP <10 mm. Nine patients (25.0%) had urodynamic BOO, all with normal bladder contractility. Fourteen patients (38.9%) had poor detrusor contractility and all had no BOO. PV, PVRU and IPP were significantly associated with BOO, with IPP showing greatest positive correlation. Both Qmax and IPP were significantly associated with detrusor contractility. At 5-year follow-up, most patients responded to medical therapy. Only three out of nine patients (33.3%) with BOO eventually underwent surgery, and all had a high bladder neck seen on the resectoscope. Only one patient (7.1%) with poor detrusor contractility eventually required surgery after repeat pressure flow study revealed BOO.

CONCLUSION

In men with small prostates and low IPP, the presence of BOO is associated with higher PV, PVRU and IPP, and most respond well to medical management. BOO can possibly be explained by elevation of the bladder neck by a small subcervical adenoma.

Male bladder outlet obstruction: Time to re-evaluate the definition and reconsider our diagnostic pathway? ICI-RS 2015

The diagnosis of bladder outlet obstruction (BOO) in the male is dependent on measurements of pressure and flow made during urodynamic studies. The procedure of urodynamics and the indices used to delineate BOO are well standardized largely as a result of the work of the International Continence Society. The clinical utility of the diagnosis of BOO is however, less well defined and there are several shortcomings and gaps in the currently available medical literature. Consequently the International Consultation on Incontinence Research Society (ICI-RS) held a think tank session in 2015 entitled "Male bladder outlet obstruction: Time to re-evaluate the definition and reconsider our diagnostic pathway?" This manuscript details the discussions that took place within that think tank setting out the pros and cons of the current definition of BOO and exploring alternative clinical tests (alone or in combination) which may be useful in the future investigation of male patients with lower urinary tract symptoms. The think tank panel concluded that pressure-flow studies remain the diagnostic gold-standard for BOO although there is still a lack of high quality evidence. Newer, less invasive, investigations have shown promise in terms of diagnostic accuracy for BOO but similar criticisms can be levelled against these tests. Therefore, the think tank suggests further research with regard to these alternative indicators to determine their clinical utility.

Comparison of Surgical Outcomes Between Holmium Laser Enucleation and Transurethral Resection of the Prostate in Patients With Detrusor Underactivity

Purpose

Currently, holmium laser enucleation of the prostate (HoLEP) and transurethral resection of the prostate (TURP) are the standard surgical procedures used to treat benign prostatic hyperplasia (BPH). Several recent studies have demonstrated that the surgical management of BPH in patients with detrusor underactivity (DU) can effectively improve voiding symptoms, but comparative data on the efficacy of HoLEP and TURP are insufficient. Therefore, we compared the short-term surgical outcomes of HoLEP and TURP in patients with DU.

Methods

From January 2010 to May 2015, 352 patients underwent HoLEP or TURP in procedures performed by a single surgeon. Of these patients, 56 patients with both BPH and DU were enrolled in this study (HoLEP, n=24; TURP, n=32). Surgical outcomes were retrospectively compared between the 2 groups. DU was defined as a detrusor pressure at maximal flow rate of <40 cm H₂O as measured by a pressure flow study.

Results

The preoperative characteristics of patients and the presence of comorbidities were comparable between the 2 groups. The TURP group showed a significantly shorter operative time than the HoLEP group (P=0.033). The weight of the resected prostate was greater in the HoLEP group, and postoperative voiding parameters, including peak flow rate and postvoid residual urine volume were significantly better in the HoLEP group than in the TURP group.

Conclusions

HoLEP can be effectively and safely performed in patients with DU and can be expected to have better surgical outcomes than TURP in terms of the improvement in lower urinary tract symptoms.

Does prostate size predict the urodynamic characteristics and clinical outcomes in benign prostate hyperplasia?

Aims:

Bladder outlet obstruction (BOO) in large and small prostates is managed in a similar manner despite considerably different pathophysiology, which can result in higher failure rates. We investigate the clinical and urodynamic features and study the outcome of patients with benign prostate hyperplasia (BPH) according to their prostate size.

Subjects and Methods:

We prospectively analyzed 100 BPH patients undergoing urodynamic study between January 2015 and August 2016 and divided them into two groups according to their prostate size: small (≤30 mL) and large prostate (>30 mL) groups. We compared the groups regarding age, International Prostate Symptom Score, maximal flow rate (Qmax), postvoided residual, serum prostate-specific antigen (PSA), prostate volume measured by ultrasonography (USG), and urodynamic findings.

Statistical Analysis Used:

For testing the hypothesis, we used the Chi-square test, Student's t-test, and one-way analysis of variance when comparing between groups and conducted the logistic regression analysis for determining predictive factors of BOO.

Results:

Although the total prostate volume significantly correlated with the PSA, patients with a small prostate had lower Qmax (5.27 ± 4.8 mL/s vs. 6.14 ± 6.66 mL/s; P = 0.74), higher incidence of abnormal baldder capacity (39.9% vs. 31.25%), lower voiding efficiency (39.3 ± 40.5% vs. 40.57 ± 32.11%), low compliance (44.4% vs. 31.3%), higher incidence of indeterminate detrusor contractions (38.9% vs. 37.5%), lower incidence of detrusor underactivity (33.3% vs. 28.1%), lower BOO index (40.9 ± 43.2 vs. 49.10 ± 44.48), lower bladder contractility index (77.8 ± 48.84 vs. 92.09 ± 52.79), and lower PdetQmax (51.44 ± 42.23 vs. 61.38 ± 42.01 cmH₂O). Small prostates had higher failed voiding trials postsurgery.

Conclusions:

BOO patients with a small prostate showed poor urodynamic parameters and reported higher postoperative complications.

Do we need better methods of assessing urethral function: ICI-RS 2013?

AIMS

To assess whether current methods of urethral function assessment are sufficient for clinical requirement.

METHODS

A summary of the debate held at the 2013 meeting of the International Consultation on Incontinence Research Society, with subsequent analysis by the authors.

RESULTS

All reported methods of assessment were reviewed and a summary of reported efficacy and clinical application for each is given. Every method of assessment has limitations as to its use, and in some cases the methods have yet to be proved reliable.

CONCLUSIONS

A gap exists between clinical requirements and the capacity of current urethral function assessments to assist diagnosis. Recommendations are therefore made for future research topics.

Female obstruction after incontinence surgery may present different urodynamic patterns

INTRODUCTION AND HYPOTHESIS

The aim of this study is to report a novel understanding of the urodynamic parameters used to diagnose iatrogenic female obstruction. There is no consensual definition of infravesical obstruction in women. Numerous criteria were designed with arbitrary cutoff values with poor clinical correlation. In order to determine the urodynamic profile of infravesical female obstruction we restricted our analysis to women who acquired voiding disturbances after being submitted to stress urinary incontinence (SUI) surgery.

METHODS

A total of 302 women developed obstructive symptoms or voiding difficulties after SUI operations: 176 cases had had Kelly-Kennedy operations (58.2 %), 50 had had Burch operations (16.5 %), 37 (12.2 %) had had anterior colporrhaphy + abdominal (Burch) operations, 33 (10.9 %) had had sling operations, and 8 (2.6 %) had had Marshall-Marchetti operations. Obstructive urinary symptoms started in 1-120 days after the operation and urodynamic evaluations were done after various periods of time (median 18.4 months). Clinical presentations varied widely with irritative symptoms predominating the picture.

RESULTS

Five patterns of pressure-flow relationships could be identified: (1) elevated pressure and poor flow (7.2 %), (2) normal pressure and poor flow (41.5 %), (3) normal pressure and flow associated with prolonged flow time (24.2 %), (4) poor detrusor contraction and elevated residual volume (12.9 %), and (5) elevated pressure and high flow (14.5 %). No relationship was established amongst the group and the Urinary Distress Inventory questionnaire.

CONCLUSIONS

Infravesical obstruction in women does not fit a single model. As suggested, obstruction in women must be based on broad clinical pictures and urinary complaints.

Transitional zone index and intravesical prostatic protrusion in benign prostatic hyperplasia patients: correlations according to treatment received and other clinical data

Purpose

The aim of this research was to assess the value of the transitional zone index (TZI) and intravesical prostatic protrusion (IPP) from transrectal ultrasonography in evaluating the severity and progression of disease by analyzing the relationship between the 2 parameters and symptoms, clinical history, and urodynamics in benign prostatic hyperplasia (BPH) patients undergoing different treatment.

Materials and Methods

A total of 203 patients receiving medication and 162 patients who underwent transurethral resection of the prostate because of BPH were enrolled in this retrospective analysis. The clinical history and subjective and objective examination results of all patients were recorded and compared after being classified by TZI and IPP level. Linear regression was used to find correlations between IPP, TZI, and urodynamics.

Results

The 2 parameters were found to differ significantly between patients receiving medication and patients undergoing surgical therapy (p<0.05). PSA, maximum flow rate (Qmax), detrusor pressure at Qmax (PdetQmax), and the bladder outlet obstruction index (BOOI) differed according to various TZI levels (p<0.05). In addition, the voiding symptom score, Qmax, and BOOI of subgroups with various IPP levels were also significantly different (p<0.05). Both TZI and IPP had significant effects on Qmax, BOOI, and PdetQmax (p<0.05) and the incidence of acute urinary retention (p=0.000).

Conclusions

The results demonstrated that both TZI and IPP had favorable value for assessing severity and progression in patients with BPH. Further studies are needed to confirm whether the two parameters have predictive value in the efficacy of BPH treatment and could be considered as factors in the selection of therapy.

Bladder contractility and urethral resistance relation: what does a pressure flow study tell us?

Hydrodynamic analysis of a pressure flow study is the only reliable method to determine the presence or absence of a bladder outlet obstruction, especially benign prostatic obstruction. To interpret the results of pressure flow study in benign prostatic obstruction, understanding the outlines of the basic theory about evaluation of the relationship between bladder contractility and urethral resistance relation is of paramount importance. In contrast, hydrodynamic analysis of pressure flow study in conditions other than benign prostatic obstruction is complicated by the limits of theories about the hydrodynamics of the lower urinary tract. In this review, the proposed hydrodynamic theories about the relationship between bladder contractility and urethral resistance relation are outlined. Then, problems encountered in the application of hydrodynamic analysis of pressure flow study to diseases other than benign prostatic obstruction are discussed.

Analysis of the Pressure-Flow Study in Weak Detrusor Patients with Benign Prostatic Hypertrophy

OBJECTIVE

Pressure-flow study is a method used to evaluate the degree of bladder outlet obstruction and the strength of detrusor contractility during voiding. However, whether or not the operation for benign prostate hyperplasia should be avoided in detrusor underactivity patients remains controversial. To address this, we performed a retrospective analysis of our pressure-flow study data for benign prostate hyperplasia patients. We especially focused on the backgrounds of patients with weak detrusor contractility.

METHODS

Patients (n = 288; average age, 71.5 years) who underwent pressure-flow study to evaluate operative indications between February 2001 and April 2010 were included in this study. We analyzed the relationships between background factors and detrusor contraction strength according to Schäfer's nomogram.

RESULTS

Patients with weak detrusor contractility had poor flow (5.81 mL/sec) and low voided volume (141.2 mL) compared to patients with normal (8.77 mL/sec, 202.0 mL) or strong (8.97 mL/sec, 178.3 mL) detrusor contractility. Twenty-six of 74 weak detrusor patients underwent prostate operation. The operated group had high obstruction grade (3.35, P < 0.001), but a low rate of detrusor overactivity (19.2%, P < 0.05), compared to the non-operated group (2.16, 41.7%). The operated group also had high urinary retention rate (38.5%) compared to the non-operation group (18.8%).

CONCLUSION

We performed prostate surgery in patients who had episodes of urinary retention, with outlet obstruction, and with no detrusor overactivity, even in those with weak detrusor contractility. The operation may not be contraindicated for these patients. Pressure-flow study is an important tool to ensure adequate informed consent.

Importance of prostate volume and urinary flow rate in prediction of bladder outlet obstruction in men with symptomatic benign prostatic hyperplasia

OBJECTIVES

To predict bladder outlet obstruction with parameters of non-invasive investigations for patients with symptomatic benign prostatic hyperplasia.

PATIENTS AND METHODS

A sample of 122 men with moderate to severe lower urinary tract symptoms suggestive of benign prostatic hyperplasia was selected. Transrectal prostate ultrasound, free flow measurement, and transabdominal ultrasound for residual urine were carried out together with digital rectal examination for all patients. All patients underwent urodynamic pressure/flow test. Two groups of obstructed (91 patient) and equivocal/unobstructed (31 patient) were analyzed. Probabilistic model based on logistic regression was developed for prediction of obstruction.

RESULTS

Various parameters were compared in obstructed and non-obstructed/equivocal groups, highlighting important parameters for obstruction. Correlation analysis indicates higher obstruction dependence on average and peak flow rates and lower dependence on total prostate and transition zone volumes, transition zone index. Binary logistic regression model suggests that average flow rate combined with total prostate volume is the best predictor of obstruction (83% of correct predictions; PPV = 92%; NPV = 52%) in the analyzed sample. The analyzed model suggests that peak flow rate could also be almost equally important parameter instead of average flow rate.

CONCLUSIONS

The study suggests that average/peak flow rate combined with total prostate volume can be used for prediction of obstruction. The developed probabilistic model helps to determine patients who need invasive urodynamic testing for decision on surgical treatment.

A new algorithm in patients with elevated and/or rising prostate-specific antigen level, minor lower urinary tract symptoms, and negative multisite prostate biopsies

Patients with elevated and/or rising prostate-specific antigen (PSA), minor lower urinary tract symptoms (LUTS), and no evidence for prostate cancer on (multiple) extended prostate biopsies are a regularly encountered problem in urological practice. Even now, patients are seen with no objective explanation of this persistent elevated and/or rising PSA. So far, many strategic proposals have been elaborated and published to deal with this specific population including the use of different PSA derivates; applying different biopsy schemes—strategies—biopsy target imaging; diagnostic use of prostate cancer genes; and many more. In this review, we propose a new algorithm in which an urodynamic evaluation should be included since bladder outlet obstruction (BOO) can be expected. Once BOO is confirmed, a transurethral resection of the prostate (TURP) can be offered to these patients. This procedure will result in subjective and biochemical improvement and allows extensive histological examination. Current literature was reviewed with regard to this specific population. This research was performed using the commercially available Medline online search tools and applying the following search terms: “diagnostic TURP”; “elevated PSA”; and “prostate biopsy”. Furthermore, subsequent reference search was executed on retrieved articles.

Persistent detrusor overactivity after transurethral resection of the prostate

Detrusor overactivity is associated with aging and benign prostatic obstruction and often causes the troublesome symptoms of urgency and urgency incontinence (overactive bladder), persistent detrusor overactivity after transurethral resection of the prostate being the cause of more than a third of poor symptomatic outcomes following surgery. Most of the evidence currently suggests that neurons of the urothelium at the bladder neck play a significant role in the genesis of detrusor overactivity. Treatment options including botulinum toxin injections and intravesical vanilloids have been studied in the treatment of persistent detrusor overactivity, but further studies are needed specifically in patients with persistent detrusor overactivity after transurethral resection of the prostate. As urodynamic studies are able to predict a proportion of postoperative failures, more widespread use is advocated by many in the routine assessment of lower urinary tract symptoms thought to be due to benign prostatic obstruction.

Urodynamics: what to do and when is it clinically necessary?

The role of urodynamics in the evaluation and treatment of men with lower urinary tract symptoms is not well defined. Symptoms do not correlate very well with urodynamic findings, but patients with prostatic obstruction fare better after ablative prostatic surgery than those with impaired detrusor contractility. The only proven method for distinguishing between the two is urodynamics, ie, the detrusor pressure/uroflow study. This article reviews urodynamic techniques and the literature pertaining to urodynamics, along with their clinical utility in benign prostatic hyperplasia. The role of urodynamics in clinical practice is discussed as well.

Rising PSA in patients with minor LUTS without evidence of prostatic carcinoma: a missing link?

OBJECTIVES

To determine the role of pressure flowmetry in patients without bothersome lower urinary tract symptoms (LUTS), rising prostate-specific antigen (PSA) levels and diagnosed as having clinical benign prostatic hyperplasia (BPH) after negative (multiple) extended multi-site biopsy.

METHODS

The study enrolled patients with minor LUTS who were referred to our urological practice by their general practitioner because of a rising PSA level (>/=4 ng/ml). After exclusion of clinical prostatic carcinoma by digital rectal examination and transrectal ultrasound, all patients underwent at least one set of extended multi-site biopsies to exclude T1c prostate cancer. Patients with negative biopsies (clinical BPH) were subjected to pressure flowmetry whereafter those with bladder outlet obstruction underwent TURP.

RESULTS

The study included 82 patients, with a mean age of 64.8 years (50.2-78.2 years), satisfying the inclusion criteria. Urodynamic analysis showed that all patients had bladder outlet obstruction. After TURP, eight patients (9.8%) were diagnosed as having histologically proven prostate cancer; 74 patients (90.2%) were diagnosed as having BPH. Patients of the BPH group had a mean preoperative PSA level of 8.8 ng/ml (4.3-25.8 ng/ml) and a mean international prostate symptom score of 8.8 (2-18). The mean detrusor pressure at maximum flow in BPH patients was 89.5 cmH(2)O (20-200 cmH(2)O).

CONCLUSIONS

An increased PSA in patients with minor or no LUTS, clinical BPH and negative extended multi-site prostate biopsy is strongly correlated to bladder outlet obstruction. Therefore, patients with these characteristics should be treated with TURP.

Analysis of prognostic factors regarding the outcome after a transurethral resection for symptomatic benign prostatic enlargement

AIMS

To identify preoperative predictive variables regarding treatment outcomes following transurethral resection of the prostate (TURP) of patients with symptomatic benign prostatic enlargement (BPE).

METHODS

A retrospective study was conducted in 384 patients of 1,397 men who had undergone TURP for symptomatic BPE. All the patients had completed the evaluation of International Prostate Symptom Score (I-PSS), and quality of life (QOL) index, and had undergone full urodynamics before the surgery. Outcomes were assessed at 12 months after surgery. The association between baseline variables and the improvement in outcome variables was statistically analyzed.

RESULTS

Preoperative urodynamic abnormalities included bladder outlet obstruction (BOO) in 315 (82.0%), detrusor underactivity in 91 (23.7%), and detrusor overactivity (DO) in 160 (41.7%). Multivariate analysis showed that the presence of DO and a higher degree of BOO were both associated with postoperative improvement both in I-PSS and the QOL. The initial level of storage symptoms correlated with an improvement in the QOL.

CONCLUSIONS

The association between those variables obtained by preoperatively performed urodynamic analysis and the degree of improvement in lower urinary tract symptom and QOL following TURP was statistically elucidated in a large number of patients with symptomatic BPE. A higher degree of baseline BOO positively predicts the postoperative improvement in I-PSS and QOL, while the baseline DO negatively predict it.

TURP and low-energy TUMT treatment in men with LUTS suggestive of bladder outlet obstruction selected by means of pressure-flow studies: 8-year follow-up

AIMS

To evaluate the long-term outcome of transurethral resection of the prostate (TURP) and transurethral microwave thermotherapy (TUMT) in men with symptomatic benign prostatic hyperplasia (BPH), when allocation to the treatment-group was based on urodynamic diagnosis of bladder outlet obstruction (BOO).

METHODS

A total of 231 elderly men with symptomatic BPH were treated either by TURP or by low-energy TUMT. A pressure-flow study was performed to detect the obstruction and to help in the selection of the two treatments. The patients were examined at baseline then checked again after 2 and 8 years.

RESULTS

At 2 years of follow-up there was a significant improvement for both IPSS and QoL (P < 0.0001) in both groups of treatment. This was accompanied by a significant improvement (P < 0.0001) in the maximum flow rate from 10.0 (5.8) to 16.4 (7.6) in the TURP group and from 12.1 (5.2) to 14.9 (5.7) in the TUMT group. These findings persisted at 8 years, they were, however, more pronounced after TURP. The overall retreatment rate reached a value of 11% in the TURP group and 27% in the TUMT group, respectively. At the follow-up, 95% of the patients who underwent TURP and 70% of the patients treated by TUMT claimed to be satisfied with that choice.

CONCLUSIONS

With durable symptomatic improvement and lowest retreatment rate, TURP still presents a standard treatment option for patients with severe BOO. Low-energy TUMT has sufficiently relieved patients' symptoms and can be offered to less obstructed patients as an alternative.

Can the outcome of transurethral resection of the prostate be predicted preoperatively?

OBJECTIVES

To establish a formula for predicting the outcome of transurethral resection of the prostate using noninvasive parameters of preoperative evaluation.

METHODS

The data of 54 men with a mean age of 57 years (range 43 to 78) were retrospectively analyzed. The International Prostate Symptom Score, quality-of-life score of the International Prostate Symptom Score questionnaire, maximal flow rate (Qmax) recorded during uroflowmetry, age, prostate volume calculated by transrectal ultrasonography, postvoid residual urine volume, and results of pressure-flow studies were evaluated to find a formula that would predict the outcome of transurethral resection of the prostate. The patients were evaluated by uroflowmetry, postvoid residual urine volume determination, and International Prostate Symptom Score questionnaire at 3 months postoperatively. Four different success criteria were investigated with the calculated equations.

RESULTS

According to the discriminant analysis, two new scores were calculated as S(1) = (0.169 x age) - (0.0075 x Qmax) and S2 = (0.168 x age) - (0.095 x Qmax) - (0.007 x detrusor pressure at Qmax). For the four success criteria, the optimal cutoff, obtained from the receiver operating characteristic curves of S(1) and S(2), was 8.83 and 9.21, respectively. A statistically significant difference was not found between S1 and S2. The S1 formula had a sensitivity between 71.8% and 85.2%, specificity between 71.4% and 86.7%, and positive predictive value between 72.2% and 92.9% for the four different criteria using two simple variables (Qmax of uroflowmetry and age).

CONCLUSIONS

Because urodynamic parameters did not add benefit to the formula consisting of age and Qmax of uroflowmetry with considerable sensitivity and specificity, performing urodynamic studies might not be useful for predicting the outcome of transurethral resection of the prostate.

Serum prostate-specific antigen to predict the presence of bladder outlet obstruction in men with urinary symptoms

OBJECTIVE

To determine whether prostate specific antigen (PSA) level can usefully predict or exclude bladder outlet obstruction (BOO), in men with lower urinary tract symptoms (LUTS).

PATIENTS AND METHODS

A cohort of men from 1996 to 1999 who had LUTS caused by BPH was evaluated by serum PSA and pressure-flow urodynamic studies, and a blinded comparison made. The settings were teaching hospitals in London, UK and L'Aquila, Italy. Men (302) were referred by primary-care practitioners with LUTS and a PSA of < 10 ng/mL. Regression analysis was used to predict the extent of BOO, and create likelihood ratios and predictive values for BOO according to the PSA value.

RESULTS

PSA was significantly associated with BOO (P < 0.001; r2 0.07), with significant likelihood ratios altering the probability of BOO. If the PSA was > 4 ng/mL, mild or definite BOO was likely (89%), whereas if the PSA was <2 ng/mL, there was about a one-third chance each of no, mild and definite BOO.

CONCLUSION

High PSA levels in patients with LUTS are significantly associated with BOO; low PSA levels mean that definite BOO is unlikely.

International prostate symptom score - IPSS - AUA as discriminat scale in 400 male patients with lower urinary tract symptoms (LUTS)

OBJECTIVE

This study analyzed the total symptom score, irritative and obstructive domains of IPSS questions regarding quality of life and the urodynamic diagnosis in 400 men with LUTS.

MATERIALS AND METHODS

Four hundred consecutive male patients were prospectively enrolled after being submitted to full urodynamic evaluation and IPSS. Obstructed and non-obstructed patients were compared regarding the symptoms score and quality of life. Results were assessed through Wilcox, ANOVA and Student-t tests.

RESULTS

80.2% were diagnosed as urodynamically obstructed of which 42.4% presented detrusor instability in the filling phase. In obstructed patients there were no statistical difference concerning obstructive or irritative questions from IPSS (p = 0.50). It was not possible either to predict which patients presented detrusor instability based on the questionnaire (p = 0.65). Out of seventy-nine cases unobstructed (19.8%), 65.4% revealed detrusor instability. These cases could not be distinguished from all obstructed men based on the clinical questions measured by IPSS (p = 0.87). Obstructive and irritative questions did not present different indexes than obstructed cases (p = 0.63). Subjective quality of life index did not discriminate obstruction nor it could predict detrusor instability in both groups.

CONCLUSION

Clinical symptoms and quality of life index measured by the IPSS as well as its obstructive and irritative domains do not have discriminating power to predict the presence of infravesical obstruction in males with LUTS, demanding objective tools to demonstrate obstruction.

Effect of bladder outlet obstruction on detrusor smooth muscle cell: an in vitro study 1, 2 1Presented at the 6th Asian Congress of Urology (6th ACU), Kuala Lumpur, Malaysia, August 12–18, 2002 2This study was supported by a grant from National Natural Science Fund (No. 39970739), China, PRC

BACKGROUND

Although relieving obstruction is generally curative on bladder outlet obstruction (BOO), bladder dysfunction persists in some patients. Repetitive stretch and relaxation applied to cultured bladder smooth muscle (SM) cells in vitro have been used to mimic increases in urodynamic load experienced by the detrusor muscle under conditions of BOO. We first clarified the relationship between phenotype transformation and biomechanical properties of detrusor smooth muscle cell (DSMC) subjected to the cyclic mechanical stretch.

MATERIALS AND METHODS

Cultured rat DSMC were grown on collagen-coated silicone membranes and subjected to continuous cycles of stretch-relaxation. All experiments were performed on cells between passages 2 and 4. Each cycle consists of 5 seconds of stretch and 5 seconds of relaxation. The computer controlled vacuum induced 10% (1), 20% (2), and 30% (3) maximum elongation of the plate membrane at different designed pressures. The deoxyribonucleic acid synthesis rate was assessed by performing tritiated thymidine incorporation assay. The expression of SM-alpha-actin and proliferation of DSMC were analyzed by immunofluorescent assay and flow cytometry. The image analysis and micropipet aspiration systems were used to investigate the single cell contraction and viscoelasticity. Using the 3-element standard linear solid model, the elastic modulus K(1), K(2), and viscoelastic coefficient mu were determined, which show the passive deformation ability of detrusor cells.

RESULTS

As the basic structural changes to mechanical stretch, DSMC undergo phenotypic modulation from their normal contractile phenotype to a "synthetic" phenotype: the DSMC become more proliferative and the actin less organized along the cell's long axis. The cell proliferation index of control and stretched group (10%, 20%, 30% elongation) are 0.24, 0.43, 0.58, and 0.65, respectively. The actin filaments in unstimulated cells were evident and orientated along the major axis of the cell. After mechanical stretch, the well-spread filaments changed their orientation. The function, such as contraction, and viscoelasticity of a single DSMC subjected to stretch both decreased significantly compared with control. The maximum contractile velocity and maximum cell length shortening rate of group 3 (30% elongation) showed significant decreases compared with unstretched control (P < 0.01). K(1) and K(2) were decreased with the increase of mechanical overload. However, there was no statistic difference between groups 2 and 3.

CONCLUSIONS

Functional abnormalitie of BOO have the structural basis: phenotype transformation (i.e., remodeling) of the detrusor cells. Cyclic stretch and relaxation applied to DSMC in vitro can be used to model increases in urodynamic load experienced by the bladder detrusor muscle under conditions of BOO. Phenotype transformation is the structural basis of functional changes of DSMC subjected to periodic overload mechanical stretch.