Post-Void Residual Urine Volume is Not a Good Predictor of the Need for Invasive Therapy Among Patients With Benign Prostatic Hyperplasia

[Diagnostic work-up of benign prostatic hyperplasia : The German S2e-guideline 2023 part 1]

BACKGROUND

Lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH; in German guidelines: benign prostatic syndrome [BPS]) is the most frequent urological disease in men and can result in a considerable deterioration of quality-of-life. BPS can be associated with LUTS, benign prostatic enlargement (BPE), and bladder outlet obstruction (BOO) or benign prostatic obstruction (BPO), respectively. The expert group on BPS of the German Society of Urology has re-evaluated the tests for the assessment of BPH and provides evidence-based recommendations.

OBJECTIVES

Presentation and evidence-based rating of tests for the assessment of patients with BPS.

MATERIALS AND METHODS

Summary and overview of chapters 5, 6, and 8 of the latest long version of the German S2e guideline on BPS.

RESULTS

The diagnostic work-up should clarify (1) whether the complaints of the patient are caused by BPS, (2) how relevant the complaints are and whether treatment is necessary, (3) whether complications of the lower or upper urinary tract already exist, and (4) which treatment will be most suitable. Baseline assessment should be done in all BPS patients and include history, measurement of LUTS and quality-of-life, urinalysis, serum prostate-specific antigen, post-void residual, ultrasound of the lower urinary tract, including measurements of prostate volume, intravesical prostatic protrusion and detrusor wall thickness, and ultrasound of the upper urinary tract. Additional tests can follow when questions remain unanswered after baseline assessment. These optional tests include bladder diaries, uroflowmetry, serum creatinine, urethrocystoscopy, other noninvasive tests for the determination of BOO/BPO such as penile cuff test, condom catheter method and near-infrared spectroscopy, and other imagining tests such as X‑ray and MRI investigations.

CONCLUSIONS

The updated German S2e guideline summarizes evidence-based recommendations on the diagnostic work-up, including the assessment of the BPS components BPE, LUTS, and BOO/BPO.

Post-voided residual urine ratio as a predictor of bladder outlet obstruction in men with lower urinary tract symptoms: development of a clinical nomogram

PURPOSE

To confirm the correlation between post-void residual urine ratio (PVR-R) and BOO diagnosed by pressure-flow studies (PFS) in males with lower urinary tract symptoms (LUTS) and to develop a clinical nomogram.

METHODS

A consecutive series of patients aged 45 years or older with non-neurogenic LUTS were prospectively enrolled. Patients underwent standard diagnostic assessment for BOO including International Prostatic Symptoms Score, uroflowmetry, urodynamic studies, suprapubic ultrasound of the prostate, and ultrasound measurements of the bladder wall thickness (BTW). PVR-R was defined as follows: PVR-R = (PVR/total Bladder Volume [BV]) × 100). Logistic regression analysis was used to investigate predictors of pathological bladder emptying (BOO) defined as Schafer > II. A nomogram to predict BOO based on the multivariable logistic regression model was then developed.

RESULTS

Overall 335 patients were enrolled. Overall, 131/335 (40%) presented BOO on PFS. In a multivariable logistic age-adjusted regression model BWT (odds ratio [OR]: 2.21 per mm; 95% confidence interval [CI], 1.57-3.09; p = 0.001), PVR-R (OR: 1.02 per %; 95% CI, 1.01-1.03; p = 0.034) and prostate volume (OR: 0.97 per mL; 95% CI, 0.95-0.98; p = 0.001) were significant predictors for BOO. The model presented an accuracy of 0.82 and a clinical net benefit in the range of 10-90%.

CONCLUSIONS

The present study confirms the important role of PVR-ratio in the prediction of BOO. For the first time, we present a clinical nomogram including PVR-ratio for the prediction of BOO.

Analysis of benign prostatic obstruction surgery: A long-term evaluation in a real-life context

Objective: Surgery is the treatment for male lower urinary tract symptoms (LUTS) relat-ed to benign prostatic obstruction (BPO) refractory to pharma-cological treatment or with complications. This study aimed to assess factors associated with the need for surgical reinterven-tion and/or continuation of pharmacological treatment. Materials and methods: A retrospective analysis of patients who underwent prostatic surgery for male LUTS associated with BPO between 1 May 2015 and 1 May 2016, with a minimum follow-up of five years, in an academic tertiary hospital. The type of surgery, preoperative, postoperative and follow-up analysis were collected in a database. Results: A total of 212 patients were included with a mean age of 70 ± 8.66 years at five years follow-up. At 5 years, a total of 86.9% of patients do not need pharmacological treatment and 12% required surgical reintervention. Of the preoperative parameters, it was found a relationship between prior prostatitis and the need for second surgery with an odds ratio of 4.6. Conclusions: Patients should be informed of the potential need for pharmacological treatment following surgery, or even of the need for reintervention. History of prostatitis seems to be a risk factor for reintervention.

A Novel Nomogram Based on Initial Features to Predict BPH Progression

Objectives: The aim of this study was to establish a tool to identify patients at risk for pharmaceutical and surgical interventions for benign prostatic hyperplasia (BPH)-related lower urinary tract symptoms (LUTS) over a 10 year follow-up. Methods: The data of patients with mild to moderate male LUTS undergoing phytotherapy from January to December 2010 were reviewed. Patients were followed for 10 years through medical visits and telephone consultations. The outcomes were (1) treatment switch from phytotherapy or no therapy to alpha-blockers or 5α-reductase inhibitors (5-ARI), and (2) clinical progression (acute urinary retention or need for surgery). Two calibrated nomograms (one for each outcome) were constructed on significant predictors at multivariate analysis. Results: A total of 107 patients with a median age of 55 years at presentation were included; 47% stopped or continued phytotherapy, while 53% switched to alpha-blockers and/or 5-ARI after a median time of 24 months. One-third in the second group experienced clinical progression after a median time of 54 months. Age, symptom score, peak flow rate (Qmax), prostate-specific antigen (PSA), and post-void residual volume were significantly associated with the outcomes. According to our nomograms, patients switching therapy or progressing clinically had average scores of 75% and 40% in the dedicated nomograms, respectively, as compared to 25% and <5% in patients who did not reach any outcome. Conclusions: We developed a nomogram to predict the risk of pharmaceutical or surgical interventions for BPH-related LUTS at 10 years from presentation. On the basis of our models, thresholds of >75% and >40% for high risk and <25% and <5% for low risk of pharmaceutical or surgical interventions, respectively, can be proposed.

Non-invasive evaluation of bladder outlet obstruction in benign prostatic hyperplasia: a clinical correlation study

Objectives: To determine the utility of ultrasonography (US)-derived parameters (e.g. prostate volume [PV], bladder wall thickness [BWT], post-void residual urine volume [PVR], and intravesical prostatic protrusion [IPP]) and uroflowmetry for identifying bladder outlet obstruction (BOO) by correlating them with the results of pressure–flow urodynamic studies (UDS).

Patients and methods: In all, 164 patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH), from May 2016 to December 2018, were included in this study. All had International Prostate Symptoms Score (IPSS), Quality-of-Life (QOL) index, uroflowmetry (including maximum urinary flow rate [Q_max]) and PVR measured by transabdominal US. Pressure–flow UDS were performed on all men and BOO was defined by a BOO Index (BOOI) >40. Men with a Q_max of ≥12.0 mL/s were considered to have ‘good’ flow.

Results: Amongst the 164 men, the mean (SD) age, PV, BWT and Q_max were 66.72 (9.88) years, 51.91 (13.24) mm, 5.07 (0.91) mm, and 8.46 (3.59) mL/s, respectively. In all, 91 (55.49%) patients had BOO with a BOOI >40 and nine (5.49%) had equivocal BOO with a BOOI of 20–40. The IPP was a statistically significant predictor (P < 0.001) of BOO compared with other variables in the initial evaluation. In patients with BOO confirmed by the pressure–flow UDS, IPP Grade III was associated with a higher BOOI than was Grade I and II (P < 0.001).

Conclusion: BWT, PV and PVR in conjunction with IPP are good predictors of clinically significant BOO due to BPH.

Abbreviations: AUC: area under the curve; BOOI: BOO Index; BPO, benign prostatic obstruction; BWT, bladder wall thickness; IPP: intravesical prostatic protrusion; P_det: detrusor pressure; PV: prostate volume; PVR: post-void residual urine volume; Q_max: maximum urinary flow rate; QOL: quality of life; ROC: receiver operating characteristic; (TA)US: (transabdominal) ultrasonography; UDS: urodynamic studies

[Diagnostic procedures and diagnostic strategy for lower urinary tract symptoms/benign prostatic hyperplasia : An overview]

BACKGROUND

Lower urinary tract symptoms due to benign prostatic hyperplasia (LUTS/BPH) is the most common condition affecting the lower urinary tract of men. Evidence-based assessment is the basis for an ideal treatment approach.

OBJECTIVES

To provide an overview of the current status of diagnostic measures for LUTS/BPH.

MATERIALS AND METHODS

Descriptive review of the literature on the diagnosis of LUTS/BPH.

RESULTS

A medical history inquiring about LUTS/BPH symptoms and burden as well as a standardized and validated symptom questionnaire such as the International Prostate Symptom Score (IPSS) are the basis of the assessment. A physical examination including a rectal exam and the ultrasonography of the lower and upper urinary tract are also part of the basic diagnostic workup. Prostate size is ideally measured by transrectal ultrasound. Serum prostate-specific antigen measurement may help to estimate the prostate size and the risk fo progression. It can also be helpful in the detection of prostate cancer. Urine dipstick or sediment is used to exclude urinary tract infection, hematuria, or glucosuria. Voiding dysfunction can be detected by uroflowmetry. In addition to the aforementioned examinations, further tests such as frequency-voiding charts, multichannel urodynamic evaluation, measurement of detrusor wall thickness and X‑ray imaging of the upper urinary tract as well as a cystoscopy may be offered if needed.

CONCLUSIONS

Diagnostics of LUTS/BPH consist of basic exams as well as optional exams and can be used to assess the progression risk, to identify complications and to offer the ideal treatment.

[Fake News BPH - what is really true!]

BACKGROUND

Lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) is the fourth most common and the fifth most costly disease in men aged 50 years or older. Despite the high prevalence of LUTS/BPH in clinical practice and evidence-based guideline recommendations, there are still plenty of misconceptions on the terminology and pathophysiology of the disease, leading to false assumptions and malpractice.

OBJECTIVES

Listing of commonly used false assumptions and clarification of the correct terminology and pathophysiology.

MATERIALS AND METHODS

Critical reflection of 12 selected fake news based on PubMed search.

RESULTS

Average prostate weight in healthy men is 20 g but varies between 8-40 g. The BPH-disease does not progress in stages; therefore, the BPH-classifications according Alken or Vahlensieck should not be used anymore. There is only a weak and inconsistent relationship between bladder outlet obstruction (BOO) and prostate size, diverticula/pseudo-diverticula, postvoid residual, urinary retention or renal insufficiency, which is too unreliable for BOO-diagnosis in the individual patient. Urethro-cystoscopy with grading of the degrees of occlusion of the prostatic urethra and bladder trabeculation is insufficient for BOO-diagnosis. There is no clinically relevant reduction of BOO with licensed BPH-drugs and no convincing data that prostate resection (TURP) has to be complete until the surgical capsule in order to obtain optimal results.

CONCLUSIONS

The reasons for the persistent use of wrong terminology and pathophysiology are diverse. One reason is lack of implementation of evidence-based guidelines into clinical practice due to lack of knowledge, individual beliefs, costs, availability and reimbursement policies. Another reason is the increasing focus on oncology, coupled with underrepresented education and training on BPH.

Expectant long-term follow-up of patients with chronic urinary retention

AIMS

To describe urologic complications in patients with chronically elevated post-void residual (PVR) volumes and to evaluate other related risk factors during a long-term follow-up in patients managed conservatively.

METHODS

Non-neurogenic patients who refused surgical intervention of the prostate and had PVR volumes >300 mL on two or more separate occasions at least 6 months apart were included. We followed this cohort over time, recorded complications and evaluated risk factors for complications.

RESULTS

Twenty-eight men with a mean age of 74 were followed for a median of 56 months (IQR: 26-101 months); 26 had benign prostatic hyperplasia with a median prostate size of 55 cc. Baseline median PVR was 468 cc (IQR: 395-828) and follow-up median PVR was 508 cc (IQR: 322-714). During follow-up, 13 patients (46%) had at least one complication with acute urinary retention being the most common occurring in 10 patients (36%) with 15 episodes. Other complications presented in less than 15%, and no patients developed permanent renal insufficiency. Patients with prostate size ≥ 100 cc had significantly higher total number of acute retention episodes (P-value: 0.01).

CONCLUSIONS

Although the presence of CUR could commonly predispose to episodes of acute retention, severe complications are infrequent although present. Additionally, prostate size may play a role in increasing some adverse outcomes. With proper counseling about different complications, patients with retention who denied surgical treatment can be safely followed for at least 5 years without renal deterioration.

The role of noninvasive testing and questionnaires in urethroplasty follow-up

Urethroplasty is the preferred surgical approach for the management of urethral stricture disease. To date, no standard has been established to evaluate stricture recurrence after urethral reconstruction, though both invasive and non-invasive methods are used widely. In this article we review the role of noninvasive testing and questionnaires in urethral monitoring after urethroplasty.

Management of Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms (LUTS) commonly affect older men. Age-related changes associated with metabolic disturbances, changes in hormone balance, and chronic inflammation may cause BPH development. The diagnosis of BPH hinges on a thorough medical history and focused physical examination, with attention to other conditions that may be causing LUTS. Digital rectal examination and urinalysis should be performed. Other testing may be considered depending on presentation of symptoms, including prostate-specific antigen, serum creatinine, urine cytology, imaging, cystourethroscopy, post-void residual, and pressure-flow studies. Many medical and surgical treatment options exist. Surgery should be reserved for patients who either have failed medical management or have complications from BPH, such as recurrent urinary tract infections, refractory urinary retention, bladder stones, or renal insufficiency as a result of obstructive uropathy.

EAU Guidelines on the Assessment of Non-neurogenic Male Lower Urinary Tract Symptoms including Benign Prostatic Obstruction

CONTEXT

Lower urinary tract symptoms (LUTS) represent one of the most common clinical complaints in adult men and have multifactorial aetiology.

OBJECTIVE

To develop European Association of Urology (EAU) guidelines on the assessment of men with non-neurogenic LUTS.

EVIDENCE ACQUISITION

A structured literature search on the assessment of non-neurogenic male LUTS was conducted. Articles with the highest available level of evidence were selected. The Delphi technique consensus approach was used to develop the recommendations.

EVIDENCE SYNTHESIS

As a routine part of the initial assessment of male LUTS, a medical history must be taken, a validated symptom score questionnaire with quality-of-life question(s) should be completed, a physical examination including digital rectal examination should be performed, urinalysis must be ordered, post-void residual urine (PVR) should be measured, and uroflowmetry may be performed. Micturition frequency-volume charts or bladder diaries should be used to assess male LUTS with a prominent storage component or nocturia. Prostate-specific antigen (PSA) should be measured only if a diagnosis of prostate cancer will change the management or if PSA can assist in decision-making for patients at risk of symptom progression and complications. Renal function must be assessed if renal impairment is suspected from the history and clinical examination, if the patient has hydronephrosis, or when considering surgical treatment for male LUTS. Uroflowmetry should be performed before any treatment. Imaging of the upper urinary tract in men with LUTS should be performed in patients with large PVR, haematuria, or a history of urolithiasis. Imaging of the prostate should be performed if this assists in choosing the appropriate drug and when considering surgical treatment. Urethrocystoscopy should only be performed in men with LUTS to exclude suspected bladder or urethral pathology and/or before minimally invasive/surgical therapies if the findings may change treatment. Pressure-flow studies should be performed only in individual patients for specific indications before surgery or when evaluation of the pathophysiology underlying LUTS is warranted.

CONCLUSIONS

These guidelines provide evidence-based practical guidance for assessment of non-neurogenic male LUTS. An extended version is available online (www.uroweb.org/guidelines).

PATIENT SUMMARY

This article presents a short version of European Association of Urology guidelines for non-neurogenic male lower urinary tract symptoms (LUTS). The recommended tests should be able to distinguish between uncomplicated male LUTS and possible differential diagnoses and to evaluate baseline parameters for treatment. The guidelines also define the clinical profile of patients to provide the best evidence-based care. An algorithm was developed to guide physicians in using appropriate diagnostic tests.

Defining the degree of intravesical prostatic protrusion in association with bladder outlet obstruction

Purpose

The present study was done to define the degree of intravesical prostatic protrusion (IPP) causing bladder outlet obstruction (BOO) in patients with benign prostatic hyperplasia (BPH)/lower urinary tract symptoms.

Materials and Methods

We retrospectively evaluated 239 patients with BPH, analyzing age, IPP, prostate volume, International Prostate Symptom Score (IPSS), and the results from a pressure-flow study. Urethral resistance was quantified by using the BOO index (BOOI), according to the formula BOOI=PdetQmax-2×Qmax (where Pdet is detrusor pressure at the peak flow rate and Qmax is peak flow rate). BOO was defined by a BOOI above 40. Patients with a BOOI below 20 were excluded. Patients were classified into two groups (obstructed and unobstructed groups) by the BOOI. Correlations were determined by logistic regression analysis, and receiver operating characteristic curves were plotted to estimate the optimal cutoff for IPP.

Results

There were significant differences in total prostate volume, postvoiding residual urine (PVR), IPP, and Qmax (p<0.001, p<0.001, p<0.001, and p=0.026, respectively) between the obstructed and unobstructed groups, but there were no significant differences in age (p=0.653), IPSS total score (p=0.624), or quality of life score (p=0.138). IPP had a significant prognosis (p<0.001) but was weakly correlated with prostate volume (p=0.026). The correlation coefficients between IPP and Qmax, PVR, prostate volume, and BOO were 0.551, -0.159, 0.225, and 0.391, respectively. For IPP, the area under the curve was 0.759 (95% confidence interval, 0.657 to 0.861) and the cutoff to indicate BOO was 5.5 mm with 66.7% sensitivity and 80.5% specificity.

Conclusions

An IPP exceeding 5.5 mm was significantly associated with BOO.

[Diagnostics of benign prostate syndrome]

The diagnostic work-up of lower urinary tract symptoms (LUTS) in the German guidelines consists of obligatory and optional diagnostic parameters. Recommendations for assessing LUTS include patient history, symptom questionnaires (IPSS international prostate symptoms score), physical examination, urine analysis, prostate-specific antigen, uroflowmetry, ultrasound examination of the urinary bladder, including postvoid residual urine and ultrasound examination of the upper urinary tract. Optional tests are voiding diary, pressure-flow studies, ultrasound measurement of detrusor wall thickness, urethrocystography and urethrocystoscopy. Ultrasound measurement of detrusor wall thickness in particular has a 95 % positive predictive value in diagnosing bladder outlet obstruction. With all diagnostic parameters it is possible to treat LUTS in a risk-adapted manner.

Benign prostatic hyperplasia and prostate cancer: an overview for primary care physicians

Benign prostatic hyperplasia (BPH) and prostate cancer (CaP) are major sources of morbidity in older men. Management of these disorders has evolved considerably in recent years. This article provides a focused overview of BPH and CaP management aimed at primary care physicians. Current literature pertaining to BPH and CaP is reviewed and discussed. The management of BPH has been influenced by the adoption of effective medical therapies; nonetheless, surgical intervention remains a valid option for many men. This can be accomplished with well-established standards such as transurethral resection of the prostate or with minimally invasive techniques. Prostate cancer screening remains controversial despite the recent publication of two large clinical trials. Not all prostate cancers necessarily need to be treated. Robot-assisted prostatectomy is a new and increasingly utilised technique for CaP management, although open radical retropubic prostatectomy is the oncological reference standard. The ageing of the population of the developed world means that primary care physicians will see an increasing number of men with BPH and CaP. Close collaboration between primary care physicians and urologists offers the key to successful management of these disorders.

Stricture recurrence after urethroplasty: a systematic review

PURPOSE

Urethroplasty remains the gold standard for the management of urethral stricture disease with acceptable long-term success. However, the standard by which stricture recurrence is defined and evaluated after urethral reconstruction remains widely variable. We conducted a systematic review of the urological literature to determine how stricture recurrence is defined and evaluated.

MATERIALS AND METHODS

A systematic review was conducted on all contemporary urethroplasty articles published between 2000 and 2008. Using the term "urethroplasty" 302 articles were identified and evaluated. A total of 86 articles were included in the analysis.

RESULTS

The overall recurrence rate for all reconstructive procedures was 15.6%, which remained stable between 2000 and 2008. Stricture recurrence was determined by a mean of 3 (range 1 to 8) different diagnostic tests. The most common primary diagnostic tests for recurrence were uroflowmetry (56% of articles) and retrograde urethrography (51%). Cystourethroscopy was used as a primary screen to identify stricture recurrence in 25% of articles, and as a secondary procedure in another 21%. Recurrence was defined as the need for an additional surgical procedure or dilation in 75% and 52% of articles, respectively.

CONCLUSIONS

The methods used to determine stricture recurrence after urethroplasty remain widely variable. The use of a standardized surveillance protocol to define stricture recurrence after urethral reconstruction may allow more effective comparison of urethroplasty outcomes across institutions.

Evidence-based guidelines for the management of lower urinary tract symptoms related to uncomplicated benign prostatic hyperplasia in Italy: updated summary

BACKGROUND AND SCOPE

Despite the high prevalence and huge socio-economic impact of benign prostatic hyperplasia (BPH) in Italy, no national guidelines have been produced so far. This is a summary of the first Italian guidelines on the diagnosis and treatment of lower urinary tract symptoms (LUTS) related to uncomplicated BPH, prepared by a multidisciplinary panel under the auspices of the Italian Association of Urologists and introduced in Italy in 2003. An update compiled by the authors is also included.

METHODS

Relevant papers published from 1998 to 2003 (updated to 2006) were identified through a structured literature review and the quality of evidence presented therein was graded according to the Centre for the Evaluation of Effectiveness in Health Administration (CeVEAS) system. Recommendations were based on evidence from the literature, but also on feedback from practitioners and specialists. MAIN FINDINGS/RECOMMENDATIONS: Given the prevalence of BPH, all men aged > or = 50 years of age should be asked about LUTS and informed about disease characteristics and therapeutic options, while sexual function should always be assessed in patients with severe and long-standing LUTS. Initial assessment should include medical history (including drug and co-morbidity history), digital rectal examination, urinalysis, International Prostate Symptom Score-Quality of Life (IPSS-QoL) and a voiding diary, while prostate-specific antigen (PSA) and measurement of prostate volume by suprapubic ultrasonography are indicated in fully informed patients with a life expectancy of > or = 10 years in whom BPH progression could influence treatment choices. QoL considerations should dictate whether to start active treatment. When QoL is not affected by LUTS, watchful waiting is indicated if symptoms are mild, acceptable if they are moderate. When QoL is affected, medical therapy with alpha1-blockers or 5alpha-reductase inhibitors (the latter indicated in patients with increased prostate volume) is appropriate. Combined therapy with alpha1-blockers + 5alpha-reductase inhibitors should only be considered in patients at high risk for progression (prostate volume > 40 mL or PSA > 4 ng/mL), since the incremental cost of combination therapy vs. monotherapy with alpha1-blockers or finasteride is prohibitive. Selection of the type of surgery should be based on the surgeon's experience, the presence of co-morbid conditions and the size of the prostate. Open prostatectomy and transurethral resection of the prostate (TURP) are recommended in patients with acute or chronic retention of urine, and acceptable in obstructed patients with moderate/severe symptoms and worsened QoL. Transurethral incision of the prostate (TUIP) is acceptable when prostate volume is < or = 30 mL. Holmium laser enucleation of the prostate (HoLEP) may be proposed to motivated patients where expert surgeons are available. Transurethral microwave thermotherapy (TUMT) or transurethral needle ablation (TUNA) may be proposed to motivated patients who prefer to avoid surgery and/or do not respond to medical treatment. The possible effects of medical or surgical treatments on sexual function should always be discussed.

CONCLUSIONS

These guidelines are intended to provide a framework for health professionals involved in BPH management in order to facilitate decision-making in all areas and at all levels of healthcare.

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.