Detrusor contraction power parameters (BCI and W max) rise with increasing bladder outlet obstruction grade in men with lower urinary tract symptoms: results from a urodynamic database analysis

Effect of bladder filling volume on detrusor contractility in men with bladder outlet obstruction

INTRODUCTION

Bladder outlet obstruction alters detrusor contractility, reducing the bladder's ability to respond to large filling with a risk of urinary retention. The objective was to assess the effect of bladder filling volume on detrusor contractility in men with bladder outlet obstruction.

METHODS

A prospective multicenter study in two pelviperineology departments. Male patients eligible for urodynamics (IPSS score > 7) were included from January to July 2022. In case of absence of bladder outlet obstruction on pressure-flow studies, they were secondarily excluded. The primary endpoint was the maximum isometric detrusor pressure during a stop-test, corresponding to detrusor contractility, measured at 3 filling volumes (50%, 75%, and 100% of cystometric capacity).

RESULTS

Fifty-two patients performed urodynamics, of whom 12 were excluded because of lack of obstruction or inability to perform the stop-test. Detrusor contractility was significantly higher for a 75% bladder filling than 50% and for a 75% filling than 100%, with a mean difference of 19.5; confidence interval (CI) 95% [14.3; 24.8] and 12.2; CI 95% [6.9; 17.5] cmH₂ O respectively (p < 0,01).

CONCLUSION

In case of bladder outlet obstruction in men, detrusor contractility depends on bladder filling volume, with reduced contractility when the bladder was underfilled or overfilled. This phenomenon could help to explain the mechanisms of urinary retention in men with bladder outlet obstruction.

Detrusor Underactivity in Men with Bladder Outlet Obstruction

Detrusor underactivity (DU) and bladder outlet obstruction (BOO) are both common troublesome causes of lower urinary tract symptoms (LUTS) and often impact on quality of life simultaneously in men. This article aims to focus on DU with BOO in male patients.

METHODS

Original articles concerning DU with BOO were identified through literature research from PubMed and EMBASE database. We selected 38 articles in our review, including those concerning pathophysiology, evaluation, treatment and predictors for a successful BOO surgery for DU.

RESULTS

DU from BOO can result from several pathophysiological mechanisms. Although urodynamic study (UDS) is considered as a precise method to diagnose DU and BOO, there are some previous studies which proposed a non-invasive method to identify DU related to BOO. The treatment goal of DU is restoring bladder contractility using medication or surgery. Releasing outlet obstruction and resistance is the main strategy to restore bladder contractility when medication to directly increase bladder contractility has had limited efficacy.

CONCLUSIONS

DU from BOO is poorly understood and is largely under-researched. The etiology and pathophysiology still need to be evaluated. Effective and safe medication to restore bladder contractility is also lacking. It remains valuable to perform further research to reveal the unknown aspects of DU.

Tradução para a língua portuguesa do artigo original em inglês “ The International Continence Society (ICS) report on the terminology for adult male lower urinary tract and pelvic floor symptoms and dysfunction”

Introdução

No desenvolvimento da terminologia do trato urinário inferior, devido à sua crescente complexidade, a terminologia para os sintomas e a disfunção do trato urinário inferior masculino e assoalho pélvico precisa ser atualizada, utilizando abordagem específica masculina e por meio de um relatório de consenso clinicamente embasado.

Métodos

Este relatório combina a contribuição de membros do Standardisation Committee da International Continence Society em um Grupo de Trabalho com especialistas reconhecidos no campo, assistido por muitos julgadores externos. Categorias clínicas centrais apropriadas e uma subclassificação foram desenvolvidas para fornecer uma codificação numérica para cada definição. Um extenso processo de 22 rodadas de revisão interna e externa foi desenvolvido para examinar exaustivamente cada definição, com tomada de decisão por opinião coletiva (consenso).

Resultados

Um relatório de terminologia para os sintomas e a disfunção do trato urinário inferior e do assoalho pélvico foi desenvolvido, abrangendo cerca de 390 definições/descritores separados. É clinicamente embasado nos diagnósticos mais comuns definidos. A clareza e a facilidade de uso foram os principais objetivos para torná-lo interpretável por profissionais e estagiários em todos os diferentes grupos de especialidades envolvidos na disfunção do trato urinário inferior e do assoalho pélvico masculino. Imagens específicas para homens (ultrassonografia, radiologia, tomografia computadorizada e ressonância magnética) foram um adicional importante, enquanto figuras apropriadas foram incluídas para complementar e ajudar a esclarecer o texto.

Conclusões

Um relatório de terminologia com base em consenso para sintomas e disfunção do trato urinário inferior e do assoalho pélvico masculino foi produzido visando ser um auxílio significativo para a prática clínica e um estímulo para a pesquisa.

Cluster analysis of men undergoing surgery for BPH/LUTS reveals prominent roles of both bladder outlet obstruction and diminished bladder contractility

Lower urinary tract symptoms (LUTS) in aging men are commonly attributed to bladder outlet obstruction from benign prostatic hyperplasia (BPH) but BPH/LUTS often reflects a confluence of many factors. We performed a hierarchical cluster analysis using four objective patient characteristics (age, HTN, DM, and BMI), and five pre-operative urodynamic variables (volume at first uninhibited detrusor contraction, number of uninhibited contractions, Bladder Outlet Obstruction Index (BOOI), Bladder Contractility Index (BCI) and Bladder Power at Qmax) to identify meaningful subgroups within a cohort of 94 men undergoing surgery for BPH/LUTS. Two meaningful subgroups (clusters) were identified. Significant differences between the two clusters included Prostate Volume (95 vs 53 cc; p-value = 0.001), BOOI (mean 70 vs 49; p-value = 0.001), BCI (mean 129 vs 83; p-value <0.001), Power (689 vs 236; p-value <0.001), Qmax (8.3 vs 4.9 cc/sec; p-value <0.001) and post-void residual (106 vs 250 cc; p-value = 0.001). One cluster is distinguished by larger prostate volume, greater outlet resistance and better bladder contractility. The other is distinguished by smaller prostate volume, lower outlet resistance and worse bladder contractility. Remarkably, the second cluster exhibited greater impairment of urine flow and bladder emptying. Surgery improved flow and emptying for patients in both clusters. These findings reveal important roles for both outlet obstruction and diminished detrusor function in development of diminished urine flow and impaired bladder emptying in patients with BPH/LUTS.

[Sophisticated surgical management of distinctive patients with benign prostatic hyperplasia (BPH)]

Herein we describe four clinical scenarios. For the standard patient (prostate volume 30-80 ml, life expectancy >10 years) transurethral resection of the prostate (TURP) remains the standard of care, while endoscopic enucleation is a valuable alternative. Patients with a relevant middle lobe profit most from TURP, endourological enucleation procedures, or laser vaporization. In the case of the absence or a moderate-sized middle lobe and the absence of severe bladder outlet obstruction (BOO), minimally invasive procedures such as Rezūm®, UroLift® or prostate artery embolization (PAE) can be offered. Patients have to be informed that long-term data on this specific indication are lacking. Particularly younger men requiring BPH surgery are interested in preserving ejaculatory function. In the presence of severe BOO, ejaculatory-protective TURP or endoscopic enucleation by preserving the pericollicular region or aquablation are the methods of choice providing an antegrade ejaculation in 60-90% of cases. Rezūm®, AquaBeam®, and UroLift® enable preservation of ejaculation in almost 100%; data on PAE with this respect are more controversial. For patients with a small prostate and significant post void residual, a thorough preoperative work-up, including urodynamics and bladder/detrusor wall thickness measurement, is of great importance. Desobstructive surgery provides satisfactory short- and midterm outcome, yet the long-term outcome is disappointing and remains to be determined in greater detail. The broad spectrum of therapeutic options enables today an individualized minimally invasive or surgical management of BPH considering patient wishes, anatomical factors or urodynamic factors. The time of a "one therapy fits all" strategy is definitely history.

Detrusor underactivity versus bladder outlet obstruction clinical and urodynamic factors

Objectives:

Methods:

Results:

Conclusion:

Comparison of Two Numerical Parameters to Assess Detrusor Contractility in Prognosing Short-Term Outcome after Transurethral Resection of the Prostate

OBJECTIVE

To investigate and compare the influence of two numerical detrusor contractility parameters, the bladder contractility index (BCI) and the maximum Watts factor (WFmax), on transurethral resection of the prostate (TURP) outcome.

METHODS

A retrospective study was conducted on 236 patients who had undergone urodynamic assessment preoperatively and TURP for benign prostatic obstruction. They were evaluated by International Prostate Symptom Score (IPSS) and uroflowmetry preoperatively and 3 months postoperatively. Related criteria were established to determine the overall efficacy of TURP. Logistic regression analysis and receiver operating characteristic curves were made to investigate the influence of the BCI and WFmax on TURP efficacy.

RESULTS

Among the 236 patients, 195 treatments were effective and 41 ineffective. Multivariate analysis showed that both the BCI (OR 1.038) and the WFmax (OR 1.291) could influence TURP efficacy. For predicting TURP efficacy, the optimal cut-off values of the BCI and WFmax were 98.7 and 10.27 W/m2, respectively. The AUC, sensitivity and specificity of the BCI were 0.722, 78.5% and 61.0%; those of the WFmax were 0.761, 73.9% and 73.2%, with no significant difference (p > 0.05).

CONCLUSIONS

To some extent, the BCI and the WFmax can predict TURP efficacy equally well. A discrimination level of 10.27 W/m2 may be a threshold value for detrusor underactivity (DU); as regards the BCI, the current threshold value is appropriate to diagnose DU.

Change of Detrusor Contractility in Patients with and without Bladder Outlet Obstruction at Ten or More Years of follow-up

To analyze the change of detrusor contractility by investigating urodynamic characteristics with long term follow-up. This study retrospectively reviewed 166 lower urinary tract symptoms patients without bladder outlet obstruction (BOO) and 63 patients with BOO who underwent repeated urodynamic studies at the first time and more than 10 years later. The urodynamic parameters, bladder contractility index (BCI), and BOO index (BOOI) were compared before and after. As time goes by, detrusor pressure at maximum flow rate (PdetQmax) significantly decreased and post-void residual (PVR) volume significantly increased in both men and women. Full sensation, urge sensation, voided volume, and BCI significantly decreased. We also compared men with and without BOO, PdetQmax, maximum flow rate (Qmax), voided volume, and BCI all significantly decreased in both groups without difference. PVR increased greater in men with BOO after >10 years significantly (p = 0.036). Women with detrusor overactivity (DO) under antimuscarinic showed no significant BCI change compared to patients without DO (p = 0.228). Detrusor contractility decreases in men and women after >10 years of follow-up. However, this finding suggests that patients with BOO or DO under adequate medical treatment, detrusor contractility is not aggravated over 10 or more years of follow-up.

The mechanical stop test and isovolumetric detrusor contractile reserve are associated with immediate spontaneous voiding after transurethral resection of prostate

PURPOSE

To identify urodynamic factors associated with the mechanical stop test and immediate spontaneous voiding following transurethral resection of prostate (TURP).

METHODS

We identified 90 men who underwent TURP over a 12-month period. Forty-three (mean age 68 years) underwent urodynamic evaluation prior to TURP. Isovolumetric detrusor contractile pressure (P_iso) was obtained using the mechanical stop test during the voiding phase, and used to calculate detrusor contractile reserve (P_res = P_iso - P_det@Q_max). Primary outcome was spontaneous voiding after TURP.

RESULTS

Preoperative catheter-free spontaneous voiding was present in 63% of men (27/43) with a urodynamic (mean ± SD): Q_max 6.2 ± 2.7 mL/s, P_det@Q_max 102 ± 47 cmH₂O, P_iso 124 ± 49 cmH₂O, P_res 22 ± 16 cmH₂O, bladder outlet obstruction index (BOOI) 90 ± 49, and bladder contractility index (BCI) 132 ± 44. The remaining 16 catheter-dependent men demonstrated a urodynamic (mean ± SD): Q_max 3.6 ± 3.3 mL/s, P_det@Q_max 87 ± 38 cmH₂O, P_iso 99 ± 51 cmH₂O, P_res 10 ± 18 cmH₂O, BOOI 82 ± 36, and BCI 106 ± 48. Following TURP, 67% of men voided spontaneously with their first void trial, and in receiver operator analysis of urodynamic measures (P_det@Q_max, P_iso, P_res, BOOI and BCI), only P_res was significantly associated with immediate spontaneous voiding after TURP (threshold P_res ≥ 9 cmH₂O, AUC = 0.681, p = 0.035).

CONCLUSIONS

In men who underwent TURP, a P_res ≥ 9 cmH₂O was associated with immediate spontaneous voiding and may be easily incorporated into the postoperative pathway.

The International Continence Society (ICS) report on the terminology for adult male lower urinary tract and pelvic floor symptoms and dysfunction

INTRODUCTION

In the development of terminology of the lower urinary tract, due to its increasing complexity, the terminology for male lower urinary tract and pelvic floor symptoms and dysfunction needs to be updated using a male-specific approach and via a clinically-based consensus report.

METHODS

This report combines the input of members of the Standardisation Committee of the International Continence Society (ICS) in a Working Group with recognized experts in the field, assisted by many external referees. Appropriate core clinical categories and a subclassification were developed to give a numeric coding to each definition. An extensive process of 22 rounds of internal and external review was developed to exhaustively examine each definition, with decision-making by collective opinion (consensus).

RESULTS

A Terminology Report for male lower urinary tract and pelvic floor symptoms and dysfunction, encompassing around 390 separate definitions/descriptors, has been developed. It is clinically-based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in male lower urinary tract and pelvic floor dysfunction. Male-specific imaging (ultrasound, radiology, CT, and MRI) has been a major addition whilst appropriate figures have been included to supplement and help clarify the text.

CONCLUSIONS

A consensus-based Terminology Report for male lower urinary tract and pelvic floor symptoms and dysfunction has been produced aimed at being a significant aid to clinical practice and a stimulus for research.

Comparative study of the maximum Watts factor and Schafer contractility grade, bladder contractility index in male patients with lower urinary tract symptoms

To investigate whether the maximum Watts factor (WF) is 1 parameter of describing detrusor contraction in male patients with lower urinary tract symptoms (LUTS).We retrospectively reviewed urodynamic data of male subjects with LUTS. Data on age, maximum flow rate (Qmax), post-void residual (PVR), detrusor pressure at maximum flow rate (PdetQmax), maximum Watts factor (WFmax), and Schafer contractility grades were collected. First, all patients were divided into 6 groups according to Schafer contractility grade. The urodynamic parameters include WFmax and bladder contractility index (BCI) were compared and analyzed among the 6 groups by using Kruskal-Wallis test statistically. The box plot of Schafer contractility grade with WFmax or BCI were plotted and analyzed. Second, the correlation scatter diagram between WFmax and BCI was plotted and analyzed. Spearman's correlation test was performed. Third, we drew the Receiver Operating Characteristic (ROC) curve and confirmed the area under the curve, the Optimal Operating Point (OOP) and corresponding sensitivity and specificity for WFmax by the reference standard of Schafer contractility grade and BCI respectively.A total of 455 men were included. The mean age of patients was 57 ± 17.9 years, ranging from 18 to 87 years. Median of WFmax increased from 5.8 W/m in very week (VW) group to 19.5 W/m in strong (ST) group, while BCI rose from 70 to 170. The box plot of Schafer contractility grade with WFmax or BCI showed that both WFmax and BCI were positively correlated with Schafer contractility grade. Kruskal-Wallis test among the 6 groups showed statistically significant difference (P <.001). The correlation scatter diagram showed that WFmax increased significantly with BCI (), the linear regression equation being Y = 3.33 + 0.07X, R2 = 0.298. Spearman's correlation test revealed that WFmax and BCI were positively correlated, with the correlation coefficient being 0.616 (P <.001). The WFmax area under ROC curve by Schafer contractility grade was 0.894 and WFmax OOP was interpreted at 11.1 W/m. In addition, the area under ROC curve by BCI was 0.802 and WFmax OOP was interpreted at 9.8 W/m.Our findings suggestted that WFmax was a good parameter of evaluating detrusor contraction as well as Schafer contractility grade and BCI, which should be widely used in clinical.

Detrusor Underactivity and the Underactive Bladder: A Systematic Review of Preclinical and Clinical Studies

CONTEXT

Detrusor underactivity (DUA) is a common but relatively under-researched bladder dysfunction. Underactive bladder (UAB) is the symptom-based correlate of DUA. Recently, there has been renewed interest in this topic.

OBJECTIVE

To systematically review and summarise the most recent literature and discuss this in the context of what is already known.

EVIDENCE ACQUISITION

A systematic review of the literature was performed in December 2017 using Medline and Scopus databases. Separate searches of each database used a complex search strategy including "free text" protocols. Search terms included "underactive bladder", "detrusor underactivity", "acontractile bladder", "detrusor failure", "detrusor areflexia", "atonic bladder", "chronic retention", and "impaired bladder contractility".

EVIDENCE SYNTHESIS

The initial search retrieved a total of 1690 studies; of these 44 were included in the final analyses.

CONCLUSIONS

Although there has been an expansion in the literature concerning all aspects of DUA and UAB, knowledge on its epidemiology and aetiopathogenesis is still lacking; there remains a need to develop accurate reproducible diagnostic criteria and effective treatments, in particular drug therapies.

PATIENT SUMMARY

Recently, there has been renewed interest in underactive bladder with expanding research in this area. The lack of simple, reproducible, noninvasive diagnostic criteria has precluded an accurate estimation of the magnitude of the problem. Recent studies have highlighted the potential role of impaired bladder blood supply in causing bladder underactivity.

Recent research on the role of urodynamic study in the diagnosis and treatment of male lower urinary tract symptoms and urinary incontinence

Although evidence shows that urodynamic study may not improve outcomes, it can be used to evaluate men with lower urinary tract symptoms (LUTSs) which have not been adequately delineated and treated. In young men with LUTS not responding to treatment based on clinical examination, or elderly men with LUTS and incontinence, a complete urodynamic evaluation is mandatory to understand the pathophysiology underlying LUTS, such as bladder outlet obstruction (BOO), detrusor overactivity, and detrusor underactivity. Preoperative urodynamic study-proven BOO is a predictor of a successful surgical outcome. An urodynamic study should be performed when patients with LUTS are planning to undergo surgical treatment for benign prostatic obstruction.

Non-neurogenic Chronic Urinary Retention: What Are We Treating?

PURPOSE OF REVIEW

This review examines current terminology used to define non-neurogenic chronic urinary retention (CUR), describes the pathophysiology of urinary retention, and highlights contemporary diagnostic and treatment algorithms.

RECENT FINDINGS

There is no standardized definition for the condition, but volumes >300 ml are commonly used to describe CUR. It is a clinical diagnosis which does not require urodynamics. Pathophysiologic causes of CUR be from myogenic, neurogenic, bladder outlet obstruction, or a combination of these sources. Treatment algorithms recommend stratifying patients with chronic urinary retention by risk and by symptoms before initiating treatment. Common CUR outcome endpoints need to be better utilized so that treatment modalities can be compared. Non-neurogenic CUR is a heterogeneous condition that has multiple definitions, underlying physiologies, and possible endpoints. Standardization is needed to better understand and treat CUR.

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.

Recommendations for future development of contractility and obstruction nomograms for women. ICI-RS 2014

AIMS

At present, existing bladder outlet obstruction (BOO) nomograms for women are still not universally accepted. Moreover, only limited information is available regarding bladder contractility in women. The aim is to present the discussions and recommendations from the think tank session "Can we construct and validate contractility and obstruction nomograms for women?" held at the 2014 International Consultation on Incontinence-Research Society (ICI-RS) meeting in Bristol, UK.

METHODS

An overview of clinical significance, bladder mechanics and modelling, lack of existing nomograms for women, and development of new nomograms were presented and discussed in a multidisciplinary think tank session. This think tank session was based on a collaboration between physicians, engineers, and researchers and consensus was achieved on future research initiatives.

RESULTS AND CONCLUSIONS

Based on the think tank discussion, the ICI-RS panel put forward the following recommendations: the need to acquire normative age-matched data in women to define "normal" and "pathological" values of urodynamic parameters; the inclusion of additional clinical data in new nomograms and the use of this extra dimension to develop clinically applicable nomograms for female BOO and contractility; and finally, the need to take into account the variability of BOO in women when developing female bladder contractility nomograms.

Ultrasound detrusor wall thickness measurement in combination with bladder capacity can safely detect detrusor underactivity in adult men

PURPOSE

Detrusor underactivity (DU) has lately gained increasing interest because this bladder condition is an important cause of post-void residual urine and lower urinary tract symptoms (LUTS) in adult men. Until now, DU can only be diagnosed by pressure-flow measurement. Therefore, the aim of this study was to search for noninvasive tests which can safely predict DU in adult men.

METHODS

Unselected, treatment-naïve male patients aged ≥40 years with uncomplicated, non-neurogenic LUTS were prospectively evaluated. All men received-after standard assessment of male LUTS-ultrasound detrusor wall thickness (DWT) measurements at a bladder filling ≥250 ml and computer urodynamic investigation. DU was defined as incomplete bladder emptying (>30 ml) in the absence of bladder outlet obstruction or dysfunctional voiding. Classification and regression tree (CART) analysis was used to determine parameters and threshold values for DU.

RESULTS

The study population consisted of 143 consecutive men with medians of 62 years, IPSS 16, and prostate volume 35 ml. In total, 33 patients (23.1 %) had DU. CART analysis showed that all men with DWT ≤ 1.23 mm plus bladder capacity >445 ml had DU. This multivariate model has a sensitivity of 42 %, specificity of 100 %, positive predictive value of 100 %, and negative predictive value of 85 %.

CONCLUSIONS

This study showed that all men with ultrasound DWT ≤ 1.23 mm + bladder capacity >445 ml have DU. Combination of these two tests could help physicians to diagnose DU noninvasively in clinical practice. A prospective independent study should confirm these results.

Urodynamic Features and Significant Predictors of Bladder Outlet Obstruction in Patients With Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia and Small Prostate Volume

OBJECTIVE

To investigate the clinical and urodynamic features of patients with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH) according to their prostate size.

MATERIALS AND METHODS

We analyzed 2039 LUTS/BPH patients who underwent urodynamic study between October 2004 and August 2013. We divided the patients into three groups according to their prostate size: small (≤30 mL), moderately enlarged (31-80 mL), and large prostate (≥81 mL) groups. We compared the groups regarding age, International Prostatic Symptom Score, maximal flow rate (Qmax), postvoided residual (PVR), serum prostate-specific antigen, prostate volume measured by ultrasonography, and urodynamic findings.

RESULTS

Patients with a small prostate had better urodynamic outcomes than those with larger prostates in overall population. Although the total prostate volume significantly correlated with the bladder outlet obstruction (BOO) index (r  =  0.51), BOO patients with a small prostate had similar Qmax, higher PVR, and lower voiding efficiency, compared to those with larger prostates. Moreover, urodynamic parameters indicating bladder abnormalities, including low compliance and involuntary detrusor contraction positivity, were similar among the groups in BOO patients. A higher proportion of detrusor underactivity was also observed in the small prostate group in BOO patients. Finally, when adjusting for potential confounding variables, we identified serum prostate-specific antigen levels (odds ratio, 1.34) and Qmax (odds ratio, 0.77) as significant predictors for BOO in LUTS/BPH patients with a small prostate.

CONCLUSION

BOO patients with a small prostate showed higher PVR and poor voiding efficiency, as well as similar urodynamic bladder abnormalities, compared to those with moderately enlarged and large prostates.