International Prostatic Symptom Score — Voiding/Storage Subscore Ratio in Association with Total Prostatic Volume and Maximum Flow Rate Is Diagnostic of Bladder Outlet-Related Lower Urinary Tract Dysfunction in Men with Lower Urinary Tract Symptoms

Kuo H-C (2013) International Prostatic Symptom Score - Voiding/Storage Subscore Ratio in Association with Total Prostatic Volume and Maximum Flow Rate Is Diagnostic of Bladder Outlet-Related Lower Urinary Tract Dysfunction in Men with Lower Urinary Tract Symptoms. PLoS ONE 8(3): e59176. doi:10.1371/journal.pone.0059176 International Prostatic Symptom Score - Voiding/ Storage Subscore Ratio in Association with Total Prostatic Volume and Maximum Flow Rate Is Diagnostic of Bladder Outlet-Related Lower Urinary Tract Dysfunction in Men with Lower Urinary Tract Symptoms Yuan-Hong Jiang 0 Victor Chia-Hsiang Lin 0 Chun-Hou Liao 0 Hann-Chorng Kuo 0 Utpal Sen, University of Louisville, United States of America 0 1 Department of Urology, Buddhist Tzu Chi General Hospital and Tzu Chi University , Hualien, Taiwan , 2 Department of Urology, E-Da Hospital , Kaohsiung, Taiwan , 3 Department of Urology, Cardinal Tien Hospital and Fu-Jen Catholic University , New Taipei , Taiwan Objectives: The aim of this study was to investigate the predictive values of the total International Prostate Symptom Score (IPSS-T) and voiding to storage subscore ratio (IPSS-V/S) in association with total prostate volume (TPV) and maximum urinary flow rate (Qmax) in the diagnosis of bladder outlet-related lower urinary tract dysfunction (LUTD) in men with lower urinary tract symptoms (LUTS). Methods: A total of 298 men with LUTS were enrolled. Video-urodynamic studies were used to determine the causes of LUTS. Differences in IPSS-T, IPSS-V/S ratio, TPV and Qmax between patients with bladder outlet-related LUTD and bladderrelated LUTD were analyzed. The positive and negative predictive values (PPV and NPV) for bladder outlet-related LUTD were calculated using these parameters. Results: Of the 298 men, bladder outlet-related LUTD was diagnosed in 167 (56%). We found that IPSS-V/S ratio was significantly higher among those patients with bladder outlet-related LUTD than patients with bladder-related LUTD (2.2862.25 vs. 0.9060.88, p,0.001). TPV was similar between the two groups; however, in contrast to patients with bladderrelated LUTD, patients with bladder outlet-related LUTD had higher detrusor voiding pressure, lower Qmax values, and greater postvoid residual volumes. The combination of TPV 30 ml and Qmax 10 ml/sec had a PPV of 68.8% and a NPV of 53.5% for bladder outlet-related LUTD. When IPSS-T 12 or IPSS-T 15 was considered as an additional criterion, PPV increased to 75.0% and 78.5%, respectively, and the NPV decreased to 50.9% and 50.2%, respectively. When IPSS-V/S.1 or .2 was factored into the equation instead of IPSS-T, PPV were 91.4% and 97.3%, respectively, and NPV were 54.8% and 49.8%, respectively. - Conclusions: Combination of IPSS-T with TPV and Qmax increases the PPV of bladder outlet-related LUTD. Furthermore, including IPSS-V/S.1 or .2 into the equation results in a higher PPV than IPSS-T. IPSS-V/S.1 is a stronger predictor of bladder outlet-related LUTD than IPSS-T. . These authors contributed equally to this work. Lower urinary tract symptoms (LUTS), including voiding, storage, and post-micturition symptoms, are highly prevalent in men [1]. LUTS can result from a complex interplay of pathophysiologic features that can include bladder dysfunction and bladder outlet dysfunction such as benign prostatic obstruction (BPO), bladder neck dysfunction (BND) or poor relaxation of the urethral sphincter (PRES) [2].Urodynamically proven bladder outlet obstruction (BOO) is found in 4853% of men with LUTS, although only 29.4% of them show evidence of BPO [2,3]. Treatment of LUTS in men depends on the etiology of the symptoms. Traditionally, LUTS in men is usually attributed to BPO and is treated with a-adrenoceptor antagonists [4].However, men who receive treatment for prostate conditions may have persistent storage symptoms [5,6]. Studies on LUTS in men have recently shifted from the prostate to the bladder as the source of LUTS and also as a therapeutic target [4]. Current guidelines also suggest that antimuscarinic monotherapy can be used for men with storage LUTS, those without voiding LUTS, and those without voiding BOO [7,8,9]. Determining the presence and the degree of BOO in men with LUTS can be difficult based on clinical symptoms alone but is important [2]. A variety of non-invasive urodynamic and nonurodynamic methods have been used to evaluate LUTS. Symptom score, urine flow rate and prostate volume are poorly predictive of BOO when used alone, and elevated postvoid residual (PVR) volume is only weakly associated with BOO [4,10]. However, combining certain threshold values of the total International Prostate Symptom Score (IPSS-T) with maximum urinary flow rate (Qmax) and total prostate volume (TPV) may be useful for predicting BOO; however, studies have shown that this approach is not very sensitivity [10]. The IPSS consists of seven questions that deal with voiding symptoms (incomplete emptying, intermittency, weak stream and straining to void) and storage symptoms (frequency, urgency and nocturia). We previously reported that measuring IPSS subscores and calculating the IPSS voiding-to-storage subscore ratio (IPSSV/S) is a simple and useful method for differentiating between failure to voiding lower urinary tract dysfunction (LUTD) and failure to storage LUTD [11]. The IPSS-V/S can also serve as a guide for initial treatment of male patients with LUTS. In this study, we investigated whether IPSS-T or IPSS-V/S in association with TPV and Qmax could increase the diagnostic accuracy of bladder outlet-related LUTD in men with LUTS. Materials and Methods A total of 298 men with LUTS were enrolled in the study from January 2005 to July 2010 at a tertiary teaching hospital. Men with LUTS and without documented genitourinary cancer, acute or chronic urinary retention, diabetic cystopathy, frank neuropathy, detrusor areflexia, or active urinary tract infection were included. The IPSS-voiding (IPSS-V) and IPSS-storage (IPSS-S) subscores were recorded separately by the patients using a validated Chinese version of IPSS, and the IPSS-V/S was calculated. TPV and transitional zone index (TZI) in transrectal ultrasound of the prostate, Qmax, and PVR were also evaluated. All the enrolled patients were nave to treatment, and the causes of LUTS were determined by videourodynamic studies (VUDS). The presence of detrusor overactivity (DO), cystometric bladder capacity (CBC), maximal detrusor pressure at Qmax (Pdet) and PVR were also recorded. VUDS were performed with a standard procedure at a filling rate of 30 ml/min with patients in a standing position and were repeated at least two times to obtain a reproducible pressure-flow tracing. The procedures and the terminology used in this study were in accordance with the recommendations of the International Continence Society unless specified otherwise [12]. Patients without an uninhibited detrusor contraction who had a strong desire to void at a (...truncated)