Current consensus and controversy on the diagnosis of male lower urinary tract symptoms/benign prostatic hyperplasia.

Tzu Chi Medical Journal 2017; 29(1): 6-11 Review Article Current consensus and controversy on the diagnosis of male lower urinary tract symptoms/benign prostatic hyperplasia Cheng-Ling Lee, Hann-Chorng Kuo* Department of Urology, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan Abstract Received : 09-12-2016 Revised : 12-12-2016 Accepted : 16-12-2016 Keywords: Lower urinary tract symptoms, Medical treatment, Overactive bladder, Quality of life, Surgery Traditionally, male lower urinary tract symptoms (LUTS) have been considered a synonym for benign prostate hyperplasia (BPH) because most male LUTS develops in aging men. Medical treatment should be the first-line treatment for BPH and surgical intervention should be performed when there are complications or LUTS refractory to medical treatment. Recent investigations have revealed that bladder dysfunction and bladder outlet dysfunction contribute equally to male LUTS. In the diagnosis of LUTS suggestive of BPH (LUTS/BPH), the following questions should be considered: Is there an obstruction? Are the LUTS caused by an enlarged prostate? What are the appropriate tools to diagnose an obstructive BPH? Should patients with LUTS be treated before bladder outlet obstruction is confirmed? This article discusses the current consensus and controversies in the diagnosis of LUTS/BPH. Benign prostate hyperplasia – current concept of lower urinary tract symptoms/benign prostate hyperplasia L ower urinary tract symptoms (LUTS) are highly prevalent in men and the incidence increases with age [1]. LUTS is usually considered a synonym for benign prostatic hyperplasia (BPH). However, only 25% to 50% of men with BPH have LUTS, and urodynamically-proven bladder outlet obstruction (BOO) is only seen in 50% of men with LUTS [2]. Clinically, the diagnosis of BPH and BOO is usually made based on a total prostate volume (TPV) >40 mL, and a maximum flow rate (Qmax) <10 mL/s, in combination with a high International Prostate Symptom Score (IPSS) [3]. Many clinical studies have demonstrated that LUTS have poor diagnostic specificity for BOO and the symptoms of some patients with LUTS/BPH do not improve after transurethral resection of the prostate (TURP) [4]. Although an enlarged prostate might not indicate the presence of BOO, the mean TPV of patients with Access this article online Quick Response Code: Website: www.tcmjmed.com DOI: 10.4103/tcmj.tcmj_3_17 6 BOO is significantly greater than that of patients without BOO [5]. In addition, patients with LUTS/BPH and a Qmax of <10 mL/s have a greater improvement in the Qmax after TURP compared with those with a Qmax >10 mL/s. Patients without urodynamic evidence of BOO may have a poor surgical outcome after TURP [6]. In one study, patients with persistent LUTS after TURP were found to have a small TPV at the time of surgery, suggesting that a non-BPH etiology might account for their LUTS [7]. Therefore, diagnosis of clinical BPH should be undertaken carefully, especially when an invasive procedure such as TURP is going to be performed. The differential diagnosis for non-BPH lower urinary tract dysfunction (LUTD) is important in the management of LUTS/BPH. *Address for correspondence: Dr. Hann-Chorng Kuo, Department of Urology, Buddhist Tzu Chi General Hospital, 707, Section 3, Chung-Yang Road, Hualien, Taiwan. E-mail: This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms. For reprints contact: How to cite this article: Lee CL, Kuo HC. Current consensus and controversy on the diagnosis of male lower urinary tract symptoms/ benign prostatic hyperplasia. Tzu Chi Med J 2017;29:6-11. © 2017 Tzu Chi Medical Journal | Published by Wolters Kluwer - Medknow Lee and Kuo / Tzu Chi Medical Journal 2017; 29(1): 6-11 Differential diagnosis of lower urinary tract symptoms based on the international prostate symptom score voiding to storage ratio The focus on LUTS has recently shifted from the prostate to the bladder [8]. Several investigations suggest that not all male LUTS are associated with prostate pathology or BOO and bladder dysfunction plays a role in the pathogenesis. However, it is difficult to distinguish the causes of male LUTS based on clinical symptoms, and a subset of patients receiving treatment for prostatic conditions may have residual overactive bladder (OAB) symptoms [7,9,10]. Although urodynamic pressure flow study is helpful in the differential diagnosis, the equipment is not available in every clinic. The pathophysiology of male LUTS could be bladder dysfunction, (including hypersensitive bladder, detrusor overactivity [DO], detrusor hyperactivity and inadequate contractility [DHIC]), BOO (including bladder neck dysfunction [BND], prostatic obstruction, urethral stricture, poor relaxation of the urethral sphincter), or a combination of these etiologies. It has been estimated that only 48%–53% of men with LUTS have urodynamically-proven BOO due to BPH or other bladder outlet dysfunctions [2]. In addition, approximately 50%–75% of patients with BOO have OAB symptoms [11,12], and 46 to 66% of patients with BPO on urodynamics have DO [13,14]. The practice guidelines of the both the European Association of Urology and the American Urological Association (AUA) recommend that evaluating symptom severity with a symptom score is an important part of the assessment of male LUTS [15,16]. The IPSS and American Urological Association Symptom Index (AUA-SI) have been widely used for decades in many languages to evaluate the severity of LUTS/ BPH, and have been applied to other conditions causing LUTS for comparison of treatment outcomes. Measuring the IPSS-storage (IPSS-S) and IPS-voiding (IPSS-V) subscores separately and using the IPSS-V/S ratio can help differentiate bladder- and urethra-related conditions [17]. We have previously constructed an IPSS voiding to storage (IPSS-V/S) ratio for differential diagnosis of bladder and bladder outlet dysfunction. An IPSS-V/S <1.0 was noted in 80% of patients with bladder-related LUTS and an IPSS-V/S >1.0 was seen in 76% of patients with BPH-BOO and non-BPH voiding dysfunction. Alpha-blockers and 5-alpha-reductase inhibitors (5ARIs) are effective in the treatment of men with BOO due to BPH or non-BPH voiding dysfunction. These agents may not be effective treatment for storage symptoms [9]. Antimuscarinic or anticholinergic agents are the firstline treatment for patients with OAB [18]. According to the initial differential diagnosis and medication given, 75% of patients with bladder-related conditions (IPSS-V/S <1) and 80% of those with urethral-related conditions (IPSS-V/S >1) reported improved outcomes after medical treatment with antimuscarinic agents and alpha-blockers, (...truncated)