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The role of prostatic apex shape in voiding symptoms and urine flow: an exploratory and confirmatory study

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Lower urinary tract symptoms in men have previously been attributed to obstruction from an enlarged prostate. However, several factors in addition to prostate volume have been identified as impacting urine flow. Prostatic apex shape is one factor that has not been evaluated. This study evaluates the relationship between prostatic apex shape and voiding symptoms and urine flow.


A retrospective, exploratory data review was conducted for 806 healthy men who underwent routine transrectal ultrasonography at our hospital, and data for 329 patients with uroflowmetric measurements were reviewed for the confirmatory study. Patients were categorized into four groups according to the prostatic apex shape on midsagittal ultrasonography. The association between prostatic apex shape and voiding symptoms was investigated. International Prostate Symptom Score (IPSS) and uroflowmetry were measured, and the associations between IPSS, uroflowmetry, and prostatic apex shape were analyzed.


Patients in group 4 (356/806, 44.2%), whose prostatic apex did not overlap the membranous urethra anteriorly or posteriorly, had a significantly lower incidence of moderate and severe lower urinary tract symptoms compared to other groups. There was a significant relationship between prostatic apex shape and total International Prostate Symptom Score. Patients in group 3, whose prostatic apex overlapped posteriorly with the membranous urethra, had lower maximum flow rates on uroflowmetry. There were significant correlations between the maximum flow rate and independent factors including age, intravesicle prostatic protrusion, and prostatic apex shape.


Prostatic apex shape is an independent risk factor for voiding symptom severity and low maximum flow rate.

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  1. Nitti VW (2005) Pressure flow urodynamic studies: the gold standard for diagnosing bladder outlet obstruction. Rev Urol 7(Suppl 6):S14

    PubMed  PubMed Central  Google Scholar 

  2. Nitti VW, Kim Y, Combs AJ (1994) Correlation of the AUA symptom index with urodynamics in patients with suspected benign prostatic hyperplasia. Neurourol Urodyn 13:521–527

    Article  CAS  PubMed  Google Scholar 

  3. van Venrooij GE, Boon TA (1996) The value of symptom score, quality of life score, maximal urinary flow rate, residual volume and prostate size for the diagnosis of obstructive benign prostatic hyperplasia: a urodynamic analysis. J Urol 155:2014–2018

    Article  PubMed  Google Scholar 

  4. Sirls LT, Kirkemo AK, Jay J (1996) Lack of correlation of the American Urological Association Symptom 7 Index with urodynamic bladder outlet obstruction. Neurourol Urodyn 15:447–457

    Article  CAS  PubMed  Google Scholar 

  5. Chia SJ, Heng CT, Chan SP, Foo KT (2003) Correlation of intravesical prostatic protrusion with bladder outlet obstruction. BJU Int 91:371–374

    Article  CAS  PubMed  Google Scholar 

  6. Cho KS, Kim JH, Kim DJ, Choi YD, Kim JH, Hong SJ (2008) Relationship between prostatic urethral angle and urinary flow rate: its implication in benign prostatic hyperplasia pathogenesis. Urology 71:858–862

    Article  PubMed  Google Scholar 

  7. Myers RP (2001) Practical surgical anatomy for radical prostatectomy. Urol Clin N Am 28:473–490

    Article  CAS  Google Scholar 

  8. Lee SE, Byun SS, Lee HJ, Song SH, Chang IH, Kim YJ, Gill MC, Hong SK (2006) Impact of variations in prostatic apex shape on early recovery of urinary continence after radical retropubic prostatectomy. Urology 68:137–141

    Article  PubMed  Google Scholar 

  9. Barry MJ, Fowler FJ Jr, O’Leary MP, Bruskewitz RC, Holtgrewe HL, Mebust WK, Cockett AT, Measurement Committee of the American Urological Association (2017) The American Urological Association Symptom Index for benign prostatic hyperplasia. J Urol 197:S189–S197

    Article  PubMed  Google Scholar 

  10. Ito K, Takashima Y, Akamatsu S, Terada N, Kobayashi T, Yamasaki T, Inoue T, Kamba T, Ogawa O, Negoro H (2018) Intravesical prostatic protrusion is not always the same shape: evaluation by preoperative cystoscopy and outcome in HoLEP. Neurourol Urodyn 37:2160–2166

    Article  PubMed  Google Scholar 

  11. Witjes WP, Aarnink RG, Ezz-el-Din K, Wijkstra H, Debruyne FM, De La Rosette JJ (1997) The correlation between prostate volume, transition zone volume, transition zone index and clinical and urodynamic investigations in patients with lower urinary tract symptoms. Br J Urol 80:84–90

    Article  CAS  PubMed  Google Scholar 

  12. Zheng J, Pan J, Qin Y, Huang J, Luo Y, Gao X, Zhou X (2015) Role for intravesical prostatic protrusion in lower urinary tract symptom: a fluid structural interaction analysis study. BMC Urol 15:86

    Article  PubMed  PubMed Central  Google Scholar 

  13. Dutkiewicz SA, Wroblewski M (2012) Comparison of treatment results between holmium laser endourethrotomy and optical internal urethrotomy for urethral stricture. Int Urol Nephrol 44:717–724

    Article  PubMed  Google Scholar 

  14. Zheng J, Xu K, Sun Y, Sun C, Ding Q, Fang Z (2013) Evaluation of urodynamic findings before and after mid-urethral tape sling operation for female stress urinary incontinence. J Minim Invasive Gynecol 20:482–486

    Article  PubMed  Google Scholar 

  15. Kaplan SA, Te AE, Pressler LB, Olsson CA (1995) Transition zone index as a method of assessing benign prostatic hyperplasia: correlation with symptoms, urine flow and detrusor pressure. J Urol 154:1764–1769

    Article  CAS  PubMed  Google Scholar 

  16. Lepor H, Nieder A, Feser J, O’Connell C, Dixon C (1997) Total prostate and transition zone volumes, and transition zone index are poorly correlated with objective measures of clinical benign prostatic hyperplasia. J Urol 158:85–88

    Article  CAS  PubMed  Google Scholar 

  17. Barry MJ, Cockett AT, Holtgrewe HL, McConnell JD, Sihelnik SA, Winfield HN (1993) Relationship of symptoms of prostatism to commonly used physiological and anatomical measures of the severity of benign prostatic hyperplasia. J Urol 150:351–358

    Article  CAS  PubMed  Google Scholar 

  18. Ryall RL, Marshall VR (1982) Normal peak urinary flow rates obtained from small voided volumes can provide a reliable assessment of bladder function. J Urol 127:484–488

    Article  CAS  PubMed  Google Scholar 

  19. Marshall VR, Ryall RL, Austin ML, Sinclair GR (1983) The use of urinary flow rates obtained from voided volumes less than 150 ml in the assessment of voiding ability. Br J Urol 55:28–33

    Article  CAS  PubMed  Google Scholar 

  20. Kim KJ, Jurnalov CD, Lightner DJ, Webb MJ, Lee RA, An KN (1998) Principles of urodynamics pressure measurement and its implication to female continence function. J Biomech 31:861–865

    Article  CAS  PubMed  Google Scholar 

  21. Barnea O, Gillon G (2001) Model-based estimation of male urethral resistance and elasticity using pressure-flow data. Comput Biol Med 31:27–40

    Article  CAS  PubMed  Google Scholar 

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The authors would like to thank Dong-Su Jang, MFA (Medical Illustrator), for his help with the illustrations.

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Authors and Affiliations



JSP: project development, data analysis, manuscript writing/editing. DL: data collection. KCK: project development, data analysis. BHC: project development, data analysis. KSL: project development, data collection, data analysis, manuscript editing.

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Correspondence to Kwang Suk Lee.

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All of the authors declare that they have no conflicts of interest.

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All procedures performed in the study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee, and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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Informed consent was not required for the purposes of this study, as it was based upon retrospective anonymous patient data and did not involve patient intervention or the use of human tissue samples.

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Park, J.S., Lee, D., Koo, K.C. et al. The role of prostatic apex shape in voiding symptoms and urine flow: an exploratory and confirmatory study. World J Urol 38, 1275–1282 (2020).

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