#18 – Benign Prostatic Hyperplasia



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Epidemiology

The prostate begins to enlarge in the 4th decade of life with a significant jump in the 6th decade of life.  Mean prostate weight in normal men < 30yo is around 20g and steadily increases after this.  Volume of the prostate also steadily increases after the 4th decade with symptoms typically starting to manifest once it reaches 30cc3.

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Up-To-Date. 2016


Risk Factors

  • Race
    • African Americans are at higher risk of requiring surgery
    • Asians have the lowest risk of requiring surgery
  • Prostatitis
    • Associated with increased risk of BPH

Pathogenesis of BPH

The main areas of the prostate that contribute to BPH are the periurethral (transitional zone) of the prostate and the hyperplastic nodules that develop are primarily comprised of stromal cells. The specific pathogenesis of BPH is still not completely understood and only 2 variables that have been identified as essential for BPH development: age and functioning Leydig Cells of the testes.  Androgens, estrogens, inflammation, genetics, and stromal growth factors have all been studied and have variable results.

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De Marzo. 2007.

 


Clinical Manifestations of BPH

The signs of symptoms of BPH can be broken down into 3 main categories:

  • Storage Symptoms
    • Urgency
    • Daytime frequency
    • Nocturia
    • Urgency incontinence
  • Voiding Symptoms
    • Slow, urinary stream
    • Splitting or spraying of the urinary stream
    • Intermittent urinary stream
    • Urinary hesitancy
    • Straining to void
    • Terminal dribbling
  • Post-micturition Symptoms
    • Incomplete bladder voiding
    • Post micturition dribble

Differential Diagnosis of BPH Symptoms

  • Urethral stricture or bladder neck contracture
    • Previous history of catheterization or instrumentation
    • Urethral trauma
    • Urethritis
  • Neurogenic bladder
    • Other signs and symptoms of neurologic disease
  • Bladder calculi
    • History of nephrolithiasis
  • Carcinoma of the bladder or prostate
    • Hematuria
    • Previous history of cancer
  • Urinary tract infection and prostatitis
    • Dysuria
    • Fever
  • Medications
    • Antcholinergics (decreases bladder function)
    • Sympathomimetics (increases outflow resistance)

International Prostate Symptom Score

The original AUA score was developed in 1992 and is used to assess the severity of symptoms of BPH, BUT NOT FOR DIFFERENTIAL DIAGNOSIS.  This is a seven-part questionnaire that evaluates symptoms on a 0-5 scale and then calculates the symptoms as mild, moderate, or severe.  An eight question was added to evaluate quality of life.

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International Prostate Symptom Score


Work-Up

  • Physical Exam
    • Digital Rectal Exam (DRE) should be performed to assess size, contour, regularity, and nodularity
    •  

  • Laboratory Testing
    • Urinalysis
      • Initial test to evaluate for microscopic hematuria and infection
    • Basic Metabolic Profile
      • BUN/Creatinine
        • Evaluate baseline renal function
      • Serum Prostate Specific Antigen (PSA)
        • PSA and prostate volume have a log-linear relationship
        • DOES NOT CORRELATE WITH CANCER
        • picture1
    • Uroflowmetry Study
      • Optional testing per AUA
      • Can evaluate maximal urinary flow rate
      • Patient voids with a full bladder (> 150cc)
      • < 15ml/s = outflow obstruction
      • picture1
      • picture1
    • Post-void Residual Urine Volume
      • Bladder scan is least invasive and most common
      • Normal men have < 12mL of residual urine post-void
      • picture1

Management

BPH can be managed by PCP if the patient has mild symptoms (low IPSS ≤ 7) and no complications.

Indications for urology referral are:

  • Symptoms with autonomic or peripheral neuropathy
  • Symptoms following invasive treatment of the urethra or prostate
  • Age < 45yo
  • Abnormality of prostate on DRE
  • Presence of hematuria in the absence of infection
  • Incontinence
  • Severe symptoms (IPSS ≥ 20)

Treatment

  • Medical
    • Alpha-1-adrenergic antagonists
      • Mechanism of Action
        • Relax smooth muscle of bladder neck, prostate capsule, and prostatic urethra
      • Side effects
        • Hypotension
      • Drugs
        • Terazosin (need to titrate)
        • Doxazosin (need to titrate)
        • Tamsulosin
    • 5-alpha-reductase inhibitors
      • Used if patients can’t tolerate hypotension of alpha-1-adrenergic antagonists
      • Need 6-12 months of treatment to see effects
      • Mechanism of Action
        • Reduce prostate size by preventing the conversion of testosterone to the more potent dihydrotestosterone
      • Drugs (no difference due to EPICS trial)
        • Finasteride
        • Dutasteride
    • Combination Alpha-1/5-Alpha Therapy
      • Indications
        • Severe symptoms (IPSS ≥ 20)
        • Large prostate (> 40cc)
        • Inadequate response to maximal monotherapy
      • Drugs
        • Doxazosin/finasteride
        • Tamsulosin/dutasteride
  • Surgical
    • Indications
      • Moderate/severe symptoms (IPSS ≥ 8) with high quality of life score (≥ 4)
      • Urinary retention refractory to medical therapy
      • Renal insufficiency secondary to BPH
      • Median lobe hypertrophy
    • Transurethral Procedures

Complications of Surgery

  • Bleeding
    • Higher in traditional TURP
  • Postprostatectomy Syndrome
    • Hyponatremia as a result of the systemic absorption of the hypotonic irrigation solution
  • Sexual Dysfunction
    • Ejaculatory Dysfunction
    • Erectile Dysfunction
  • Urethral Stricture
  • Urinary Incontinence

Cottage Physician

cottage-physician


References

  1. Berry SJ, Coffey DS, Walsh PC, Ewing LL. The development of human benign prostatic hyperplasia with age. The Journal of Urology. 1984;132(3):474-9. [pubmed]
  2. Bosch JL, Hop WC, Kirkels WJ, Schröder FH. Natural history of benign prostatic hyperplasia: appropriate case definition and estimation of its prevalence in the community. Urology. 1995;46(3 Suppl A):34-40. [pubmed]
  3. Sidney S, Quesenberry CP, Sadler MC, Guess HA, Lydick EG, Cattolica EV. Incidence of surgically treated benign prostatic hypertrophy and of prostate cancer among blacks and whites in a prepaid health care plan. American Journal of Epidemiology. 1991;134(8):825-9. [pubmed]
  4. Kang D, Andriole GL, Van De Vooren RC. Risk behaviours and benign prostatic hyperplasia. BJU International. 2004;93(9):1241-5. [pubmed]
  5. St Sauver JL, Jacobson DJ, McGree ME, Girman CJ, Lieber MM, Jacobsen SJ. Longitudinal association between prostatitis and development of benign prostatic hyperplasia. Urology. 2008;71(3):475-9; discussion 479. [pubmed]
  6. Rohr HP, Bartsch G. Human benign prostatic hyperplasia: a stromal disease? New perspectives by quantitative morphology. Urology. 1980;16(6):625-33. [pubmed]
  7. De Marzo AM, Platz EA, Sutcliffe S. Inflammation in prostate carcinogenesis. Nature Reviews. Cancer. 2007;7(4):256-69. [pubmed]
  8. Jones C, Hill J, Chapple C, . Management of lower urinary tract symptoms in men: summary of NICE guidance. BMJ (Clinical research ed.). 2010;340:c2354. [pubmed]
  9. Barry MJ, Fowler FJ, O’Leary MP. The American Urological Association symptom index for benign prostatic hyperplasia. The Measurement Committee of the American Urological Association. The Journal of Urology. 1992;148(5):1549-57; discussion 1564. [pubmed]
  10. McVary KT, Roehrborn CG, Avins AL. Update on AUA guideline on the management of benign prostatic hyperplasia. The Journal of Urology. 2011;185(5):1793-803. [pubmed]
  11. Roehrborn CG. The utility of serum prostatic-specific antigen in the management of men with benign prostatic hyperplasia. International Journal of Impotence Research. 2008;20 Suppl 3:S19-26. [pubmed]
  12. Oelke M, Bachmann A, Descazeaud A. EAU guidelines on the treatment and follow-up of non-neurogenic male lower urinary tract symptoms including benign prostatic obstruction. European Urology. 2013;64(1):118-40. [pubmed]
  13. Chapple CR. Pharmacological therapy of benign prostatic hyperplasia/lower urinary tract symptoms: an overview for the practicing clinician. BJU International. 2004;94(5):738-44. [pubmed]
  14. McVary KT, Roehrborn CG, Avins AL. Update on AUA guideline on the management of benign prostatic hyperplasia. The Journal of Urology. 2011;185(5):1793-803. [pubmed]
  15. Nickel JC, Gilling P, Tammela TL, Morrill B, Wilson TH, Rittmaster RS. Comparison of dutasteride and finasteride for treating benign prostatic hyperplasia: the Enlarged Prostate International Comparator Study (EPICS). BJU International. 2011;108(3):388-94. [pubmed]
  16. McConnell JD, Roehrborn CG, Bautista OM. The long-term effect of doxazosin, finasteride, and combination therapy on the clinical progression of benign prostatic hyperplasia. NEJM. 2003;349(25):2387-98. [pubmed]
  17. Roehrborn CG, Siami P, Barkin J. The effects of combination therapy with dutasteride and tamsulosin on clinical outcomes in men with symptomatic benign prostatic hyperplasia: 4-year results from the CombAT study. European Urology. 2010;57(1):123-31. [pubmed]
  18. The Urology Book. urologybook.com. Accessed September 12, 2016.
  19. Gómez Sancha F, Bachmann A, Choi BB, Tabatabaei S, Muir GH. Photoselective vaporization of the prostate (GreenLight PV): lessons learnt after 3500 procedures. Prostate Cancer and Prostatic Diseases. 2007;10(4):316-22. [pubmed]

 

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