Introduction

Benign prostatic hyperplasia occurs most commonly in men over 60. The term benign prostatic hypertrophy is often used interchangeably with benign prostatic hyperplasia, but is less correct. Hyperplasia refers to an increase in the number of “components” (e.g. glands), whilst hypertrophy refers to an increase in the size of individual components.

  • Affects up to 40% of men over 40, and 90% of men over 80
    • It is very rare in Asian men
  • Considered a variation of normal physiology
  • Microscopically there is hyperplasia of both the connective (stromal) tissue, and of the glandular (epithelial) tissue
    • Grows most rapidly between the ages of 30-50 – when it can double in size about every 5 years
  • Thought to be the result of a failure of apoptosis
    • Some of the drugs used in treatment are through to increase the rate of apoptosis
  • Nearly All men will develop BPH if they live long enough. About ½ of all men will have macroscopic enlargement, and one half of these will have symptoms.
  • The prostate naturally grows throughout life – it grows in response to dihyrotestosterone – a breakdown product of testosterone. As such, BPH does not occur in castrated men
  • May manifest symptomatically with lower urinary tract symptoms (LUTS), including increased urinary frequency, sensation of not being able to empty the bladder, poor urinary flow.
    • Be aware that other potentially serious conditions can also cause LUTS – e.g. prostate cancer
  • BPH does not make prostate cancer more likely
  • Bladder outflow obstruction, as a result of BPH, is associated with:
    • Urinary retention
    • Recurrent UTI
    • Impaired renal function
    • Haematuria

Presentation

  • Lower urinary tract symptoms – LUTS
    • Frequency of urination (notably nocturia) is the most common early symptom
      • Try to distinguish true polyuria, from increased frequency. True polyuria is large amounts of urine frequency. The increased urinary frequency of an enlarged prostate usually just involve small amounts of urine passed
    • Hesitation in initiating urination.
    • Reduced force of the urinary stream
    • Post-void dribbling
    • Retention of urine resulting in overflow incontinence
    • Incontinence may occur
  • A benign prostate will always feel smooth on digital rectal examination (DRE)
  • Size is relevant but is not always associated to the severity of the symptoms
  • Symptom score – such as the IPSS – International Prostate Symptoms Score
    • Scores classed as mild. moderate or severe

Examination

  • PR (DRE – digital rectal examination)
    • BPH usually causes a smooth, symmetrical prostate enlargement. The dental sulcus can usually be palpated
    • Be on the lookout for any signs of prostate cancer (hard, craggy, irregular and asymmetrical prostate)
    • Assessing size – each finger breads of width of a prostate is equivalent to about 20g of prostatic mass
  • Abdominal examination – check for a palpable bladder which indicates urinary retention (usually chronic if painless, acute retention is very painful)

Investigations

  • PSA
    • Should be performed as a screen or prostate cancer in men with LUTS
    • May be normal or raised
    • May be useful to perform a “free” and “total” PSA in cases of raised PSA to determine the cause. Non cancerous causes of raised PSA will have a free PSA of >15% total
    • More information about PSA is available in the prostate cancer article
  • Urine MC+S and dipstick – for any signs of UTI which may suggest a prostatitis
  • Bloods
    • Check urea and electrolytes for any evidence of renal failure
    • LFTs – particularly alkaline phosphate – can be raised if there is metastatic prostate cancer to the bone. Beware there are other causes of raised ALP  – such as Paget Disease of the Bone
  • Rectal ultrasound
    • Can be useful to assess the size and shape of the prostate prior to surgery. Not a routine investigation
  • Bladder scan – consider this in any male with LUTS to assess for retention
  • Renal ultrasound – can help determine if there is retention, and the cause of any urinary obstruction
  • Cystoscopy – may be performed if a bladder lesion or urethral stricture is suspected. Often performed after prolonged use of indwelling catheter and failure of catheter removal
  • Urine flow analysis
    • Qmax – is the maximum urinary flow rate and the most useful test to confirm BPH. However, it is also reduced in bladder contractility disorders
    • Qmax >15mls/sec is normal
    • Qmax <7mls/sec is considered low
    • At least two separate readings are required to confirm the results
  • Pressure study
    • Invasive procedure to measure the pressure during voiding
    • Voiding pressure >60cm water (plus a Qmax <15mls/sec) is diagnostic

Differentials

  • Prostate Cancer
  • Chronic prostatitis
  • Bladder tumour
  • Detrusor instability
  • UTI
  • Urinary stricture
  • Interstitial cystitis

Management

  • Often no treatment is necessary. Patients with mild symptoms should not be given treatment if they feel they can cope, due to the adverse effects many of the treatments. Sometimes symptoms after treatment may be worse than symptoms before treatment!
    • Bear in mind that symptoms tend to worsen over time
    • Regularly reassess symptoms and offer treatments as necessary
  • Lifestyle factors
    • Reduce natural diuretics (caffeine, alcohol)
    • Avoid large volume of fluid intake in the evening
    • Avoid constipation
    • Bladder training and pelvic floor exercises can improve symptoms
  • Patients with moderate symptoms (IPSS >7) can be managed medically:
    • α-blockers – alfuzosin, doxazosin, tamsulosin – these reduce smooth muscle contractions of the bladder and urethra – they generally reduce the muscle tension in these regions. This allows for easier passing of urine.
      • Can lower blood pressure – particularly troublesome in those with a history of orthostatic hypotension
      • Risk of floppy iris syndrome in cataract surgery – ensure any ophthalmologist is aware of this medication if prescribed
      • Can also cause erectile dysfunction and retrograde ejaculation
    • 5α- reductase – finasteride – these reduce the conversion of testosterone to dihyrotestosterone and thus help to shrink the size of the prostate. These take 4-6 months to have an effect
      • Have been shown to improve long-term outcome, including reducing risk of retention and reducing the need for surgery
      • Can cause sexual dysfunction – less likely than with alpha-blockers
      • Typically need to be continued for several years
      • Are available in combination preparations with alpha-blockers
  • Patients with more severe symptoms and/or failure to respond to medical treatment should be considered for surgery. These symptoms may include urinary retention, renal damage, and upper urinary tract dilation. No surgical option should be considered completely definitive.
    • TURP – transurethral resection of the prostate – This is the standard surgical treatment. Part of the prostate is cut out via the urethra. It can be done under general or local anaesthetic. About 14% of patients will have sexual sexual dysfunction (erectile dysfunction and / or retrograde ejaculation), and 20% of patients will need further surgery within 10 years. Urethral stricture can also occur. Bleeding may be hard to control and all patients will require an indwelling catheter until the bleeding stops
    • TUIP – transurethral incision of the prostate – also TUNA – transurethral needle ablation – two similar procedure – both of which are minimally invasive. These the best option for those with symptomatic small prostate glands (<30g). It removes less of the prostate than TURP and as a result, greatly reduces the chance of sexual dysfunction. However, they are also less effective than TURP and symptom more likely to recur
    • TUVP – transurethral vaporisation of the prostate – an open surgery technique, reserved for those with a very large prostate (80g or more). May cause large blood loss requiring transfusion. Has good long-term outcomes, but a much more involved proceeder than TURP.
    • HoLEP – holmium laser enucleation of the prostate – a new technique with fewer complications than TURP and appears to be equally as effective. Is preferred to TURP in some centres (where available)
  • In cases of acute retention, or retention with overflow, the immediate priority is to relieve discomfort and pain, and often catheterisation is a good idea. The urethral catheterization is not possible, then subra-pubic catheterization may be carried out. This involves sticking a tube through the abdominal wall directly into the bladder. It is often done in cases where the patient needs to be catheterized for a prolonged period.

References

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