Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an idiopathic but common benign condition which affects older men. The prevalence increases with age and it affects 70% of males > 60 years. It is characterised by a slowly growing prostate which compresses the urethra and causes chronic lower urinary tract obstruction, causing lower urinary tract symptoms (LUTS). It can be managed with medicines or surgical removal.

Etiology

• Multifactorial
• Sensitization of the prostate to androgens and oestrogens
• Higher oestrogen/testosterone ratio in elderly

Pathophysiology

• BPH originates from the transitional zone of the prostate
• BPH -> chronic bladder outlet obstruction -> LUTS
• There is no increased risk for prostate cancer

Clinical features

• Lower urinary tract symptoms like urinary urgency, frequency, incontinence, hesitancy, poor stream, etc.

Complications

• Recurrent urinary tract infection (due to the chronic urinary obstruction)
• Bladder stone
• Severe urinary tract obstruction

Diagnosis

• Diagnosis of BPH is clinical
  • Based on presence of LUTS in absence of other causes of LUTS
  • BPH does not require prostate biopsy
• International prostate symptom score (IPSS)
  • A questionnaire used to screen for, diagnose, and follow up symptoms of BPH
  • Points given from answers, the sum ranges from 0 – 35
  • The sum gives the severity of symptoms
• Urine analysis
  • If pyuria -> infection, which can cause similar symptoms
  • If haematuria -> can be tumor or ureter stone
• PSA
  • To look for co-existing prostate cancer
• Ultrasound
  • Can see stones, tumor, dilation of upper urinary tract
  • Can see prostate size
  • Can look for residual urine
  • Can see thickened bladder wall (detrusor hypertrophy)
• DRE
  • Symmetrically enlarged
  • Smooth (no nodules)
  • Firm
  • Nontender
  • Rubbery texture
• Uroflowmetry
  • Low peak flow, prolonged duration

Management

Behavioural modifications

• Restrict fluid intake before bedtime to prevent nycturia
• Reduce intake of diuretics like coffee, alcohol
• Urinating in sitting position

Medical therapy

• For voiding symptoms
  • Alpha-blockers
    • Tamsulosin, alfuzosin
    • Relax smooth muscle in bladder neck
    • Can cause hypotension, retrograde ejaculation
  • 5-alpha-reductase inhibitors
    • Finasteride, dutasteride
    • Decrease size of prostate
    • Takes 6 months for effect to set in
    • Can cause sexual dysfunction, gynecomastia
• For storage symptoms
  • Antimuscarinics
    • Oxybutynin, darifenacin
    • Decrease detrusor tone, increase bladder capacity
    • Can cause constipation, dry mouth, cognitive dysfunction (in elderly)
  • β-3 agonists
    • Mirabegron (Betmiga®)
    • Decrease detrusor tone, increase bladder capacity
    • More expensive
    • Does not have side effects of antimuscarinics

Surgical therapy

• Indications
  • Severe LUTS
  • BPH with complications
• Transurethral resection of the prostate (TUR-P)
  • Gold standard for BPH
  • Done under spinal/general anaesthesia
  • Only if the prostate is not very large (< 80 g)
  • A cautery resectoscope is led through the urethral opening and into the area of the prostate
    • The resectoscope has a camera like a cystoscope but is thicker, and has a metallic loop on the end
    • The metallic loop is a monopolar cautery, which is used to resect the prostate from the inside of the urethra
  • The prostate capsule is not removed
  • The remaining cavity will be epithelialized after a few months
  • TUR syndrome is a possible complication
• Simple prostatectomy
  • For large prostates (> 80g)
  • Only central and transitional zones are removed
    • Peripheral zone remains
  • Most commonly transvesically
    • Entry suprapubically
    • Operation is called transvesical adenectomy or Freyer prostatectomy
  • Can also be accessed through the perineum or the lower abdomen (retropubic)
• Newer methods
  • Laser ablation
  • Radioablation
  • Thermal ablation
• Radical prostatectomy is NOT used for BPH, only prostate cancer!