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
- Alpha-blockers
- 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
- 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!