Treatment options for prostatic hypertrophy
- Conservative measures: fluid restriction, reduction caffeine intake
- Pharmacotherapy:
- alpha blockers (alfuzosin, doxzosin) - inhibit smooth muscle contraction
- 5-alpha-reductase inhibitor (finasteride) - block conversion of testosterone to DHT which limits size of prostate
- Surgical intervention
- Transurethral resection of the prostate (TURP)
- Transurethral incision of prostate for BOO
- Open retropubic prostatectomy - prostates > 80g in weight
- Transurethral microwave thermotherapy (TUMT)
- Transurethral needle ablation of the prostate (TUNA)
Indications for prostatic surgery
- Acute retention (where there is no other cause) / Chronic retention with evidence of renal failure
- Recurrent haematuria, urinary tract infection
- Voiding difficulties (hesitancy, poor flow, dribbling, incontinence) instability (frequency, urgency, incontinence)
Principles of Prostate surgery
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Prostatectomy = removal of hyperplastic mass of glandular tissue from surrounding prostatic gland which is compressed into a thin rim around it
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Approaches: (1) transvesically across bladder (2) retropubically through prostatic capsule (3) transurethrally
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in TURP, surgeon keeps proximal to verumontanum (colliculus seminalis) in order not to damage the urethral sphincter mechanism
Complications
- 90% success rate
- 1/6 require re-operation in 6 years
- Retrograde ejaculation (70%), impotence 20%, erectile dysfunction 5-10%
- Urethral strictures may be secondary to prolonged catheterisation / infection
- Incontinence normally up to 3 months
- Bleeding / infection common
- TUR syndrome - dilutional hyponatraemia secondary to excessive absorption of irrigation fluid intra-operatively
TUR syndrome
Pathogenesis: 20ml/minute fluid (isotonic glycine) can be absorbed with 1/3 absorbed into venous system directly (from exposed ends)
Risk factors (1) large prostate (2) long operation (3) high pressure irrigation (4) pre-operative hyponatraemia
Features:
- (hyponatraemia - swollen brain cells) - confusion, nausea, vomiting
- Fluid overload - pulmonary oedema
- Convulsions, coma
Symptoms occur generally when Na < 125 mmol/l
Up to 50% mortality rate
Treatment: support - O2, IV access, oral diuretics, fluid restrict