Key Facts

BPH is a histological diagnosis of non-malignant prostatic glandular and stromal cell proliferation. It causes bladder outflow obstruction (BOO) and lower urinary tract symptoms (LUTS), significantly impacting quality of life in ageing men.

Epidemiology

Histological BPH is present in approximately 50% of men by age 50 and 80% by age 80. Symptomatic BPH requiring treatment affects approximately 25% of men over 50. TURP is the most commonly performed urological operation, with approximately 25,000 procedures/year in England.

Aetiology

• Age: Principal risk factor — BPH does not occur before puberty
• Androgens: DHT (dihydrotestosterone) is the primary growth factor; conversion from testosterone by 5-alpha-reductase
• Growth factors: FGF, IGF, TGF-beta contribute to stromal hyperplasia
• Other factors: Metabolic syndrome, family history, ethnicity (higher in African-American men)

Pathophysiology

BPH involves hyperplasia of the prostatic transition zone, which surrounds the urethra. Two components cause symptoms:

1. Static component: Physical compression of the urethra by enlarged prostate tissue
2. Dynamic component: Increased smooth muscle tone mediated by alpha-1 adrenoreceptors in the prostate and bladder neck

Chronic BOO leads to detrusor muscle hypertrophy, trabeculation, diverticulae, and ultimately detrusor failure with overflow incontinence.

Voiding (Obstructive) Symptoms

• Hesitancy, poor stream, intermittency
• Terminal dribbling, straining to void
• Sensation of incomplete emptying

Storage (Irritative) Symptoms

• Frequency, urgency, nocturia
• Urge incontinence
• These may result from secondary detrusor overactivity

Acute Urinary Retention

• Painful inability to void
• Distended, palpable bladder
• May be precipitated by constipation, infection, surgery, medications (anticholinergics, sympathomimetics)

Complications of Untreated BPH

• Chronic retention with overflow incontinence
• Recurrent UTIs, bladder stones
• Hydronephrosis and renal impairment (obstructive uropathy)
• Haematuria

Red Flags

• Haematuria — exclude malignancy
• Raised creatinine with bilateral hydronephrosis — high-pressure chronic retention
• Weight loss, bone pain, hard irregular prostate on DRE — consider prostate cancer
• Rapid PSA rise — investigate for malignancy

Bedside

• IPSS (International Prostate Symptom Score): Quantifies symptom severity (0-35)
• Bladder diary: 3-day frequency/volume chart
• DRE: Assess prostate size, consistency (smooth = BPH; hard/irregular = cancer)
• Post-void residual (bladder scan): >300mL suggests significant retention

Bloods

• PSA: Mildly elevated in BPH (typically <10 ng/mL; proportional to prostate volume)
• U&Es: Renal function — high-pressure chronic retention
• FBC: If haematuria present

Imaging

• Renal USS: If chronic retention, raised creatinine, or recurrent UTI
• Transrectal USS (TRUS): Measure prostate volume (relevant for 5ARI therapy — >30cc)
• CT urogram: If haematuria requires investigation

Special Tests

• Uroflowmetry: Peak flow rate <10 mL/s suggests significant obstruction; <15 mL/s borderline
• Urodynamics: Pressure-flow studies — differentiate BOO from detrusor underactivity (recommended before surgery if diagnosis uncertain)
• Flexible cystoscopy: If haematuria or bladder pathology suspected

Non-pharmacological

• Watchful waiting: Mild symptoms (IPSS <8) — lifestyle advice, fluid management
• Lifestyle modifications: Reduce evening fluid intake, caffeine, alcohol; bladder training; timed voiding
• Review medications: Stop/switch drugs that worsen LUTS (anticholinergics, sympathomimetics, diuretics)

Pharmacological

• Alpha-blockers (first-line): Tamsulosin 400mcg OD — rapid onset (days); side effects include retrograde ejaculation, postural hypotension, floppy iris syndrome
• 5-alpha reductase inhibitors: Finasteride 5mg OD or dutasteride 500mcg OD — for prostate >30cc; takes 3-6 months; reduces volume by 25%, PSA by ~50%
• Combination therapy: Alpha-blocker + 5ARI for large prostates with moderate-severe symptoms (MTOPS and CombAT trials)
• Antimuscarinics: Tolterodine 2mg BD or solifenacin 5mg OD — for predominant OAB symptoms (ensure PVR <200mL)
• PDE5 inhibitor: Tadalafil 5mg OD — licensed for LUTS/BPH with concurrent ED

Surgical/Interventional

• TURP: Gold standard — unipolar or bipolar; improves flow rate by ~150%, IPSS by ~70%
• HoLEP (holmium laser enucleation): Size-independent, lower retreatment rate than TURP
• GreenLight laser (PVP): Vaporisation; good for anticoagulated patients
• Prostatic urethral lift (UroLift): Minimally invasive, preserves ejaculatory function (BPH-6 trial)
• Rezum (water vapour therapy): Thermal ablation; preserves ejaculatory function
• Open/robotic prostatectomy: For very large prostates (>80-100cc)

Referral Criteria

• LUTS not responding to medical therapy — urology
• Recurrent retention, UTIs, haematuria, bladder stones — surgical assessment
• Raised creatinine with bilateral hydronephrosis — urgent urology
• Haematuria requiring investigation — 2WW if malignancy suspected

• Natural history: Symptoms progress in approximately 30-40% of men over 5 years without treatment
• Medical therapy: Alpha-blockers improve symptoms in 60-70%; combination therapy reduces progression by 66% (CombAT trial)
• TURP outcomes: Symptom improvement in 85-90%; reoperation rate 5-10% at 10 years
• Acute retention: TWOC success rate 40-50% with tamsulosin; failed TWOC requires surgical intervention
• Chronic retention: Risk of irreversible detrusor failure if not treated; post-decompression diuresis can occur

IPSS Score Interpretation

Comparison of Surgical Options

Landmark Trials