Benign diseases of the prostate and urinary tract obstruction Flashcards
How big is the average prostate?
20cc (like a walnut)
Who first described the prostatic zones?
McNeal’s prostatic zones
Describe Benign prostatic hyperplasia
• Characterised by fibromuscular and glandular hyperplasia
• Predominantly affects transition zone
• Part of aging process in men:
- 50% of men at 60 years
- 90% of men at 85 years
• 50% of men with BPH have moderate to severe LUTS
• Progressive condition resulting in Bladder Outflow Obstruction (BOO)
What % of men at 60yo have benign prostatic hyperplasia?
50%
What % of men at 85yo have benign prostatic hyperplasia?
90%
Which zone of the prostate is predominantly affected in benign prostatic hyperplasia?
Transition zone
How is severity of prostate disease LUTS symptoms assessed?
International prostate symptom score sheet
Total score (out of 35) suggests severity of symptoms:
o Mild: 0-7
o Moderate: 8-19
o Severe: ≥ 20
How are lower urinary tract symptoms (LUTS) assessed?
- Symptom scoring systems - IPSS
* Frequency volume charts
Describe the physical examination needed when investigating possible benign disease of the prostate
Abdomen
– ? palpable bladder
Penis
– ? external urethral meatal stricture
– ? phimosis
Digital rectal examination (DRE)
– assess prostate size
– ? suspicious nodules or firmness
Urinalysis
– ? blood
– ? signs of UTI
What investigations are used for benign diseases of the prostate?
MSSU
Flow rate study
Post-void bladder residual USS
Bloods:
– PSA
– Urea and creatinine (if chronic retention)
Renal tract USS if renal failure or bladder stone suspected
Flexible cystoscopy if haematuria or to visualise obstructions
Urodynamic studies in selected cases
TRUS-guided prostate biopsy if PSA raised or abnormal DRE
How is uncomplicated BPO treated?
Watchful waiting Medical therapy – Alpha blockers – 5 alpha reductase inhibitors (Finasteride or Dutasteride) – Combination – Surgical intervention – TURP (prostate size <100cc) – Open retropubic or transvesical prostatectomy (prostate size >100cc) – Endoscopic ablative procedures
What is the main treatment used for LUTS due to BPO?
Alpha blockers
- Smooth muscle of bladder neck (i.e. intrinsic urethral sphincter) and prostate innervated by sympathetic alpha-adrenergic nerves (mostly alpha-1a subtype)
- Alpha blockers cause smooth muscle relaxation and antagonise the ‘dynamic’ element to prostatic obstruction
Why are 5a reductase inhibitors used for BPO?
5a-reductase converts testosterone to dihydrotestosterone
- Reduces prostate size and reduces risks of progression of BPE (but only if >25cc prostate)
- Also reduces LUTS (but not as effective as alpha blockers)
- Combination therapy of 5ARIs + alpha blockers most effective in reducing risk of progression of BPE
- Can also reduce prostatic vascularity and hence reduces haematuria due to prostatic bleeding
- Potential role in prostate cancer prevention
What is TURP?
Trans-urethral resection of prostate
What is the gold standard surgical treatment of benign prostatic hyperplasia?
Trans-urethral resection of prostate/TURP
Describe efficacy of TURP 1 year after surgery
90%
What are some complications associated with TURP?
o Bleeding o Infection o Retrograde ejaculation o Stress urinary Incontinence o Prostatic regrowth causing recurrent haematuria or BOO
What are some alternative new endoscopic ablative techniques to TURP?
o Transurethral laser vaporisation
o Urolift
List some complications of benign prostatic obstruction (BPO)
- Progression of LUTS
- Acute urinary retention
- Chronic urinary retention
- Urinary incontinence (overflow)
- UTI
- Bladder stone
- Renal failure from obstructed ureteric outflow due to high bladder pressure
What are the alternative treatment options for complicated BPO?
– Long term urethral or suprapubic catheterisation
– Clean intermittent self-catheterisation
– May develop problems with difficult catheterisation, catheter trauma, blockages, frank haematuria or recurrent UTI
How is complicated BPO treated?
• Medical therapy
• Most patients will require surgery
– Eg. cystolitholapaxy and TURP for patients with BPO and bladder stones
• Some patients do not need any treatment (especially if residuals are relatively low, asymptomatic and no complications)
Describe acute urinary retention
- Defined as ‘an acute painful inability to void with a palpable and percussible bladder’
- Residuals vary from 500ml to >1 litre depending on time lag in seeking medical attention
What are some risk factors for acute urinary retention?
Main risk factor is BPO but can also occur independently of BPO (eg. UTI, urethral stricture, alcohol excess, post-operative causes, acute surgical or medical problems)
How is acute urinary retention treated?
Immediate catheterisation
If no renal failure, start alpha blocker immediately and remove catheter in 2 days (60% will void successfully)
If still fail to void, recatheterise and organise TURP (after 6 weeks)
List some complications of catheterisation in acute urinary retention
Complications: UTI, post-decompression haematuria, pathological diuresis, renal failure, electrolyte abnormalities
Describe chronic urinary retention
- Defined as ‘painless, palpable and percussible bladder after voiding’
- Patients often able to void but with residuals ranging from 400ml to >2 litres depending on stage of condition (i.e. wide spectrum)
- Main aetiological factor is detrusor underactivity which can be primary (i.e. primary bladder failure) or secondary (i.e. due to longstanding BOO, such as BPO or urethral stricture)
How is chronic urinary retention treated?
Only really required if symptomatic or with complications!
Immediate treatment is catheterisation (either urethral or suprapubic initially, followed by CISC if appropriate)
List some complications of catheterisation in chronic urinary retention
Complications: UTI, post-decompression haematuria, pathological diuresis, electrolyte abnormalities (hyponatraemia, hyperkalaemia, metabolic acidosis), persistent renal dysfunction due to acute tubular necrosis
Describe the features of pathological diuresis
Pathological diuresis features:
- urine output >200ml/hr
- postural hypotension (systolic differential >20mm Hg between lying and standing)
- weight loss
- electrolyte abnormalities
Define postural hypotension
systolic differential >20mm Hg between lying and standing
How is pathological diuresis following catheterisation in chronic urinary retention treated?
- Manage with iv fluids (total input = 90% of output) and monitor closely; liaise with renal team
- Subsequent treatment is with either long term urethral or suprapubic catheter, CISC or TURP
Patients with what type of urinary retention have better outcomes with TURP?
• TURP in chronic retention has a less successful outcome than for acute retention; however, patients with high pressure chronic retention has better outcome with TURP than patients with low pressure chronic retention
Describe the symptoms and signs of upper urinary tract obstruction
Symptoms
- Pain
- Frank haematuria
- Symptoms of complications
Signs
- Palpable mass
- Microscopic haematuria
- Signs of complications
What complications are associated with upper urinary tract obstructions?
• Complications
- Infection and sepsis
- Renal failure
Describe resuscitation used in upper urinary tract obstruction
- ABCs
- IV access, bloods, ABG, urine and blood cultures, fluid balance monitoring
- IV fluids, broad-spectrum antibiotics (if appropriate)
- Analgesia
- HDU care +/- renal replacement therapy (if appropriate)
List some emergency treatment for upper urinary tract obstruction for remitting pain or complications
– Percutaneous nephrostomy insertion
- Retrograde stent insertion
How are stones in the upper urinary tract treated?
ureteroscopy and laser lithotripsy +/- basketing or ESWL
How are ureteric tumours treated?
radical nephro-ureterectomy
How are PUJ obstructions treated?
laparoscopic pyeloplasty
How does lower urinary tract obstruction present?
- LUTS e.g. urinary incontinence
- Acute urinary retention
- Chronic urinary retention
- Recurrent urinary tract infection and sepsis
- Frank haematuria
- Formation of bladder stones
- Renal failure
Which size of urethral catheter is usually used in adults?
Urethral catheter - 14/16F size often used in adults
What is used for catheterisation if urethra is impassable?
16F suprapubic catheter (SPC) if urethra impassable
What is used to treat BPE if found to be causing lower urinary tract obstruction?
transurethral resection of prostate (TURP)
What is used to treat urethral strictures if found to be causing lower urinary tract obstruction?
Optical urethrotomy
What is used to treat mental stenosis if found to be causing lower urinary tract obstruction?
Meatal dilatation
What is used to treat Phimosis if found to be causing lower urinary tract obstruction?
Circumcision
List some potential causes of lower urinary tract obstruction
Phimosis
Meatal stenosis
Urethral strictures
Benign prostate enlargement
List some potential causes of upper urinary tract obstruction
Ureteric stone
Ureteric tumour
PUJ obstruction
Compare and contrast high pressure vs low pressure chronic retention
High pressure • Painless • Incontinent • Raised creatinine • Bilateral hydronephrosis
Low pressure • Painless • Dry • Normal creatinine • Normal kidneys
Describe decompression haematuria
– Shearing of small vessels due to differing compliance of tissue layers
– Usually self limiting
Describe post-obstructive diuresis
– Greater than 150-200ml/hr
– 0.5-50%
– Osmotic diuresis secondary to urea; ADH; altered tubular function
– Can lead to life threatening sodium and water depletion
– Normal saline at input = output-30ml/hr
What is the ‘gold standard’ investigation for renal colic?
a. Renal ultrasound scan
b. MRI of renal tract
c. IVU
d. CT-KUB
e. Plain KUB X-ray
d. CT-KUB
The following are common types of renal tract stones except:
a. Calcium phosphate
b. Calcium oxalate
c. Calcium bicarbonate
d. Uric acid (urate)
e. Magnesium ammonium phosphate (struvite)
c. Calcium bicarbonate