Benign diseases of the Prostate and Urinary Tract Obstruction Flashcards
What is the average size of the prostate gland in men aged 25-30 years?
20cc
describe the anatomy of the prostate?
what are the different mcneals prostatic zones?
what are different benign prostatic diseases?
Benign prostatic enlargement (BPE)
Benign prostatic hyperplasia (BPH)
Benign prostatic obstruction (BPO)
Bladder outflow obstruction (BOO)
Lower urinary tract symptoms (LUTS)
what is the hald diagram?
what is benign prostatic hyperplasia characterised by?
fibromuscular and glandular hyperplasia
Disordered regulation of dihydrotestosterone
what zone does benign prostatic hyperplasia predominantly affect?
transition zone
is benign prostatic hyperplasia part of the aging process in men?
yes
50% of men at 60 years
90% of men at 85 years
what do 50% of men with BPH have?
moderate to severe LUTS
Progressive condition resulting in Benign Prostatic Obstruction (BPO) or Bladder Outflow Obstruction (BOO)
what is the symptom scoring system for LUTS?
IPSS
what is the internation prostate symptom scoring out of?
35
what else assesses LUTS?
frequency volume chart
what should be done in physical examination of 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 should be done for benign prostate hyperplasia?
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
Urodynamic studies in selected cases
TRUS-guided prostate biopsy if PSA raised or abnormal DRE
what is a flow rate study?
what are two types of BPO?
Uncomplicated BPO
Complicated BPO
what is the algorithm for management of uncomplicated BPO?
what is the treatment for uncomplicated BPO?
Watchful waiting
Medical therapy
5 alpha reductase inhibitors (Finasteride or Dutasteride)
Alpha blockers
Combination
Surgical intervention
TURP (prostate size <100cc)
Open retropubic or transvesical prostatectomy (prostate size >100cc)
Endoscopic ablative procedures
what are alpha blockers?
Main treatment for LUTS due to BPO
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
what are types of alpha blockers?
- non-selective (i.e. alpha 1 and 2) : phenoxybenzamine
- selective short acting : prazosin, indoramin
- selective long acting : alfuzosin, doxazosin, terazosin
- highly selective (i.e. alpha-1a) : tamsulosin
are all alpha blockers effective?
All α−blockers appear to be equally effective but differences in side effect profiles and pharmacodynamic properties
what is TURP?
Transurethral resection of prostate
Remains gold standard for surgical management of BPE causing BOO (except for prostate size >100cc)
Can be done using glycine (monopolar TURP) or saline (bipolar TURP)
Very effective in relieving symptoms and improves urodynamic parameters (90% efficacy at 1 year)
what are complications of TURP?
bleeding, infection, retrograde ejaculation, stress urinary
incontinence, prostatic regrowth causing recurrent haematuria
or BOO
what are new alternative new endoscopic ablative procedures?
Transurethral laser vaporisation (KTP laser or Holmium laser)
- Transurethral holmium laser enucleation of prostate (HoLEP)
- Transurethral needle ablation of prostate using RFA (TUNA)
- Transurethral microwave therapy of prostate (TUMT)
why can TURP not be done for a prostate >100cc?
Too large for TURP – high risk of intra-operative or post-operative complications, including:
- bleeding
- fluid overload
- hypothermia
- TUR syndrome (triad of dilutional hyponatraemia, fluid overload and glycine toxicity) (only for monopolar TURP)
what are complications of 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
how is complicated BPO treated?
No role for medical therapy (except for acute urinary retention)
Most patients will require surgery
eg. cystolitholapaxy and TURP for patients with BPO and bladder stones
Alternative treatment options (eg. patients unfit for surgery) :
long term urethral or suprapubic catheterisation
clean intermittent self-catheterisation
may develop problems with difficult catheterisation, catheter trauma, blockages, frank haematuria or recurrent UTI
what is acute urinary retention?
‘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 is the main risk factor of 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)
what can occur spontaneously in those with BPO?
For those with BPO, can occur spontaneously (i.e. natural progression of BPO) or triggered by an unrelated event (eg. constipation, alcohol excess, post-operative causes, urological procedure)
what is the immediate treatment for acute urinary retention?
Immediate treatment is catheterisation (either urethral or suprapubic)
If no renal failure, start alpha blocker immediately and remove catheter in 2 days (60% will void successfully); if fail to void, recatheterise and organise TURP (after 6 weeks)
what are complications of acute urinary retention?
UTI, post-decompression haematuria, pathological diuresis, renal failure, electrolyte abnormalities
what is long term treatment for acute urinary retention?
If no renal failure, start alpha blocker immediately and remove catheter in 2 days (60% will void successfully); if fail to void, recatheterise and organise TURP (after 6 weeks)
what is chronic urinary retention?
‘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)
what is the main aetiological factor for chronic urinary retention?
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 does chronic urinary retention present?
Presents as LUTS or complications (e.g. UTI, bladder stones, overflow incontinence, post-renal or obstructive renal failure) or incidental finding
Overflow incontinence and renal failure occur at severe end of spectrum, when bladder capacity is reached and bladder pressure is in excess of 25cm water (i.e. decompensated chronic urinary retention or acute-on-chronic urinary retention or high pressure chronic urinary retention)
what is the treatment for chronic urinary retention?
Asymptomatic patients with low residuals do not necessarily need treatment
Patients with symptoms or complications need treatment (but no role for medical therapy!)
what is immediate treatment for chronic urinary retention?
Immediate treatment is catheterisation (either urethral or suprapubic initially, followed by CISC if appropriate)
what are complications of chronic urinary retention?
Complications : UTI, post-decompression haematuria, pathological diuresis, electrolyte abnormalities (hyponatraemia, hyperkalaemia, metabolic acidosis), persistent renal dysfunction due to acute tubular necrosis
what are pathological diuresis features?
urine output >200ml/hr + postural hypotension (systolic differential >20mm Hg between lying and standing) + weight loss + electrolyte abnormalities
what is long term management of chronic urinary retention?
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
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
The following are absolute indications for surgical intervention in patients with benign prostatic obstruction except:
a. refractory acute urinary retention
b. refractory chronic urinary retention
c. renal failure
d. recurrent UTI
e. failure of medical therapy to control symptoms
b. refractory chronic urinary retention
The following are common causes of acute urinary retention in men except:
a. spinal cord compression b. urinary tract infection c. constipation d. pain from laparotomy wound e. cystoscopy under local anaesthetic
e. cystoscopy under local anaesthetic
Short-term urethral catheters (e.g. latex-based ones) should not be left in-situ for longer than:
a. 1 week b. 4 weeks c. 8 weeks d. 12 weeks e. 16 weeks
b. 4 weeks
Long-term urethral catheters (e.g. silicone-based ones) should not be left in-situ for longer than:
a. 1 week b. 4 weeks c. 8 weeks d. 12 weeks e. 16 weeks
d. 12 weeks
what are types of upper tract urinary tract obstructions?
PUJ
ureter
VUJ
what are types of lower tract urinary tract obstructions?
- bladder neck (i.e. primary bladder neck obstruction, in men only)
- prostate (men only)
- urethra (e.g. urethral stricture in men and women; pelvic mass causing extrinsic compression of urethra in women)
- urethral meatus (i.e. meatal stenosis in men and women)
- foreskin (e.g. phimosis in men only)
what are intrinsic and extrinsic causes of upper urinary obstruction?
what are symptoms of upper urinary tract obstruction?
Pain
Frank haematuria
Symptoms of complications
what are signs of upper urinary tract obstruction?
Palpable mass
Microscopic haematuria
Signs of complications
what are complications of upper urinary tract obstruction?
Infection and sepsis
Renal failure (only if bilateral obstruction, single kidney or concurrent systemic upset e.g. sepsis, dehydration, nephrotoxicity)
Mr. Anderson is a 50 year old man who presents to
A&E with Left sided loin pain. The pain is colicky and
causes nausea and vomitting. He has no significant
past medical history and is not on any medications.
On examination, his temperature is 40°C, his pulse is
100 bpm, blood pressure is 90/60mm Hg, respiratory
rate is 20 bpm and O2 saturation is 89% on air. He is
extremely tender over the Left loin and flank areas.
what is the most important part of his management?
resuscitation
Mr. Anderson is a 50 year old man who presents to
A&E with Left sided loin pain. The pain is colicky and
causes nausea and vomitting. He has no significant
past medical history and is not on any medications.
On examination, his temperature is 40°C, his pulse is
100 bpm, blood pressure is 90/60mm Hg, respiratory
rate is 20 bpm and O2 saturation is 89% on air. He is
extremely tender over the Left loin and flank areas.
What investigations would you organise (i.e. after resuscitation)?
Abdominal/Renal tract ultrasound scan
what does a Abdominal/Renal tract ultrasound scan show?
If upper urinary tract is obstructed, USS will show:
- Hydronephrosis
- Hydroureter
However, cause of obstruction may not be visualised (obscured by bowel gas)
IVU (or IVP)
An intravenous urogram (IVU) is a test that looks at the whole of your urinary system. It’s sometimes called an intravenous pyelogram (IVP)
CT-KUB (non-contrast)
The advantage of non-contrast low-dose CT scan is its ability to measure the size and location of the calculus. This is important for an emergency physician who has to determine patient’s disposition and access to further treatment. Patients with small stones (<6 mm) and pain resolution can be safely discharged home.
CT-Urogram
It looks at the kidneys, ureters and bladder
Other types of imaging for upper urinary tract obstruction: MAG-3 renogram
when is this used?
Nuclear isotope (Technetium-99) scan to determine:
- Split renal function as a proportion of global renal function (e.g. 65% Right kidney; 35% Left; normal should be 50:50 split)
- Severity of obstruction based on drainage through renal outflow tract (e.g. mild, moderate or severe)
Not used in acute setting, nor for stones nor tumour
Used for chronic unilateral upper urinary tract obstruction, esp. chronic PUJ obstruction
when should CT-KUB be used?
- For investigation of urinary tract stones and obstruction in emergency setting
- Quick and lower radiation exposure (2-3 milliSieverts)
- No risk of contrast nephrotoxicity
- Can be used in renal failure
- Lower sensitivity for assessing obstructing masses (except for stones)
- Less useful if ureter and collecting system is undilated
when should CT urogram be used?
Higher radiation exposure (15-20 milliSieverts)
- Risk of contrast nephrotoxicity and contraindicated in renal failure
- Higher sensitivity for obstructing masses (e.g. ureteric UCC/TCC, pelvic mass)
summarise the management plan of an upper urinary tract obstruction?
Resuscitation
- 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)
Investigations (including imaging)
Emergency treatment of obstruction (for unremitting pain or complications)
- Percutaneous nephrostomy insertion OR
- Retrograde stent insertion
Definitive treatment of obstruction
- Treat underlying cause
- e.g. stone – ureteroscopy and laser lithotripsy +/- basketing or ESWL
- e.g. ureteric tumour – radical nephro-ureterectomy
- e.g. PUJ obstruction – laparoscopic pyeloplasty
what is the presentations of lower urinary tract obstruction?
Lower urinary tract symptoms
- voiding and storage, and urinary incontinence (overflow or urge)
Acute urinary retention
Chronic urinary retention
Recurrent urinary tract infection and sepsis
Frank haematuria
Formation of bladder stones
Renal failure (only for chronic high-pressure urinary retention)
PV bleeding (for women)
what should be done in the physical examination for lower urinary tract obstruction?
Lower urinary tract symptoms
- voiding and storage, and urinary incontinence (overflow or urge)
Acute urinary retention
Chronic urinary retention
Recurrent urinary tract infection and sepsis
Frank haematuria
Formation of bladder stones
Renal failure (only for chronic high-pressure urinary retention)
PV bleeding (for women)
what investigations should be done for lower urinary tract obstructions?
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; pelvic/transvaginal USS in women if pelvic mass suspected
Flexible cystoscopy if haematuria
Urodynamic studies in selected cases
TRUS-guided prostate biopsy if PSA raised or abnormal DRE
how is lower urinary tract obstruction managed in an emergency setting?
Resuscitation
- 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)
Investigations (including imaging: Bladder scan, USS renal tract, etc.)
Emergency treatment of obstruction (for unremitting pain or complications)
- Urethral catheterisation OR
- Suprapubic catheterisation
Definitive treatment of obstruction
- Treat underlying cause
- e.g. BPE – TURP
- e.g. Urethral stricture – Optical urethrotomy
- e.g. Meatal stenosis – Meatal dilatation
- e.g. Phimosis – Circumcision
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
First line treatment for 50 year old man with moderate lower urinary tract symptoms, slightly enlarged prostate (25cc) and poor urinary flow.
Alpha blocker
Treatment for 64 year old man with 2nd episode of acute urinary retention. He is already on an alpha blocker?
TURP
35 year old lady with temperature 40°C and Right loin and flank pain. CT-KUB has shown a 10mm stone at upper Right ureter causing severe hydronephrosis. Most appropriate treatment option
Nephrostomy insertion
This is an important lesson to learn. The patient is clearly unwell with obstructed infected kidney causing urosepsis. The mortality rate is very high. The most appropriate treatment option (apart from resuscitation, antibiotics, fluids, etc.) is immediate percutaneous nephrostomy insertion which will drain the kidney and relieve the infection. This is a life-saving intervention. For those who answered ESWL or Ureteroscopy and laser lithotripsy: These would be inappropriate because the patient is too unwell to go through these procedures. Also, these procedures will take time to undertake and time is a luxury we do not have when dealing with these critically ill patients. The only other alternative (which is deliberately not listed in the question) is cystoscopy and retrograde ureteric stent insertion which can also bypass the obstruction and drain the kidney and infection. In either cases (whether treated with nephrostomy or stent insertion), the stone is treated later on (usually weeks later) after the infection settles. This can be treated with ESWL or ureteroscopy and laser lithotripsy.
