Lecture 18 + 19: Benign Diseases of the Urinary Tract Flashcards
How big is the prostate?
About the size of a walnut
2/3rd of the prostate is ____. 1/3rd is ____
Glandular
Fibromuscular
What surrounds the prostate gland?
Thin fibrous capsule
What is the clinical histological division of the prostate (McNeal’s zones)?
Central zone
Transitional zone
Peripheral zone
Which of McNeal’s zones is the biggest?
Peripheral
What does the central zone surround?
Ejaculatory ducts
Where is the transitional zone?
It is central and surrounds the urethra
Which zone’s glands typically undergo hyperplasia in BPH?
Transitional zone
In which zone is prostate cancer most common?
Peripheral zone
Which zone is felt most on DRE?
Peripheral
What is the arterial supply to the prostate?
Prostatic arteries (mainly derived from internal iliacs)
What is the venous drainage of the prostate?
Prostatic venous plexus (drained by internal iliac veins)
What is BPH characterised by?
Fibromuscular and glandular hyperplasia
What % of men have BPH at age 60 and age 85?
60 - 50% men
85 - 90%
BPH is a progressive condition leading to what?
Bladder outflow obstruction
How is the severity of BPH scored?
International prostate symptom score
Mild 0-7, moderate 8-19, severe is 20+
How does BPH tend to present?
LUTS (lower urinary tract symptoms)
How are LUTS categorised?
Voiding symptoms (obstructive) - weak/intermittent urinary flow, straining, hesitancy, terminal dribbling + incomplete emptying Storage symptoms (irritative) - urgency, frequency, urgency incontinence, nocturia Post-micturition - dribbling Complications - UTI, retention, obstructive uropathy
What investigations may be useful in BPH?
Urinalysis
PSA
International Prostate Symptom Score
Frequency volume charts
What things should you look for on examination of someone with suspected BPH?
Abdomen - ?palpable bladder
Penis - ?external urethral meatal stricture, ?phimosis
DRE - assess prostate size, ?suspicious nodules/firmness
Urinalysis - ?blood, ?UTI
What other investigations might you consider in someone with BPH?
MSSU Flow rate study Post-void bladder residual USS PSA, urea/cr if chronic retention Renal tract USS if renal failure/bladder stone suspected Flexible cystoscopy if haematuria Urodynamic studies in selected cases
What investigation should be done is PSA is raised or DRE is abnormal?
TRUS-guided prostate biopsy
What are management options for BPH?
Watchful waiting
Medications
Surgery
What medications can be used to treat BPH?
Alpha-1-antagonists
5 alpha-reductase inhibitors
Often used in combination
What surgery is used to treat BPH?
TURP - transurethral resection of prostate
Give e.g.s of alpha-1 antagonists
Tamsulosin, alfuzosin
How do alpha-1 antagonists work in treating BPH?
Decrease smooth muscle tone of bladder + prostate, thus antagonising the dynamic element to prostatic obstruction
What drugs are considered first line for BPH?
Alpha-1 antagonists
What AEs are associated with alpha-1 antagonists?
Dizziness, postural hypotension, dry mouth, depression
Give an e.g. of a 5-alpha reductase inhibitor
Finasteride
How do 5 alpha-reductase inhibitors work?
Block conversion of testosterone to dihydrotestosterone (which is known to induce BPH)
NB unlike alpha-1 antagonists they reduce prostate volume and decrease PSA but takes up to 6 months but doesn’t reduce LUTS as much as alpha-1 antagonists
What adverse effects are associated with 5 alpha-reductase inhibitors?
Erectile dysfunction, reduced libido, ejaculation problems, gynaecomastia
What surgical intervention is recommended if the prostate is <100cc?
TURP
What surgical intervention is recommended if the prostate is >100cc?
Open retropubic/transvesicular prostatectomy
Apart from TURP/open/transvesicular surgery what other surgical options are there for BPH?
Endoscopic ablative procedures
The smooth muscle fo the bladder neck (internal urethral sphincter) and prostate is innervated by what nerves?
Sympathetic alpha-adrenergic nerves
Is it best to use alpha-1 antagonists, 5 alpha-reductase inhibitors or a combination of both?
Combination of both
What are additional benefits of 5a-reductase inhibitors besides reducing prostate volume?
Reduces prostate vascularity –> reduced haematuria due to prostatic bleeding
Potential role in prostate cancer prevention
What is the gold standard treatment for BPH?
TURP
What are complications of TURP?
Bleeding Infection Retrograde ejaculation Stress urinary incontinence Prostatic regrowth leading to recurrent haematuria or BOO
What are alternative new endoscopic ablative procedures that can be used instead of TURP?
Transurethral laser vaporisation
What are complications of benign prostatic obstruction?
Progression of LUTS Acute/chronic urinary retention Urinary incontinence (overflow) UTI Bladder stone Renal failure from obstructed ureteric outflow due to high bladder pressure
What are treatment options for those with complicated BPO who are unfit for surgery?
Long term urethral/suprapubic catheterisation
CISC
Define acute urinary retention
Painful inability to avoid with a palpable and percussible bladder
What do the residuals in acute urinary retention vary from?
500ml to 1L
What is the main risk factor for acute urinary retention?
BPO
What are other aetiologies for acute urinary retention?
UTI Urethral stricture Alcohol excess Post-op causes Acute surgical/medical problems
How can acute urinary retention happen for those who have BPO?
Spontaneously i.e. natural progression of BPO
Triggered by unrelated event, e.g. constipation, alcohol excess, post-op causes, urological procedure
What is the immediate treatment of urinary retention?
Catheterisation (urethral/suprapubic)
What are complications of acute urinary retention?
UTI Post-decompressive haematuria Pathological diuresis Renal failure Electrolyte abnormalities
How do you manage acute urinary retention in someone with BPO as the underlying cause?
If no renal failure, start alpha blocker immediately, remove catheter in 2 days
If failure to void, recatheterize and organise TURP
Define chronic urinary retention
Painless, palpable + percussible bladder after voiding
What do the residuals in chronic urinary retention vary from?
400ml to >2L depending on stage of condition
What is the main aetiological factor in chronic urinary retention?
Detrusor inactivity - can be primary (i.e. primary bladder failure) or secondary (e.g. due to longstanding BOO, e.g. BPO or urethral stricture)
How does chronic urinary retention present?
LUTS or complications (e.g. UTI, stones, overflow incontinence, post-renal/obstructive renal failure)
What patients with chronic urinary retention require treatment?
Those with symptoms/complications
How is chronic urinary retention managed?
Immediately with catheterisation then CISC if appropriate
What are complications of chronic urinary retention?
UTI
Post-decompressive haematuria
Pathological diuresis
Electrolyte abnormalities (hyponatraemia, hyperkalaemia, metabolic acidosis)
Persistent renal dsyfunction due to acute tubular necrosis
What are features of pathological diuresis?
Urine output >200ml/hr + postural hypotension (systolic >20mmHg between lying and standing), + wt loss + electrolyte abnormalities
How is pathological diuresis managed?
IV fluids
Close monitoring
What is the future management of chronic urinary retention?
Long term urethral/suprapubic catheter
CISC
TURP
What are causes of urinary tract obstruction at the PUJ?
Instrinsic - Physiological PUJ obstruction Stone Ureteric tumour Blood clot Fungal ball
Extrinsic -
PUJ obstruction, e.g. crossing vessel
Tumour
What are causes of obstruction of the ureter?
Intrinsic - Stone Ureteric tumour (TCC) Scar tissue Blood clot Fungal ball
Extrinsic - LNs Iatrogenic Pregnancy Tumour
What are causes of obstruction at the VUJ?
Intrinsic -
Stone
Bladder/ureteric tumour
Extrinsic
Cervical tumour
Prostate cancer
What are symptoms/signs of upper urinary tract obstruction?
Pain
Haematuria
Palpable mass
What are complications of urinary tract obstruction?
Infection, sepsis
Renal failure
In men what does acute urinary retention most commonly occur secondary to?
BPH (enlarged prostate presses on urethra, which makes bladder wall thicker + less able to empty)
What other things apart from BPH can cause acute urinary retention?
Urethral obstructions - strictures, calculi, cystocele, constipation, masses
Rarer causes incl. neurological causes
What medications can cause acute urinary retention and how do they do this?
Affects nerve signals to the bladder - Anticholingerics TCAs Antihistamines Opioids Benzos
When does acute urinary retention often occur?
Post-op
Postpartum in women
How do patients in acute urinary retention typically present?
Inability to pass urine
Lower ab discomfort
Considerable pain/distress
What is a big difference in the presentation of acute vs chronic urinary retention?
Chronic usually painless
What signs are typical of acute urinary retention?
Palpable distended bladder
Lower ab tenderness
All women and men in urinary retention should have what examinations?
Both - DRE, neurological - assess for causes
Women - pelvic
What investigations should be done in acute urinary retention?
Urinalysis + culture
Serum UE, Cr to check for kidney injury
FBC, CRP to check for infection
What investigation should be done to confirm a diagnosis of acute urinary retention?
Bladder USS
Volume >300cc confirms diagnosis
What is the management of acute urinary retention?
Catheterisation
How should the patient in acute urinary retention be assessed after they are catheterised?
Measure volume of urine produced after 15m
<200 = not in acute urinary retention
>400cc = leave catheter in lace
If there is no obvious cause for acute urinary retention what should happen next?
Send to urologist to assess for of anatomical and urological causes
What are the two types of chronic urinary retention?
High pressure: impaired renal function + bilateral hydronephrosis, typically due to bladder outflow obstruction
Low pressure: no hydronephrosis, normal renal function
What commonly occurs after catheterisation for chronic urinary retention?
Decompression haematuria (due to rapid decrease in pressure in bladder --> shearing of small vessels) It does not req. treatment usually
What emergency treatments may be needed for upper urinary tract obstruction leading to retention?
Percutaneous nephrostomy insertion
Retrograde stent insertion
What does a nephrostomy involve?
Percutaneous puncture under LA + sedation
US/X-Ray guidance
It temporarily collects urine while the urinary tract is blocked
What kind of ureteric stents can be inserted?
Silicone
Polyurethane
Nickle titanium
How is lower tract obstruction leading to urinary retention managed?
Urethral catheterisation or suprapubic catheterisation
What is involved in ‘resus’ when a patient is in acute urinary retention?
ABC IV access, bloods, ABG, urine and blood cultures, fluid balance monitoring IV fluids, antibiotics Analgesia HDU care +/- renal replacement therapy
What things may cause lower urinary tract obstruction and how would you treat them?
BPH - TURP
Urethral stricture - optical urethrotomy
Meatal stenosis - meatal dilatation
Phimiosis - circumcision
How does high pressure chronic urinary retention present?
Painless
Incontinent
Raised Cr
Bilateral hydronephrosis
How does low pressure chronic urinary retention present?
Painless
Dry
Normal Cr and kidneys
Define post-obstructive diuresis
Prolonged urine production >= 200ml for at least 2h immediately following the relief of urinary retention or similar obstructive uropathy