Urology Flashcards
What are the three functions of the urinary tract?
- To collect urine produced by the kidneys
- To store urine collected safely
- To expel urine when socially acceptable
Where are the kidneys situated?
Retroperitoneal, between T11-L3
Where do the kidneys get their blood supply from?
Renal artery, which comes directly from the aorta at L1 level
Where is the prostate gland situated?
At the neck of the bladder
What are the four nerves controlling the bladder and sphincter?
- Pelvic nerve (involuntary)
- Hypogastric plexus (involuntary)
- Pudendal nerve (voluntary)
- Afferent pelvic nerve (sensory)
Which neurotransmitters are used in control of the bladder and sphincter?
ACh via the pelvic (parasympathetic) and pudendal (somatic) nerves.
Noradrenaline via the hypogastric plexus (sympathetic).
The afferent pelvic nerve carries sensory signals from which muscle?
Detrusor
Which parts of the brain control coordination of voiding?
Pontine micturition centre/periaqueductal grey
What controls the micturition reflex?
Sacral micturition centre
What controls the guarding reflex?
Onuf’s nucleus
What are the three phases of voiding?
Storage phase (98% of the time) Guarding reflex (if micturition inappropriate) Micturition reflex (if micturition appropriate)
Why does the pressure in the bladder remain low as the volume increases?
Due to receptive relaxation and detrusor muscle compliance
What do the nerves supplying the urinary tract do during the filling phase?
- Afferent pelvic nerve sends slow firing signals to the pons via the spinal cord
- Sympathetic stimulation via the hypogastric plexus maintains detrusor muscle relaxation
- Pudendal nerve stimulation maintains urethral contraction
Describe the micturition reflex
- Higher volumes in the bladder stimulate the afferent pelvic nerve to send fast signals to the sacral micturition centre in the sacral spinal cord
- The pelvic parasympathetic nerve is stimulated and the detrusor muscle contracts
- The pudendal nerve is inhibited and the external sphincter relaxes
Describe what happens during bladder emptying
- Coordinated detrusor contraction with external sphincter relaxation expels urine from the bladder
- A positive feedback loop is generated until all the urine is expelled
- Once complete, the detrusor relaxes and the external sphincter contracts.
Describe the guarding reflex
- Occurs when voiding is inappropriate, which is determined by afferent signals from the pelvic nerve being received by the PMC and PAG and being transmitted to higher cortical centres
- Sympathetic (hypogastric) nerve stimulation results in detrusor relaxation
- Pudendal nerve stimulation results in contraction of the external urethral sphincter
What are the lower urinary tract symptoms related to storage?
Frequency
Urgency
Nocturia
What are the lower urinary tract symptoms related to voiding?
Weak/intermittent stream Incomplete emptying Straining Hesitancy Terminal dribbling
What is benign prostatic hyperplasia?
Increased number of cells in the prostate, caused by epithelial and stroma proliferation or decreased apoptosis
What is benign prostatic enlargement?
Enlarged prostate found during physical examination/urological investigation
What can contribute to BPH?
Androgens, oestrogen, stromal epithelial interactions, growth factors and neurotransmitters
What is the role of androgens in BPH?
- Do not actually cause it, but required for BPH to occur.
- Androgen withdrawal can involute established BPH
- If androgen action/production is completely inhibited, BPH does not occur.
What is active benign prostatic obstruction?
Obstruction caused by contraction of the alpha-1 adrenoreceptor mediated smooth muscle
What is passive benign prostatic obstruction?
Obstruction caused by the volume effect of BPE
What scoring system can be used to assess patients with prostate-related symptoms?
IPSS - International Prostate Symptom Score, consists of 7 questions, graded 0-5
What are the first line investigations for a male patient with lower urinary tract symptoms?
- General examination
- Abdominal examination
- External genitalia examination (check for e.g. phimosis, meatal stenosis)
- Digital rectal examination (check for inner tone, prostate size/consistency, palpable nodules)
- Focused neurological examination
- Urinalysis (UTI/haematuria)
What are the second line investigations for a male patient with lower urinary tract symptoms?
- Flow rates and residual volume
- Frequency volume chart
- Renal biochemistry
- Imaging
- PSA?
- TRUSS (transrectal ultrasound)
- Urodynamics (in some cases)
What are the possible complications of BPH?
- Infections
- Stones
- Haematuria
- Acute retention
- Chronic retention
- Interactive obstructive uropathy
How is acute urinary retention treated?
Self-catheterisation or bladder outflow surgery
What symptom should alert the clinician to the risk of obstructive uropathy?
Nocturnal enuresis
What are the long term treatment options for obstructive uropathy?
Surgery (TURP) or indwelling catheter
Name two types of drugs that can be used to treat the symptoms of BPH
Alpha-adrenergic antagonists
5-alpha-reductase inhibitors
Name two alpha-adrenergic antagonists
Tamsulosin
Doxazosin
How do alpha-adrenergic antagonists help with the symptoms of BPH?
Promoting relaxation of the muscles around the prostate and bladder to allow increased flow of urine.
Name two 5-alpha-reductase inhibitors
Finasteride
Dutasteride
How do 5-alpha-reductase inhibitors help with the symptoms of BPH?
Inhibiting the conversion of testosterone to dihydrotestosterone (more active form), which results in a decrease in prostate size
Why would you normally start a patient on both an alpha-adrenergic antagonist and a 5-alpha-reductase inhibitor and then stop the alpha-adrenergic antagonist after 6-9 months?
The alpha-adrenergic antagonist gets to work faster, but only the 5 alpha-reductase-inhibitor will actually prevent symptomatic progression so best to start the AAA alongside the 5ARI until the 5ARI has had a chance to work.
What are the indications for surgery in patients with BPH?
- Bladder stones
- Recurrent gross haematuria
- Recurrent infections
- Therapy failure
What are the early complications of transurethral resection of prostate?
- Bleeding
- Sepsis
- Post TUR syndrome
- Retention (formation of clots inside catheter)
What are the late complications of transurethral resection of prostate?
- Retrograde ejaculation (all patients)
- Delayed bleeding
- Urethral stricture
- Bladder neck contracture
- Urinary incontinence
- Erectile dysfunction
What is a neuropathic bladder?
A bladder with dysfunctional voiding due to damage to the innervation
What things need to be assessed when investigating neuropathic bladder?
- Underlying cause (e.g. level and completeness of injury in spinal cord injury)
- Bladder sensation
- Incontinence (all the time?)
- Urgency
- UTI
- Haematuria
- Bowel function
- Sexual function
- Urinalysis +/- MSU
- USS renal tracts with post void residual measurement (check for signs of hydronephrosis and completeness of emptying)
- Flexible cystoscopy (can present with bladder stones)
- Video urodynamics
How is detrusor pressure calculated in video urodynamics?
A pressure transducer in the rectum measures the intra-abdominal pressure and a dual lumen pressure transducer in the bladder measures intra-vesical pressure. Detrusor pressure = intra-abdominal pressure - intra-vesical pressure
What should the detrusor pressure line look line on a urodynamic trace?
It should be completely flat until the patient is asked to pass urine and return to normal afterward.
How does a urodynamic study inform about bladder compliance?
Bladder compliance is the ability of the bladder to change volume without alteration in detrusor pressure.
Why is detrusor pressure >40 considered a problem?
Risks damage to the upper urinary tracts
What is reflex bladder?
A type of neuropathic bladder condition whereby the reflex cycle for micturition is intact.
What two issues can occur with reflex bladder?
- Detrusor overactivity (detrusor contracts when it shouldn’t)
- Detrusor-sphincter dyssenergia (sphincter doesn’t open early enough so detrusor keeps contracting until sphincter opens or until pressure overrides sphincter)
What is the main symptom of detrusor overactivity?
Urgency
What is the main symptom of detrusor-sphincter dyssynergia?
Only passing a small amount of urine
Why is detrusor-sphincter dyssynergia unsafe?
Risks upper UT damage
What is an areflexic bladder?
An acontractile bladder with no innervation to the detrusor, leading to retention.
Suprapontine lesions can be caused by cerebrovascular accident, dementia, cerebral palsy and brain tumours. What effect will these have on the bladder?
The inhibitory effect on the micturition centre will be lost, leading to storage symptoms and urgency etc.
Suprasacral lesions are most commonly caused by spinal cord injury and multiple sclerosis. What effect will these have on the bladder?
Micturition reflex is preserved but coordination and inhibition of the reflex is disrupted.
Sacral/infrasacral lesions can be caused by spina bifida, multiple sclerosis and trauma. What effect will these have on the bladder?
More likely to result in acontractile bladder. Dysfunction depends on level of the injury and whether complete or incomplete.
What are the 4 treatment options for neurogenic detrusor overactivity?
- Anticholinergic treatment
- Intravesical Botox + intermittent catheterisation
- Augmentation cystoplasty
- Ileal conduit
What are the 5 treatment options for detrusor sphincter dyssynergia?
- CISC (clean intermittent self catheterisation)
- Suprapubic catheter
- Sphincterotomy
- Augmentation cystoplasty +/- Mitrofanoff
- Ileal conduit
What are the management options for areflexic bladder?
- CISC (primary)
- Suprapubic catheter
- Sphincterotomy
- Ileal conduit
- Autologous fascial sling (if patient has stress incontinence)
What neuropathic bladder treatment is always the last resort and why?
Ileal conduit, due to the risk of infection and bleeding
What is autonomic dysreflexia?
A potentially life-threatening condition that can occur in patients with spinal cord injury at T6 or higher.
A noxious stimulus (e.g. tight clothing, pressure sore, faecal impaction, blocked catheter/full bladder/UTI) triggers a sympathetic response (tachycardia, sweating, flushing, increased BP, headache). The parasympathetic response is not enough to override the sympathetic response below the level of the injury, so results in vasodilation etc. above the injury but vasoconstriction etc. below the injury.
How is autonomic dysreflexia managed?
- Sit the patient upright to get gravity on your side
- 2 sprays of sublingual GTN to reduce blood pressure
- Treat noxious stimulus e.g. remove tight clothing, empty bladder, disimpact bowel
- Administer 5-10mg nifedipine if more time required to treat stimulus
- Contact anaesthetists - if ongoing assessment required, may require spinal anaesthetic.
What is urinary incontinence?
Involuntary loss of urine
What are the common causes of urinary incontinence?
DIAPERS: Delirium/dementia Infection Atrophic vaginitis/urethritis Pharmaceuticals/psychiatric causes Endocrine causes Restricted mobility Stool impaction
What is overflow incontinence?
Caused by retention, occurs as pressure overcomes the sphincter
What is the most common cause of continuous incontinence?
Vesico-vaginal fistula
What form is used to work out how severe incontinence is?
ICIQ
What should be assessed when taking history for urinary incontinence?
Onset, triggers, haematuria, obs and gynae history, past medical history, smoking status, bowel function, sexual function, bladder diary
What should be carried out during examination of a patient who presents with urinary incontinence?
Abdominal/pelvic examination, cough test, digital rectal examination, lower limb neurological examination, urinalysis +/- MUS, post void residual scan
What is urge urinary incontinence?
Involuntary loss of urine preceded by sudden urgency
What conservative measures can be used to improve the symptoms of urge incontinence?
Reducing caffeine intake, spicy foods, citrus drinks, weight loss, smoking cessation, bladder training
What may improve urge incontinence in patients with atrophic vaginitis?
Topical oestrogen cream
How do anticholinergic drugs such as oxybutynin and solifenacin reduce the symptoms of urge incontinence?
By inhibiting the muscarinic receptors in the detrusor muscle, thereby inhibiting detrusor contraction.
What is the second line pharmacological treatment for urge incontinence?
B3 agonists e.g. mirabegron, vibebegron - inhibit detrusor contraction
What is often seen on urodynamics in patients with urge incontinence?
‘Bumps’ of detrusor activity
What are the two options for surgical treatment of urge incontinence if pharmacological management is ineffective?
- Intravesical Botox
2. Sacral neuromodulation
What is stress urinary incontinence?
Involuntary loss of urine during activities that increase intra-abdominal pressure
What are the risk factors for stress urinary incontinence?
Age, obesity, parity (vaginal delivery, use of forceps), chronic constipation, chronic cough, vaginal prolapse
What is stress urinary incontinence usually caused by?
Urethral hypermobility, intrinsic sphincter deficiency or a combination of both
What conservative measures can be used to help with stress incontinence?
Lifestyle modifications e.g. smoking cessation, avoiding constipation, weight loss, reduction of caffeine intake
Pelvic floor muscle therapy
Containment e.g. pads, catheterisation
Duloxetine is an SNRI that relaxes the bladder and increases sphincter resistance. However, it is rarely used to treat stress incontinence now. Why?
Significant side effects reported by 24% of patients and increased rate of suicide.
What are the invasive treatment options for stress incontinence?
Urethral bulking agents
Buch colposuspension
Autologous fascial sling
Synthetic mesh tapes (scandal)
What is the most common cause of stress urinary incontinence in males?
Prostatectomy (can also be caused by TURP, pelvic radiotherapy and pelvic surgery)
How is male stress urinary incontinence treated?
Initially with pelvic floor muscle training
Gold standard management is an artificial urinary sphincter
What type of renal carcinoma is the most common?
Renal cell carcinoma
Other than renal cell carcinoma, what are two other types of kidney cancer?
Transitional cell carcinoma
Squamous cell carcinoma (very rare)
What can cause nephroblastoma in children?
Wilm’s tumour
Name two types of benign renal masses
- Oncocytoma
2. Angiomyolipoma
What type of cancer is renal cell carcinoma?
Adenocarcinoma
What are the risk factors for renal cell carcinoma?
Smoking, obesity, renal failure, hypertension, social deprivation
Where does renal cell carcinoma often metastasise to?
Lungs - ‘cannon ball’ metastases, also local invasion (blood vessels, adrenal gland).
How does renal cell carcinoma present?
Most found incidentally (asymptomatic) Can present with: Haematuria Loin pain Palpable mass Systemic symptoms e.g. fatigue, weight loss, bone pain etc.
Paraneoplastic syndromes are weird bodily effects caused by cancer. What are some of the effects?
Anaemia, polycythaemia, hypertension, hypercalcaemia, hypoglycaemia, Stauffer’s syndrome
What investigations should be carried out for suspected renal cell carcinoma?
FBC, U&E, LFT, coagulation
CT scan
Needle biopsy may be required to confirm diagnosis but if the tumour is large, should be operated on regardless
What is the gold standard treatment for small tumours confined to the kidney?
Partial nephrectomy
Why should renal cell carcinoma not be treated with radiotherapy?
Renal cell carcinoma is not radiosensitive
What is the operation for upper tract transitional cell carcinoma?
Nephroureterectomy - have to take out the entire ureter and maybe even part of the bladder too to avoid recurrence
What is the most common type of bladder cancer in the UK?
Transitional cell carcinoma
What is the most common type of bladder cancer in Egypt and why?
Squamous cell carcinoma due to endemic schistosomiasis