Urology Flashcards
Renal Stones Hydronephrosis Benign Prostatic Hyperplasia LUTS & Urinary Incontinence Testicular & Scrotal Issues
Renal stones: risk factors?
dehydration
hypercalciuria, hyperparathyroidism, hypercalcaemia
cystinuria
high dietary oxalate
renal tubular acidosis
medullary sponge kidney, polycystic kidney disease
beryllium or cadmium exposure
Risk factors for urate stones
gout
ileostomy: loss of bicarbonate and fluid results in acidic urine, causing the precipitation of uric acid
drugs that promote calcium stones
loop diuretics, steroids, acetazolamide, theophylline
Which drugs can prevent calcium stones?
thiazides can prevent calcium stones (increase distal tubular calcium resorption)
What are the different types of renal stones?
Calcium oxalate Calcium phosphate Uric Acid Struvate Cystine
Commonest type of renal calculi?
Calcium oxalate
Risk factors for oxalate stones?
Hypercalciuria is a major risk factor (various causes)
Hyperoxaluria may also increase risk
Hypocitraturia increases risk because citrate forms complexes with calcium making it more soluble
Are calcium oxalate stones lucent or opaque?
Stones are radio-opaque (though less than calcium phosphate stones)
Hyperuricosuria may cause calcium oxalate stones?
Hyperuricosuria may cause uric acid stones to which calcium oxalate binds
Which is the least common stone?
Cystine 1%
How do cystine stones arise?
Inherited recessive disorder of transmembrane cystine transport leading to decreased absorption of cystine from intestine and renal tubule
Cystine stones present with multiple stones
true
Cystine stones radiolucency?
Relatively radiodense because they contain sulphur
Semi-opaque, ‘ground-glass’ appearance
Uric acid stones arise due to
Uric acid is a product of purine metabolism
May precipitate when urinary pH low
May be caused by diseases with extensive tissue breakdown e.g. malignancy
Uric acid prevalence? Most common in
5-10%
More common in children with inborn errors of metabolism
Uric acid radiology
Radiolucent
Calcium phosphate stones arise due to
May occur in renal tubular acidosis, high urinary pH increases supersaturation of urine with calcium and phosphate
Renal tubular acidosis types 1 and 3 increase risk of stone formation (types 2 and 4 do not)
Calcium phosphate prevalence?
10%
Calcium phosphate radiology?
Radio-opaque stones (composition similar to bone)
Struvite stones arise due to
Stones formed from magnesium, ammonium and phosphate
Occur as a result of urease producing bacteria (and are thus associated with chronic infections)
Under the alkaline conditions produced, the crystals can precipitate
Struvite stone prevalence
2-20%
Struvite radiology
Slightly radio-opaque
How does urine ph vary?
Urine pH will show individual variation (from pH 5-7).
Post prandially the pH falls as purine metabolism will produce uric acid.
Then the urine becomes more alkaline (alkaline tide).
When the stone is not available for analysis the pH of urine may help to determine which stone was present.
Describe stone types vs urine acidity and ph
Calcium phosphate Normal- alkaline Calcium oxalate Variable Uric acid Acidic Struvate Alkaline Cystine Normal
Which stones are radio-opaque?
Calcium oxalate
Calcium phosphate
Mixed calcium oxalate/phosphate stones
Triple phosphate stones
Which stones are radioo lucent
Urate stones
Xanthine stones
stag-horn calculi involve the renal pelvis and extend into at least 2 calyces.
true
Staghorn calculi arise due to?
develop in alkaline urine and are composed of struvite (ammonium magnesium phosphate, triple phosphate). Ureaplasma urealyticum and Proteus infections predispose to their formation
BAUS endorse the use of alpha-adrenergic blockers to aid ureteric stone passage routinely.
FALSE
They do however acknowledge a recently published meta-analysis advocates the use of α-blockers for patients amenable to conservative management, with greatest benefit amongst those with larger stones
How to manage analgesia in renal colic?
BAUS recommend an NSAID as the analgesia of choice for renal colic
whilst diclofenac has been traditionally used the increased risk of cardiovascular events with certain NSAIDs (e.g. diclofenac, ibuprofen) should be considered when prescribing
the CKS guidelines suggest for patients who require admission: ‘Administer a parenteral analgesic (such as intramuscular diclofenac) for rapid relief of severe pain’
Intial ix for renal colic?
urine dipstick and culture
serum creatinine and electrolytes: check renal function
FBC / CRP: look for associated infection
calcium/urate: look for underlying causes
also: clotting if percutaneous intervention planned and blood cultures if pyrexial or other signs of sepsis
BAUS now recommend that what should be performed on all patients with renal colic
non-contrast CT KUB
How soon should non-contrast CT KUB be performed in renal colic
within 14 hours of admission
if a patient has a fever, a solitary kidney or when the diagnosis is uncertain an immediate CT KUB should be performed.
In the case of an uncertain diagnosis, this is to exclude other diagnoses such as ruptured abdominal aortic aneurysm
Describe sensitivity & specificity of CT KUB for renal stones
CT KUB has a sensitivity of 97% for ureteric stones and a specificity of 95%
US is diagnostic renal stones
false
ultrasound still has a role but given the wider availability of CT now and greater accurary it is no longer recommend first-line. The sensitivity of ultrasound for stones is around 45% and specificity is around 90%
Stones ? size will usually pass spontaneously.
Typically pass within ? weeks?
< 5 mm
Most renal stones measuring less than 5mm in maximum diameter will typically pass within 4 weeks of symptom onset
More intensive and urgent treatment is indicated in the presence of what pmh
(in renal stones)
ureteric obstruction
renal developmental abnormality such as horseshoe kidney
previous renal transplant.
Mx ureteric obstruction due to stones?
Ureteric obstruction due to stones together with infection is a surgical emergency and the system must be decompressed. Options include nephrostomy tube placement, insertion of ureteric catheters and ureteric stent placement.
In the non-emergency setting, the preferred options for treatment of stone disease include
extra corporeal shock wave lithotripsy
percutaneous nephrolithotomy
ureteroscopy
open surgery remains an option for selected cases. However, minimally invasive options are the most popular first-line treatment.
Describe Shockwave lithotripsy
A shock wave is generated external to the patient, internally cavitation bubbles and mechanical stress lead to stone fragmentation.
The procedure is uncomfortable for patients and analgesia is required during the procedure and afterwards.
The passage of shock waves can result in the development of solid organ injury. Fragmentation of larger stones may result in the development of ureteric obstruction.
Describe Ureteroscopy
A ureteroscope is passed retrograde through the ureter and into the renal pelvis. It is indicated in individuals (e.g. pregnant females) where lithotripsy is contraindicated and in complex stone disease. In most cases a stent is left in situ for 4 weeks after the procedure.
Describe Percutaneous nephrolithotomy
In this procedure, access is gained to the renal collecting system. Once access is achieved, intra corporeal lithotripsy or stone fragmentation is performed and stone fragments removed.
Describe the indication for Lithotripsy
Stone burden of less than 2cm in aggregate
Describe the indication for Ureteroscopy
Stone burden of less than 2cm in pregnant females
Describe the indication for Percutaneous nephrolithotomy
Complex renal calculi and staghorn calculi
Describe the indication for Manage expectantly
Ureteric calculi less than 5mm
Describe prevention strategy for Calcium stones
Mx hypercalciuria, which is found in up to 5-10% of the general population.
high fluid intake
low animal protein
low salt diet (a low calcium diet has not been shown to be superior to a normocalcaemic diet)
thiazides diuretics (increase distal tubular calcium resorption)
Describe prevention strategy for oxalate stones
cholestyramine or pyridoxine
reduce urinary oxalate secretion
Describe prevention strategy for uric acid stones?
allopurinol
urinary alkalinization e.g. oral bicarbonate
Benign prostatic hyperplasia (BPH) is a common condition seen in older men.
true
Risk factors bph
age: around 50% of 50-year-old men will have evidence of BPH and 30% will have symptoms. Around 80% of 80-year-old men have evidence of BPH
ethnicity: black > white > Asian
BPH typically presents with lower urinary tract symptoms (LUTS)
true
Management options BPH
watchful waiting
medication: alpha-1 antagonists, 5 alpha-reductase inhibitors. The use of combination therapy was supported by the Medical Therapy Of Prostatic Symptoms (MTOPS) trial
surgery: transurethral resection of prostate (TURP)
Give examples of Alpha-1 antagonists . How do these work? What are the adverse effects
tamsulosin, alfuzosin
decrease smooth muscle tone (prostate and bladder)
considered first-line
adverse effects: dizziness, postural hypotension, dry mouth, depression
Give examples of 5 alpha-reductase inhibitors . How do these work? What are the adverse effects
finasteride
block the conversion of testosterone to dihydrotestosterone (DHT), which is known to induce BPH
unlike alpha-1 antagonists causes a reduction in prostate volume and hence may slow disease progression.
adverse effects: erectile dysfunction, reduced libido, ejaculation problems, gynaecomastia
alpha 1 antagonists improve symptoms in around ?% of men
70%
5 alpha-reductase inhibitors increase PSA
false
may also decrease PSA concentrations by up to 50%
When would you expect to see symptom improvement in bph after using 5 alpha-reductase inhibitors
after 6 months
luts are most commonly secondary to benign prostatic hyperplasia but other causes should be considered including prostate cancer.
true
examination and ix in luts?
urinalysis: exclude infection, check for haematuria
digital rectal examination: size and consistency of prostate
a PSA test may be indicated, but the patient should be properly counselled first
In LUTS It is useful to get the patient to complete the following to guide management:
urinary frequency-volume chart: distinguish between urinary frequency, polyuria, nocturia, and nocturnal polyuria.
International Prostate Symptom Score (IPSS): assess the impact on the patient’s life. This classifies the symptoms as mild, moderate or severe
voiding symptoms ?
(obstructive): weak or intermittent urinary flow, straining, hesitancy, terminal dribbling and incomplete emptying
storage symptoms
(irritative) urgency, frequency, urgency incontinence and nocturia
post-micturition sx? Complications of this?
dribbling
Sensation of incomplete emptying
complications: urinary tract infection, retention, obstructive uropathy
mx Predominately voiding symptoms
conservative measures include: pelvic floor muscle training, bladder training, prudent fluid intake and containment products
if ‘moderate’ or ‘severe’ symptoms offer an alpha-blocker
if the prostate is enlarged AND the patient is ‘considered at high risk of progression’ then a 5-alpha reductase inhibitor should be offered
if the patient has an enlarged prostate AND ‘moderate’ or ‘severe’ symptoms offer both an alpha-blocker and 5-alpha reductase inhibitor
if there are mixed symptoms of voiding and storage not responding to an alpha blocker then a antimuscarinic (anticholinergic) drug may be added
mx Predominately overactive bladder
conservative measures include moderating fluid intake
bladder retraining should be offered
antimuscarinic drugs should be offered if symptoms persist. NICE recommend:
oxybutynin (immediate release)
tolterodine (immediate release),
or darifenacin (once daily preparation)
mirabegron may be considered if first-line drugs fail
mx nocturia
advise about moderating fluid intake at night
furosemide 40mg in late afternoon may be considered
desmopressin may also be helpful
Urinary incontinence (UI) is a common problem, affecting around 4-5% of the population. It is more common in
elderly females.
risk factors urinary incontinence
advancing age previous pregnancy and childbirth high body mass index hysterectomy family history
Describe 4 types urinary incontinence
overactive bladder (OAB)/urge incontinence: due to detrusor overactivity
stress incontinence: leaking small amounts when coughing or laughing
mixed incontinence: both urge and stress
overflow incontinence: due to bladder outlet obstruction, e.g. due to prostate enlargement
Intial investigation of urinary incontinence?
bladder diaries should be completed for a minimum of 3 days
vaginal examination to exclude pelvic organ prolapse and ability to initiate voluntary contraction of pelvic floor muscles (‘Kegel’ exercises)
urine dipstick and culture
urodynamic studies
Management of urinary incontinence URGE
bladder retraining (lasts for a minimum of 6 weeks, the idea is to gradually increase the intervals between voiding)
antimuscarinics are first-line. NICE recommend:
oxybutynin (immediate release) but avoid in ‘frail older women’, tolterodine (immediate release) or darifenacin (once daily preparation)
mirabegron (a beta-3 agonist) may be useful if there is concern about anticholinergic side-effects in frail elderly patients
Management of stress incontinence?
pelvic floor muscle training: NICE recommend at least 8 contractions performed 3 times per day for a minimum of 3 months
surgical procedures: e.g. retropubic mid-urethral tape procedures
duloxetine may be offered to women if they decline surgical procedures
What is duloxetine?
a combined noradrenaline and serotonin reuptake inhibitor
mechanism of action: increased synaptic concentration of noradrenaline and serotonin within the pudendal nerve → increased stimulation of urethral striated muscles within the sphincter → enhanced
contraction
Causes of unilateral hydronephrosis
PACT Pelvic-ureteric obstruction (congenital or acquired) Aberrant renal vessels Calculi Tumours of renal pelvis
Causes of bilateral hydronephrosis?
SUPER Stenosis of the urethra Urethral valve Prostatic enlargement Extensive bladder tumour Retro-peritoneal fibrosis
Ix hydronephrosis?
ultrasound - first-line: identifies presence of hydronephrosis and can assess the kidneys
IVU- assess the position of the obstruction
Antegrade or retrograde pyelography- allows treatment
if suspect renal colic: CT scan (majority of stones are detected this way)
mx hydronephrosis
Remove the obstruction and drainage of urine
Acute upper urinary tract obstruction: nephrostomy tube
Chronic upper urinary tract obstruction: ureteric stent or a pyeloplasty
How does hydrocele present?
mass that transilluminates, usually possible to ‘get above’ it on examination.
Non painful, soft fluctuant swelling
Usually contain clear fluid
Ix hydrocele
In younger men it should be investigated with USS to exclude tumour.
Why would hydrocele arise in children
patent processus vaginalis.
Mx hydrocele
Treatment in adults is with a Lords or Jabouley procedure.
Treatment in children is with trans inguinal ligation of PPV.
How does inguinal hernia present
If inguinoscrotal swelling; cannot ‘get above it’ on examination
Cough impulse may be present
May be reducible
How do testicular tumours present? What investigations would you do?
Often discrete testicular nodule (may have associated hydrocele)
Symptoms of metastatic disease may be present
USS scrotum and serum AFP and β HCG required
How do epidymal cysts present?
Single or multiple cysts
May contain clear or opalescent fluid (spermatoceles)
Usually occur over 40 years of age
Painless
Lie above and behind testis
It is usually possible to ‘get above the lump’ on examination
Hydrocele May be presenting feature of testicular cancer in young men
true
Varicocele typically arises in right or left side
Typically occur on left (because testicular vein drains into renal vein)
Varicocele may be presenting feature of what
renal cell carcinoma
In varicocele Affected testis may be ? and bilateral varicoceles may affect ?
Affected testis may be smaller and bilateral varicoceles may affect fertility
Testicular malignancy is always treated with orchidectomy via an inguinal approach. why
This allows high ligation of the testicular vessels and avoids exposure of another lymphatic field to the tumour
Intermittent torsion is a recognised problem. The treatment is prompt surgical exploration and testicular fixation. This can be achieved using
using sutures or by placement of the testis in a Dartos pouch.
Varicoceles are usually managed conservatively. If there are concerns about testicular function of infertility then surgery or radiological management can be considered.
true
Epididymal cysts can be excised using a scrotal approach
yes
Hydrocele mx? Which approach is used in adults vs children
managed differently in children where the underlying pathology is a patent processus vaginalis and therefore an inguinal approach is used in children so that the processus can be ligated.
In adults a scrotal approach is preferred and the hydrocele sac excised or plicated.
A congenital undescended testis is one that has failed to reach the bottom of the scrotum by
3 months of age.
At birth up to 5% of boys will have an undescended testis
tru
post natal descent occurs in most and by 3 months the incidence of cryptorchidism falls to 1-2%. In the vast majority of cases the cause of the maldescent is unknown
cryptorchidism may be assoc congenital defects including:
Patent processus vaginalis Abnormal epididymis Cerebral palsy Mental retardation Wilms tumour Abdominal wall defects (e.g. gastroschisis, prune belly syndrome)
Males with undescended testis are 40 times as likely to develop testicular cancer (seminoma) as males without undescended testis
true
The location of the undescended testis affects the relative risk of testicular cancer (50% intra-abdominal testes)
Reasons for correction of cryptorchidism
Reduce risk of infertility
Allows the testes to be examined for testicular cancer
Avoid testicular torsion
Cosmetic appearance
Treatment undescended testes
Orchidopexy at 6- 18 months of age. The operation usually consists of inguinal exploration, mobilisation of the testis and implantation into a dartos pouch.
Intra-abdominal testis should be evaluated laparoscopically and mobilised. Whether this is a single stage or two stage procedure depends upon the exact location.
After the age of 2 years in untreated individuals the Sertoli cells will degrade and those presenting late in teenage years may be better served by orchidectomy than to try and salvage a non functioning testis with an increased risk of malignancy.
