Surgery of urinary tract - Urethra + Ureters Flashcards
Are males or females more prone to urethral disease?
Males
What are the 3 regions of a male urethral tract?
- Prostatic
At neck of bladder
Surrounded by prostate - Pelvic
From prostate to ischial arch
Can be injured due to pelvic fractures - Penile
Ischial arch to orifice
Prone to obstruction, does not distend
What are the congenital abnormalities of the urethra?
- Hypospadias:
failure of fusion of the urogenital folds, incomplete formation of the urethra (abnormal urethral opening, more common in males) - Epispadias:
failure of fusion of the dorsal penile urethra - Urethral fistulas
urethrorectal : developmental abnormality of fetal cloaca
Urethrocutaneous
Can also be acquired
What are the acquired disorders of the urethra?
- Urethritis
- Urethral prolapse
- Urethral trauma
- Urethral stricture
- Urethral obstruction
- Neoplasia
What can cause urethritis?
UTI
urolithiasis
neoplasia
iatrogenic trauma
Treat underlying cause
What are the causes of urethral prolapse?
What breeds are at risk?
Abnormal development of urethra?
Increased intra-abdominal pressure due to laboured breathing?
Urethral infection?
Sexual excitement?
Brachycephalics - bulldog
What are the clinical signs of urethral prolapse?
Licking of penis
Bleeding
Protrusion of urethral mucosa through external urethral orifice of penis
What are the treatments of urethral prolapse?
Reduction of prolapsed segment if protrusion minimal and asymptomatic: catheterise urethra and
place purse string in tunic of penis at external urethral orifice for 5 days
Resection of prolapsed tissue: haematuria for few days postop
Castration
Recurrence
What is the most common urethral disease?
Urethral obstruction
What happens if an urethral obstruction isn’t treated?
- Requires urgent management, otherwise:
Uraemia and death
Prolonged bladder distention > loss of detrusor muscle may be
permanent
What are the different causes of urethral obstruction?
- Urolithiasis (male dogs: caudal ro os penis or ischial arch)
- Urethral plugs (mucus and crystals, male cats/FLUTD, distal 3rd of urethra)
- Neoplasia (bladder tumours invading urethra)
- Granuloma
- Bladder displacement/herniation
- Strictures
- Trauma
- Prostatic disease (dogs)
- Fracture of os penis
- Blood clots due to idiopathic renal haematuria
- Idiopathic
What are the clinical signs of urethral obstruction?
- Variable; depending on degree and duration of obstruction
- Dysuria
- Anuria
- Haematuria
- Dripping urine (owners may report ‘incontinence’)
- Abdominal distention
- Pain
- Signs of uraemia (>2days)
How would you diagnose urethral obstruction?
- History
- Abdominal palpation
- Inability to pass urinary catheter
- Abdominal Radiography
Plain radiographs (radio-opaque calculi)
Positive-contrast urethrography (displaced bladder, radiolucent calculi, soft tissue
lesions) - Abdominal ultrasound
How would you treat an urethral obstruction?
- Empty bladder – cystocentesis
- Fluid therapy
- Attempt urethral catheterization
Under ga
Pass catheter to obstruction and flush with saline
Doyen (intestinal) clamps on penis to occlude urethra
Empty bladder as saline will pass obstruction - Once obstruction resolved pass advance u+ catheter in the bladder and empty it
- Cystostomy to remove calculi
What is an urethrostomy?
Surgical procedure that creates a permanent opening from the urethra
What can cause urethral trauma?
Abdominal trauma
Pelvic fracture
Iatrogenic
What are the clinical signs of urethral trauma?
Haematuria, dysuria, anuria
Pain
Abdominal distention
Signs of peritonitis
Signs of uraemia
How would you diagnose urethral trauma?
- History
- Radiography (plain and retrograde urethrogram)
- Haematology and serum biochemistry
- Attempt urethral catheterization to establish urethral patency
- Stabilise patient with fluid therapy
How would you treat urethral trauma?
- For minor urethral trauma
Conservative management: place urethral catheter for 5-10 days - For extensive urethral trauma
Surgical repair
What animals tend to be affected by urethral tumours?
What type of tumours are more common?
- Old female dogs usually affected
- Less common than bladder tumours
- TCC and SCC more common
- Benign rare
- Metastasis in >50% of cases
How would you treat/manage urethral tumours?
- Surgery usually is not an option
- Surgical resection and urethral anastomosis via pubic osteotomy??
- Cystostomy tube
- Non-steroidal anti-inflammatories (NSAIDs)
- Stent
- Treatment is palliative, prognosis poor
What are the intraluminal, intramural and extramural causes of ureteral obstruction?
- Intraluminal
Calculus
Mass? Rare - Intramural
Fibrosis/stricture
Mass? Rare - Extramural
Compression or invasion by abdominal tumour;
rare except bladder tumours affecting the
trigone
Ligation of ureter during OHE
What will ureteral obstruction lead to if not treated within a week?
Hydronephrosis
What are the problems of ureteral surgery?
- Too small in diameter for safe surgery…
- Miscroscope/Loupes required; accurate surgery
- Risk of urine leakage
- Risk of healing by fibrosis which will cause stricture
