Urinary surgery Flashcards
What/ who do we see in Urethral prolapse?
English bulldogs, hypersexual or UTI
Licking and haemorrhage
Castration alone unsuccesful
How do we surgically repair prolapse?
- Urinary catheter
- Incision hemi-circumference at ventral junction
of penile / urethral mucosa - 4/0 monofilament sutures
- Dorsal hemi-circumference
- Sedation 5-10 days, E-collar, isolation
post surgery complication?
poor apposition and mucosal haemorrhage or continued trauma
When do we see permanent stoma?
typically following urethral obstruction -> urolithiasis, stricture, trauma, neoplasia
usually end stage or salvage
Describe an acute obstruction
- Anuria
- Increased ureteric and renal pressure
- 0-10 mmHg to 50-150 mmHg within 10 mins
- Reduced GFR (by 80% at 24hr)
- Reduced renal blood flow
- Hyperkalaemic metabolic acidosis
–Most early changes functional and reversible
Describe a chronic obstruction?
- Pathological change in bladder, ureters, kidneys
- Hydroureter
- Muscular hypertrophy produces connective tissue
- Hydronephrosis
- Tubular dilation and cell atrophy
- Chronic renal failure
Describe what happens with chronic bladder distention?
- Detrusor thickening, collagen deposition
- Reduced contractility, compliance, denervation
Pre-op stabilisation?
- Bloods
- Corect azotaemia , hyperkalaemia 0.9% NaCl diuresis, avoid K if poss
- Urinalysis
- Imaging
What options for relief of urinary obstruction?
- Catheterisation
- Hydropulsion
- Intermittent cystocentesis
- Pre-pubic catheterisation -> Stamey Malecot (closed abdo) OR Tube cystotomy open abdo)
Describe Catheter/ Hydropulsion?
- Past small stones embedded in mucosal walls
- Hydropulsion to flush debris back into bladder
- sterile saline or 1:1 saline : KY
- Flushing with advancement in cats, with penile tip
occluded with fingers - Use in-dwelling catheter (low irritant) to guard
against repeated obstruction
Intermittent cysto?
- Particular care in obstruction
- Distention ischaemia
- Reduced bladder tissue blood flow by 25-30%
Pre-pubic catheter how to use both two forms
Stamey Malecot
* bladder too mobile
* early removal likely
Tube cystostomy
* sedation and local anaesthetic
* GA and mini-laparotomy
instrumentation ?
Haemorrhagic tissues
* Excessive trauma will increase risk of
complications
* Use fine instrumentation
* Use fine suture material
How to do urinary diversion in the dog?
Scrotal urethrostomy
- Urethra more superficial and wider at this location
- Less cavernous tissue
- Necessitates
wha about a pre-scrotal urethrostomy
- Allows removal of calculi at base of os penis
- Primary closure performed if blockage removed
- Can be converted to urethrostomy if calculi removal
impossible - Suitable if castration not permitted
Key features of pre-scrotal urethrotomy ?
- Healing by second intention possible
- No difference in urethral healing
- Inc risk of self-trauma and post-op complications, esp haemorrhage
Scrotal urethrosctomy?
- Urethra caheterised
- Urethrostomy
- Skin-mucosa
Stoma sie?
- Contracture common
- If original stoma too small, stenosis and stricture might occur
- Original stoma 3-4cm
Why is bleeding common with these surgeries?
- Sharp incision through cavernous tissue
- Venous haemorrhage can be dramatic
- Carefully close exposed surfaces
- Bleeding should be anticipated post op
- long term hospitalisation
What is the issue with urine leakage in cats?
- urine tissue contact leads to inflammation, oedema, cellulitis, wound infection
- Esp caustic to sub-epithelial tissue causing fibrosis and delayed healing
S/C urine leakage signs?
- Initial bruising, pain and swelling
- Skin becomes discoloured, ‘sweaty’ and firm
- Skin white, necrotic and sloughs
- Azotaemia develops
- +/- urine output
Describe a Uroperitoneum
- Fluid, electrolytes and proteins
- Post-renal azotaemia, hyperphosphataemia
- Na and Cl into peritoneum, K reabsorbed
- Chemical peritonitis
- Fluid urea approximates serum urea
- Fluid creatinine greater then serum creatinine (2:1)
Indications for temporary diversion?
- Trauma -> inc scar formation, urine irritating
- Neoplasia > palliative
- Atony -> chronic distention leading to loss of CM contractility
why is diversion helpful in atony cases?
- allows recovery of tight junction
- Prevents urethral irritation
- Aids patient management
- Normal micturition ca resume whilst tube is in place
Describe a tube cystotomy?
Foley catheter
Possible diversion for
weeks-months
Can measure urine
output (1-2ml/kg/hr)
Well tolerated
Easy home care
Complications of tube cysto?
URI
- Nasocomial bacteria lielly -> must resolve once tube is removed + ABs
Permament stoma usually following …
urethral obstruciton (urolithiasis, stricture, neoplasia, trauma)
-> usually end stage or salvage
Describe Perineal urethrostomy ?
Straightforward procedure
Well-tolerated, with good clinical results
Only addresses immediate urinary dysfunction
Client education vital, cat may continue to posture
