Surgery of the urinary tract – kidneys and bladder Flashcards
What are the main principles of urogenital surgery?
- Apply Halsted principles
- Gentle tissue handling
- Suture material: monofilament absorbable
Describe the anatomy of the kidneys
- Paired, bean-shaped retroperitoneal organs
- R more cranial than the L
- L more mobile than R; both more mobile in cats
What is the normal length of the kidneys in cats and dogs?
Renal size measured on VD abdominal radiographs
Cat: 2-2.5 x L2 length
Dog: 2.5-3.5 x L2 length
Name some developmental abnormalities of the kidney
- Renal agenesis (kidney and ureter not present)
- Renal dysplasia (disorganised parenchyma)
- Renal ectopia: should be functioning normally, just not in the right place
- Polycystic kidney disease (Persians, Bull terriers) *cysts can also be acquired
What are the indications for a renal biopsy?
- Renal mass (commonest indication)
- Haematuria of upper urinary tract origin
- Renal cortical disease / Protein-losing glomerulopathy
- Renal failure where underlying cause cannot be determined
• Be aware that if the kidney is already diseased, a biopsy may cause further damage
Renal biopsy should be performed after which other diagnostics?
- Haematology
- Serum biochemistry
- Urinalysis/urine bacteriology
- Diagnostic Imaging
- Coagulation profile: clotting factors, platelet numbers, etc
What are some contraindications for renal biopsy?
- Anaemia / Coagulopathy
- Oliguria / Anuria / Severe azotaemia
- Hypertension
- Urinary obstruction
- Hydronephrosis, cysts
- (Peri)renal abscess, pyelonephritis
- Solitary functioning kidney
What potential complications can occur with a renal biopsy?
- Haemorrhage (most common)
- Haematuria
- Hydronephrosis (obstruction by blood clots)
- Renal infarction
- Damage to renal vasculature
- AV fistula
- Infection
- Cyst or haematoma formation
- Renal fibrosis
What are the methods for renal biopsy?
- Fine Needle Aspirate (FNA): collects cells
- Tru-cut or Spring-loaded Biopsy instrument 14-18G: Collects tissue
- Surgical
What are the different approaches to the kidney?
- Percutaneous (blind) biopsy (not recommended)
- Ultrasound-guided biopsy
- Keyhole biopsy: flank approach
- Laparoscopic biopsy: requires specific training and equipment
- Ventral midline celiotomy: most common way
Where should the needle advance in the kidney when taking a biopsy?
Across the cortex only! not towards the hilus
During surgical approach which structures are moved to expose the kidney?
Retraction of the duodenum and descending colon towards the midline exposes the kidney
What is a nephrotomy used for?
- Used to obtain a Wedge biopsy
- Used in removal of nephroliths (nephrolithotomy)
Describe nephroliths and their clinical signs
- May be incidental finding
- Calculi occur more commonly in bladder than kidneys
- Clinical signs: lumbar/abdominal pain, haematuria, recurrent UTI, azotaemia
How are nephroliths treated?
- Medical management
- Calcium oxalate do not respond to medical management so have to be surgically removed
- Surgical management: consider referral
What is a ureternephrectomy?
Removal of the kidney and associated ureters
What are the indications for a ureternephrectomy?
- Trauma
- Hydronephrosis (ligated ureter?!)
- Renomegaly/renal masses
- Management of single ureteral ectopia?
- Harvest kidney for transplantation
What must a patient have to undergo a ureternephrectomy?
Functioning other kidney
What is the most common renal neoplasia in cats?
Lymphoma
What is the most common renal neoplasia in dogs?
Renal cell carcinoma
Describe the history and clinical signs of an animal with renal neoplasia
- Slow onset (weeks-months)
- Haematuria
- Weight loss
- Depression/lethargy
- Inappetence
- Pyrexia
- Lameness
- Abdominal distention
How is renal neoplasia investigated/diagnosed?
- Abdominal palpation
- Haematology and serum biochemistry
- Radiography
- Computed tomography
- Abdominal ultrasound
- Biopsy (FNA, Trucut, excisional)
- CHECK FOR METASTASIS
How is renal neoplasia treated?
- Lymphoma: chemotherapy, not surgical disease
- Unilateral renal neoplasia with no gross metastasis: Ureteronephrectomy
- Surgery can be challenging due to neovascularization
- Surgery is palliative until metastases become apparent
Describe two congenital abnormalities of the bladder
- Patent urachus: fetal communication between bladder and allantoic sac persists
- Vesicourachal diverticulum: external opening of urachus closes but blind-ending diverticulum remains open
What are the clinical signs of congenital abnormalities of the bladder?
Urine leakage, dermatitis, infection
What are the indications for cystotomy?
- Removal of calculi (stones)
- Repair of bladder trauma
- Biopsy or resection of bladder masses
- Biopsy of bladder wall
- Repair of ectopic ureters
How is the bladder closed?
- Monofilament suture material
- Single layer, simple interrupted or simple continuous
- 2-layer inverting continuous pattern
- Submucosa is the strength-holding layer
- Bladder heals quickly: 100% of normal tissue strength in 2-3 weeks
The majority of bladder calculi are made of?
Struvite or calcium oxalate
What are the signs of bladder calculi?
Haematuria
Pollakiuria (frequent, abnormal urination during the day)
Stanguria (painful, frequent urination of small volumes)
Dysuria (painful urination)
How are bladder calculi diagnosed?
- Haematology, serum biochemistry, urinalysis, urine bacteriology
- Plain radiography: you may not see urate, cystine, calcium phosphate
- Pneumocystography
- Double-contrast cystography
- Ultrasound
What are the causes of bladder rupture?
- Trauma
- Bladder neoplasia
- Urethral obstruction by calculi or neoplasia
- Iatrogenic: cystocentesis, catheterisation, manual expression
What are the signs of bladder rupture?
- Haematuria, anuria, dysuria
- Abdominal bruising
- Abdominal pain
- Abdominal distention
- Depression, vomiting or shock signs
How is bladder rupture diagnosed?
- History + clinical examination
- Absence of urine/haematuria on catheterisation
- Urethral obstruction at attempted catheterisation
- Azotaemia, dehydration, metabolic acidosis, hyperkalaemia
- Abdominocentesis: sample of abdominal free fluid for analysis
- Abdominal ultrasonography
- Positive contrast radiography
How is bladder rupture managed?
- Small tears heal spontaneously, place indwelling catheter for 1-3 days
- Fluid therapy + urine drainage:
• To normalise electrolyte levels, improve hydration + decrease azotaemia
• Indwelling catheter - Exploratory laparotomy: identify and repair defect
What is the use of a cystostomy tube?
Allows urinary diversion or to avoid bladder distention
Indications
• Bladder or urethral surgery
• Obstructive bladder neck or urethral neoplasia
• Neurogenic bladder atony
What is the most common bladder neoplasia in dogs and cats?
Transitional cell carcinoma
What are the clinical signs of a bladder neplasia?
- Dysuria, haematuria, pollakiuria, systemically ill
- UTI
How is a bladder neoplasia diagnosed?
- Haematology, serum biochemistry, urinalysis
- Ultrasound
- Double contrast cystography
- CT + thorax
- Catheter suction biopsy
- TCC biopsy: tumour seeding possible
How is a bladder neoplasia treated?
- Chemotherapy
- Non-steroidal anti-inflammatory drugs (NSAIDS)
- Cystostomy tube
- Urethral stenting
- Partial cystectomy: up to 75%, not if trigone affected
