Urinary tract Flashcards
What is urolithiasis?
- Supersaturation of urine with stone forming chemicals
Are struvites formed in alkaline or acid urine?
Alkaline
Is calcium oxalate formed in alkaline or acid urine?
Acid urine
Rank the types of crystals in order of radio-opacity:
- Calcium oxalate
- Struvite
- Urate
Name the type of crystal that is shown below:
Struvite
Name the type of crystal that is shown below:
Calcium oxalate crystals
Name the type of crystal that is shown below and state three causes of it:
Urate:
- Congenital (Dalmation + Bulldog)
- Portosystemic shunt
- Liver failure
Name the type of crystal shown below and the cause:
Cystine - caused by an error in metabolism - they are radiolucent
Why are males more predisposed to urethral obstructions than females?
- Long thin highly muscular
What are the main diagnostic options for diagnosing a urethral obstruction?
- Urinanalysis
- Radiographs
- History
When is medical manangment of uroliths indicated?
- Struvite, urate and cysteine - can be an effective management strategy
- Not succesful if big stones or with calcium oxalate/silicate crystals
When is a nephrotomy indicated?
Nephrolithiasis - if it is large in size
For a ureteral obstruction:
- State when surgery should be done
- State how it can be diagnosed
- Briefly describe what the surgical options are to treat it
Ureteral obstruction:
- As soon as possible - surgery should be done to limit complications
- Diagnosis - ultrasound + CT (excretory urography) - may see one kidney much better than the others
- Surgical options = ureterotomy (cutting in), resection/anastomosis, ureteral reimplantation (if closer to the bladder), SUBS (Subcutaneous Ureteral Bypass System)
For bladder stones/ urethral stones:
- State three clinical signs that you would expect to see
- What presurgical treatments should be recommended?
- How can it be diagnosed
- Briefly explain how it should be treated surgically in the first instance (assuming it works)
Clinical signs:
- Bladder infection
- Dysuria/stranguria
- Haematuria
Presurgical treatments:
- Fluid therapy
Diagnosis:
- Radiographs
Treatment surgical:
- Flush stones back into bladder ⇒ stone removal ⇒ cystotomy
Briefly explain how to do pre-operative retro-hydropulsion:
Explain how to do a cystotomy with intra-operative retro-hydropulsion:
- Caudal midline celiotomy – drape in prepuce/vulva
- Pack off the urinary bladder with moist laparotomy pads
- Place stay sutures in the apex of the bladder and laterally
- Identify the median ligament of the bladder and remove this with Metzenbaum scissors
- Make a stab incision (11 blade) into the ventral surface of the bladder at the level of the median ligament and extend the incision with Metzenbaum scissors
- Remove the stones from the bladder atraumatically (keep stones for analysis!)
- Pass a urinary catheter from the outside (penis) to the level of the obstruction.
(for a female pass from inside (bladder) first to help with catheterisation - Flush the urethra retrograde.
- Flush the urethra normograde.
- Obtain a bladder mucosal sample for culture and sensitivity.
- Close the bladder in a simple interrupted appositional closure (4/0 PDS) - Submucosa strength layer + Local lavage
- Close the body wall, SC, skin (suture selection?)
