Lecture 17 & 18: Bladder & Urethra (Exam 3) Flashcards
Define cystotomy
A surgical incision into the urinary bladder
Define cystostomy
The creation of an opening into the bladder
Define cystectomy
Removal of a portion of the urinary bladder
Define urethrotomy
An incision into the urethra
Define Cystolithiasis
Urinary bladder calculi
Define cystolithectomy
Removal of urinary bladder calculi
Define trigone
An area of the bladder is a smooth triangular portion of the mucous membrane
Define prepubic catherization
Temporary cystostomy usually performed to provide cutaneous urinary diversion in animals w/ urethral obstruction or trauma
Define Uroabdomen
Presence of urine in the abdominal cavity
Define urethrostomy
Creation of a permanent fistula into the urethra it is generally performed for irreparable or recurrent urethral stricture or to prevent repeated obstruction
What are the common indications for a cystotomy
- Remove calculi
- Repair trauma
- Resect or biopsy neoplasms
- Correct congenital abnorms
- Eval of urinary tract infection resistant to tx
Describe the surgical approach for a cystotomy
- Ventral midline approach of the caudal abdomen
- Longitudinal incision made on the ventral or dorsal surface of the bladder away from the urethra
- Place stay suture in the bladder
- Use simple continuous (two layer closure if it is thin)
Why is ventral exposure often preferred
The ease of access & should be performed if ID or catheterization of ureteral openings is necessary
What is the goal of cystotomy
To obtain a watertight seal that will not promote
What closure is sufficient in thick & normal bladder walls
Single layer appositional closure
When is cystotomy not believed to be associated w/ formation of calculus
If absorbable monofilament suture is used
T/F: You can diagnose the type of stone on the basis of crystals found in the urine
False you can not diagnose the type of stone on the basis of crystals found in the urine
When is surgical removal necessary
- Calcium oxalate
- Calcium phosphate
- Silicate stones
- Anatomic abnorms are present
- If medical can’t be done
- Need a culture
- Stones are too large
Describe the surgical tech of removing stones
- Perform cystotomy
- Incise a small piece of bladder for culture
- Remove the stones
- Check the urethra for other stones
- Examine the bladder for urachal diverticula
- Use retrohyropropulsion (if this does not remove obstruction use urethrotomy)
- Use a catheter to open the urethra (flush it)
When is retrohydropropulsion used
In male dogs to ensure there is no stones left in the urethral lumen by propelling urethral stones back into the bladder
How does retrohydropropulsion work
What should be done post stone removal
- Submit the stones for mineral analysis
- Perform abdominal radiographs
- Monitor for obstruction or leakage
- Sediment & pH monitored & UTI should be treated
What are some complications of cystotomy
- They are uncommon
- Failure to remove all the stones is the most common complication
- Urine leakage is possible
What is the main common complication of a urethrotomy
Hemorrhage
Are urethral strictures common
No
What is a traditional lithotripsy
- Uses shock waves to break up stones in the kidney, bladder, or ureter
- The tiny stones pass out of the body in the urine
What are the indications for a urethrotomy
- Males dogs to remove urethral calculi that can’t be retrohydropropulsed into the bladder
- Facilitate placement of catheters into the bladder
- Occasionally for a biopsy of obstructive lesions
when & why is a cystotomy preferred
- When: If calculi can be advanced back into the bladder by retrohydropulsion
- Why: to prevent possible post op urethral strictures
What are the common indications for a prescrotal urethrotomy
- Remove calculi from the distal penile urethra in dogs
- Place foley catheters into the urinary bladder (if the catheter is of sufficient length & the obstruction is distal to the incision)
What are the indications for a perineal urethrotomy
- Occ. to remove calculi lodged @ the ischial arch
- Place catheters into the bladder of large male dogs
What are the indications for a urethrostomy
- Recurrent obstructive calculi
- Calculi that cannot be removed other surgical ways
- Urethral stricture
- Urethral or penile neoplasia or severe trauma
- Preputial neoplasia req penile amputation
when is a scrotal urethrostomy preferred
If castration is an option & the lesion is distal to the scrotum
When is a perineal urethrostomy performed
Routinely in cats
What are the indications of a feline perineal urethrostomy
- To prevent recurrence of obstruction in male cats w/ feline idiopathic cystitis
- Treat obstruction that cannot be eliminated by catheterization
- Treat strictures secondary to urethral obstruction catheterization
Describe the tech of a prescrotal urethrotomy
- Ventral midline incision btw/ the scrotum & os penis
- Incision is made over the urethral catheter
- Calculi is removed & urethra flushed
Describe closure of a prescrotal urethrotomy
- May heal be secondary intention
- Primary closure is preferred if the mucosa is healthy
What are the advantages of a prescrotal urethrotomy
- Less invasive
- Good access to the distal penile urethra
- Effective for calculi remove when hydropropulsion fails
What are the disadvantages of a prescrotal urethrotomy
- Potential for post op bleeding
- Less ideal if multi or proximally located urethroliths exist
Describe the tech of a perineal urethrotomy
- Midline incision btw/ the anus & scrotum
- Separate the bulbospongiosus muscle to access the urethra
Describe the closure of a perineal urethrotomy
Urethra & subQ tissue is closed w/ absorbable sutures
What are the advantages of perineal urethrotomy
- Access to more proximal urethral regions
- Allows catheter placement when other approaches fail
What are the disadvantages of perineal urethrotomy
- Less commonly used
- Must close to prevent subQ urine leakage
- More technically demanding
Describe the tech of a canine perineal urethrostomy
Similar to perineal urethrotomy but the urethral mucosa is sutured to the skin
What is the advantage of a canine perineal urethrostomy
Last resort when other options fail
What are the disadvantages of a canine perineal urethrostomy
- High risk of urine scalding
- Profuse hemorrhage due to cavernous tissue
- Deep urethra leads to high suture tension & increases the risk of dehiscence
- Not commonly performed
Describe the tech of a canine prescrotal urethrostomy
- Similar to prescrotal urethrotomy but the mucosa is sutured to the skin
- Incision length is 6 to 8x the lumen diameter
- Interupted or continuous mucosa to skin sutures are used for closure
What are the advantages of a canine prescrotal urethrostomy
- Easier to perform in thin dogs
- Less hemorrhage than perineal site
What are the disadvantages of a canine prescrotal urethrostomy
- Higher stricture risk than the scrotal site
- Not ideal if lesion is proximal
Describe the technique of a canine scrotal urethrostomy
- Castration & scrotal ablation performed together
- Incision made over the urethra (more superficial here)
- Urethral mucosa is sutured to the skin
What are the advantages of a canine scrotal urethrostomy
- Urethra is wider & more superficial
- Less cavernous tissue so hemorrhage is reduced
- Lower stricture risk
- Better healing & lower complication rate
What are the disadvantages of the canine scrotal urethrostomy
- Req castration if intact
- May not reach more proximal lesions
Describe the tech of a feline perineal urethrostomy
- Penis is amputated @ the bulbourethral glands
- Urethra is dissected proximally beyond these glands
- Mucosa is sutured to the skin
What is a critical step of the feline perineal urethrostomy
- Ensure the urethral stoma is > or = to 5 mm (should admit a mosquito hemostat to boxlock)
- Failure predisposes to recurrent blockages
What are the advantages of a feline perineal urethrostomy
- High success rate in prevent recurrences
- Improved quality of life in blocked cats
What are the disadvantages of a feline perineal urethrostomy
- Risk of hemorrhage
- Risk of urine scalding
- Stricture if the urethral diameter is inadequate
- Surgical site infection & dehiscence is possible
What is the most critical step of a perineal urethrostomy
Pass a closed halsted mosquito hemostat up the urethra to ensure that the urethral width is adequate
What can happen if there is failure to perform the most critical step of a feline perineal urethrostomy
Can result in a urethral opening of insufficient diameter & predispose the px to urinary tract blockage & defeating the purpose of performing the surgery
