Surgery of the urethra Flashcards
What is hypospadias? How do you treat it?
- Incomplete formation of the penile urethra
- Causes urination out of urethral orifice in abnormal location
- Nothing is done–congenital defect
What is a urethral prolapse?
Protrusion of urethra mucosa through orifice
What are the predisposing causes/etiologies for urethral prolapse?
- Young, male brachycephalic dogs
- Etiology is unknown
- Sexual excitement
- Dyspnea
- Infection
What are the clinical signs of urethral prolaspe?
- Bleeding from prepuce
- Licking
- Red-purple mass
What is the treatment for urethral prolapse if the animal is asymptomatic?
- Reduce with aid of large catheter
- Place purse string suture
- Leave for 5 days
What are the symptoms of urethral prolapse that would require more aggressive treatment?
- Excessive bleeding
- Ulcerative mucosa
- Necrosis
- Failure of conservative management
What are the options for surgical treatment of urethral prolapse? What is the adjunct treatment?
- Resection and anastomosis
- Urethropexy
- Adjunct treatment = castration + surgical correction of airway
Describe the procedure for resection and anastomosis of a urethral prolapse
- Place catheter
- Penile tourniquet (keeps penis extruded, controls bleeding)
- 180o incision (prevents mucosal retraction)
- Suture and complete resection
- Stay sutures in urethral mucosa
- Place 2 straight needles full thickness through urethra (prevents retraction)
- Transect and suture
Describe the procedure for a urethropexy as treatment for urethral prolapse
- Resect urethral mucosa
- Place groove director into urethra
- Place 3 full thickness sutures through penile wall and urethra
What are the clinical signs of urethral trauma?
- Hematuria
- Stranguria
- Subcutaneous or abdominal fluid accumulation
- Signs of azotemia
How do you diagnose urethral trauma?
Positive contrast urethrogram (very diagnostic)
Plain rads are NOT diagnostic
What is the treatment for small/incomplete urethral lacerations?
- Will heal with urinary diversion via urethral catheter or cystostomy tube
- Duration of catheterization depends on severity–minimum of 3 weeks
- Catheterization increases risk of stricture formation
What is the treatment for complete rupture of the urethra?
Anastomosis or repair with urinary diversion
What causes urethral obstruction in dogs and cats? Which are the most common?
- Mucus plugs
- Crystals/stones
- Neoplasia
- Strictures
- Most common cause in male dogs = calculi
- Most common cause in male cats = mucus plugs/crystals
T/F: Incidence of urethral obstruction has decreased due to changes in diets
TRUE
Where is urethral obstruction most common?
- Male dogs = ischial arch or just caudal to os penis
- Male cats = distal 1/3 of urethra
How do you diagnose urethral obstruction?
- Plain rads
- Radiopaque calculi
- Large distended bladder
- Ultrasound
- Contrast urethrography
What are the 7 goals of urethral obstruction treatment?
- Treat the patient first and deal with obstruction afterwards
- Renal fx preservation
- Uremia/electrolytes (must give fluids–BUN, CREA elevated)
- Treat UTI
- Prevent recurrence
- Catheter and fluids
- Temporarily relieve obstruction
What are the 3 procedures for temporarily relieving urethral obstructions?
- Retrograde hydropropulsion
- Feline urethral catheterization
- Surgical removal of calculi
Describe the process of retrograde hydropropulsion
- Palpate stone
- Compress urethra
- Pass catheter
- Pinch off orifice
- Inject saline
- Distend urethra
- Relieve compression
What are the 3 types of catheters used in feline urethral catheterization?
- Tomcat catheter
- Slippery Sam
- Red rubber catheter
What are the options for surgical removal of urethral calculi?
- Cystotomy after hydropropulsion
- Urethrotomy if hydropropulsion unsuccessful
- Often cystotomy combined with urethrotomy is performed
- Urethrostomy–to prevent recurrence if medical prevention is not possible
What are the indications for a urethrotomy in a dog?
Calculi that cannot be hydropropulsed
(Cystotomy is preferred)
Where (and why) is a urethrotomy performed in canines?
- Prescrotal
- Common obstruction
- Superficial
- Less cavernous tisue
What are the options for closure following a urethrotomy?
- 4/0 or 5/0 monofilament absorbable (very fine suture)
- Second intention
- Less risk of stricture
- Profuse hemorrhage
- Hospitalization (monitoring)
Why is a perineal urethrotomy less preferred in the canine?
- Difficult procedure (urethra deeper)
- Increased risk of infection
- Usually suture urethrotomy incision
Why is a perineal urethrostomy less preferred in canines?
- More tension
- More cavernous tissue
- More urine scald
- More UTIs
- Stenosis
What is a urethrostomy?
Surgical formation of a permanent opening of the urethra at a new site
Where is the preferred location for a urethrostomy in the canine? Why?
- Scrotal
- More superficial
- Relatively wide urethra
- Less hemorrhage
- Less urine scald (compared to perineal and pre-scrotal)
Where is the preferred location for a urethrostomy in the feline?
Perineal
What structures should be draped in the surgical field during a scrotal urethrostomy?
Abdomen, scrotum, prepuce
How long should the urethral incision for a scrotal urethrostomy be?
Midline incision in urethra should be 2.5-4cm long
(5-8x urethral diameter)
What is the most appropriate suturing method for a scrotal urethrostomy?
- Suture laterally to prevent impingement on urethra
- Make midline incision in urethra 2.5-4cm long
- Caudal extent where urethra turns dorsally into ischial arch
- Suture with 4/0 or 5/0 absorbable monofilament
- Accurately appose skin and mucosa
- Suture urethral mucosa to underlying fibrous tissue to the skin (tighter closure, minimizes hemorrhage)
- Take bites at edge of cavernous tissue (better strength, less hemorrhage)
What are the possible complications of a scrotal urethrostomy?
- Hemorrhage
- Dehiscence
- Urine scald
- Stricture
- UTI
What is a disadvantage of canine prescrotal urethrostomy?
Higher incidence of urine scald
When is a perineal urethrostomy in a cat indicated?
- Frequent obstructions
- Strictures
- Trauma
What are the goals of a perineal urethrostomy in cats?
- Adequate mobilization of urethra
- Preserve urethral branches of the internal pudendal nerve with minimal dorsal dissection
- Creation of a wide urethral orifice
What gland/area of the urethra do you dissect to when performing a perineal urethrostomy in a cat?
- Tranect ischiocavernosus and ischiourethralis muscles from their insertion on the ischium
- Excise retractor penis muscle dorsally
- Dissect to level of BBU gland
- Incise the urethra on dorsal midline
- Continue proximal to bulbospongiosus mucle/pelvic urethra
How can you check that the urethral orifice is wide enough during a perineal urethrostomy in a cat?
Ensure adequate width with mosquito hemostat to hinge
What are the complicatios of perineal urethrostomy in felines?
- Hemorrhage
- UTI
- Stricture
- Subcutaneous urine leakage
- Perineal hernia
- Urinary incontinence
- Urethrorectal fistula
How can you minimize stricture formation following perineal urethrostomy in a cat?
- Proper surgical technique
- May be revised with second procedure
- May require antepubic urethrostomy
What can cause subcutaneous urine leakage following a perineal urethrostomy in a cat?
How can you treat it?
- Improper suturing
- Urethral tear
- Treat with indwelling 8 French catheter for 5-7 days
What is an antepubic urethrostomy and when is it indicated?
- Creation of a urethrostomy on the ventral body wall cranial to the pubis
- Indications
- Recurrent pelvic urethral obstruction
- Failed perineal urethrostomy that cannot be revised
What are the possible complications of an antepubic urethrostomy?
- Urine scalding
- UTI
- Incontinence
What are the causes of urethral strictures?
- Usually caused by trauma
- Urethral sx
- Uroliths
- Iatrogenic from catheterization
- Healing after minor trauma
When do patients show clinical signs of urethral strictures?
>60% narrowing
How do you diagnose urethral strictures?
- Urethrogram
- Cystoscopy
How are urethral strictures treated?
- Treat if showing clinical signs
- Urethral dilators
- Balloon dilation
- Resection and anastomosis
- Proximal urethrostomy
