17. urinary surgery 3

urethral obstruction — presenting signs

• stranguria, dysuria, pollakiuria, hematuria

  • may be confused with constipation

• uremia

  • signs and symptoms associated with renal failure (build-up of urinary waste products in blood)

• metabolic acidosis

• hyperkalemia-associated arrhythmias

hyperkalemia-associated arrhythmias — ECG changes

• bradycardia

• absent or small P waves

• prolonged QRS width & PR intervals

• spiked T waves

• ventricular arrhythmias

complications of prolonged urinary tract obstruction

• loss of detrusor function (atony)

• bladder necrosis

UTO diagnostics

• palpate the bladder!

• evaluate hemodynamic status

  • blood pressure, ECG, chemistry panel, blood gas

UTO initial treatment

correct metabolic derangements

• diuresis (LRS better than NaCl)

  • correct uremia & acidosis

• hyperkalemia

  • insulin, bicarbonate, albuterol — transiently drives K⁺ intracellularly

• cardiac protectants

  • calcium gluconate — restores normal membrane excitability

    • (note: does nothing to correct K⁺)

• decompress bladder

  • urethral catheter

  • cystocentesis — if catheter cannot be passed

  • tube cystostomy

• do not sedate until patient is stable

urethral imaging

• plain radiographs — include entire urethra

• positive-contrast urethrocystography

  • filling defects

  • contrast extravasation

• ultrasound — only if extrapelvic

  • (bladder or external urethra)

• CT scan or MRI

• urethroscopy (size of urethra = limiting factor)

urethral obstruction surgeries

• urethrotomy (“otomy” = incise)

• urethrostomy ('“ostomy” = stoma — leave opening in urethra to bypass problem)

• urinary diversion

  • speedy healing / less fibrosis

  • cystostomy or transurethral catheter

  • (intact bowel or isolated segment

    • high complication rate)

urethrotomy locations — male dogs

• prescrotal — preferred

• perineal

• prepubic

urethrotomy procedure — male dogs

• place urinary catheter to identify urethra

• incise on midline of urethra

  • move retractor penis muscle laterally

• remove calculi

• catheterize antegrade & retrograde

• can leave wound open to heal by 2nd intention or close

urethrostomy indications

• recurrent obstructions

• permanent urethral damage

• malignant neoplasia

urethrostomy locations

• male cats

  • perineal or prepubic

• male dogs

  • prescrotal, scrotal, perineal, or prepubic

• female cats & dogs

  • prepubic

perineal urethrostomy — technique

• primarily male cats

  • not preferred site in dogs — poor cosmesis; urine scald

• decreases (does not eliminate) potential for urethral obstruction

• distal penis is removed to bulbourethral glands (wide enough to minimize obstruction)

• tension-free closure

  • 4-0 to 5-0 monofilament nonabsorbable (or absorbable) suture

  • typically interrupted sutures

  • 1.0-1.5 cm stoma

scrotal urethrostomy — technique

• male dogs

• place catheter retrograde

• circumferential incision around scrotum

  • castrate if needed

  • leave adequate skin

• fix retractor penis muscle in lateral position

• fix SQ tissue to tunic

• incise on midline

• suture skin to urethra

  • non-asorbable preferable

prepubic urethrostomy

• male or female dogs or cats

• salvage procedure

  • recurrent pelvic obstruction, failed perineal urethrostomy, neoplasia

• preserve maximal length of functional urethra

• midline position in females & male cats

• paramedian in male dogs

  • partial prostatectomy

• avoid acute bend in urethra

• spatulate urethra & suture to skin

urethral trauma — complete disruption

• anastomosis

• approach

  • abdominal

  • pelvic

  • osteotomy

  • perineal

• debride ends

• close with single layer

• minimize tension

• place urethral catheter?

urethral neoplasia treatment options

• surgery

• tube cystostomy

• urethral stenting

• radiation

urethral prolapse — signalment

• young, male brachycephalic dogs

• may be related to increased abdominal pressure

urethral prolapse treatment options

• manual reduction

  • urethral catheter + purse-string suture

• resection & anastamosis

  • urethral mucosal retracts

  • 4-0 to 5-0 absorbable

• urethropexy

urethral sphincter incontinence — medical management

• overall high success rates — first line treatment

• estrogens

  • cause increased responsiveness to alpha receptors to sympathetic stimulation

• alpha (adrenergic) agonists: phenylpropanolamine (PPA)

  • side effects: hypertension, diarrhea, tachycardia, increased intraocular pressure, or hyperexcitability

urethral sphincter incontinence — surgical management

• relocate a pelvic bladder

  • colposuspension

  • urethropexy

  • cystopexy

• increase urethral resistance

  • periurethral surgical slings

  • artificial sphincters — salvage option

  • intraurethral bulking agents

    • collagen & other synthetic materials

recessed vulva — associated problems & surgical tx

associated problems

• perivulvar dermatitis

• urinary tract infection

• urine pooling / incontinence

surgical treatment

• episioplasty