Surgery of the Bladder Flashcards
Which part of the urinary tract is more commonly affected by surgical conditions?
Lower urinary tract
What is the difference between cat and dog urinary bladder anatomy?
In dogs, it lies just cranial to or within the pelvic cavity when empty and extends ventro-cranially into the abdomen as it distends. In cats, the bladder is always intraabdominal, even when empty.
How us the dog urethra divided?
prostatic, pelvic and penile portion.
What is the longest section of dog urethra?
penile
What is the penile urethra segment surrounded by?
Corpus spongiosum
Where does the urethra pass through the prostate?
prostatic section, where the ampullae of the ductus deferens enter on either side of the dorsally located colliculus seminalis.
Where does urethra diameter increase in dogs?
Proximal
How long does it take for urethral mucosa to completely regenerate?
7 days
What portion of urethra is present in cat but not dog?
Preprostatic
What does pre prostatic portion form?
Urethral sphincter
What is the blood supply to the bladder via?
Cranial and caudal vesical arteries
What does the cranial vesicle artery branch from?
Umbilical artery
What does the caudal vesical artery branch from?
Urogenital artery
What is the venous drainage of the bladder?
Internal pudendal vein
What is the blood supply to urethra?
branches of the internal pudendal arteries and veins (urethral, prostatic, penile).
What nerves innervate the bladder and urethra? (3)
- Hypogastric
- Pelvic
- Pudendal
What stimulates β-adrenergic receptors in the bladder wall resulting in detrusor muscle relaxation to allow storage of urine. It also stimulates α-adrenergic receptors in the bladder neck and proximal urethra, causing smooth muscle contraction, preventing urine flow.
Hypogastric nerve
What is stimulated by stretch receptors in the detrusor muscle when the bladder nears capacity and this initiates detrusor contraction. The stretch receptors also depress sympathetic outflow to relax smooth and striated urethral musculature.
Pelvic nerve
What provides somatic innervation to the periurethral striated muscle at the bladder neck (the external urethral sphincter). The muscle is normally in a steady state of contraction and is inhibited during urination?
Pudendal nerve
What are the indications for cystotomy? (6)
- calculi
- Biopsy
- Mass removals
- Repair of trauma
- Surgical treatment of ectopic ureters,
- Investigation of idiopathic renal haematuria
Where is the stay suture placed in the bladder in a cystotomy?
Apex
During a cystotomy which approach has a less risk of damaging the ureter opening?
Ventral
How is the bladder opened in a cystotomy?
A stab incision is made into approximately the midline of the ventral bladder using a scalpel, in an area of least vascularity
How is the cystotomy closeD?
one or two layers using a monofilament, absorbable suture material.
What layer should be involved in bladder closure - what should be avoided?
submucosa and avoid contact with the lumen of the bladder.
What suture material for bladder closure?
PDS (polydioxanone)
Monocryl (polyglecaprone)
What suture material for bladder closure if UTI present?
Long lasting monofilament
What type of bacteria would make you want you to choose a long lasting monofilament in bladder closure?
Proteus
How many layers to close bladder if thickened?
1
If a thin bladder wall - how to clsoe?
a 2nd inverting layer
What is the most common indication for a cystotomy?
Bladder and urethral calculi
Where is the most common location for urolith in cats/dogs?
Bladder
Urine pH, which crystals form in:
A) Alkaline
B) Acidic
A) Struvite
B) Calcium oxalate
What stone are english bulldogs pre disposed to?
Cystine
What stone are dalmations pre disposed to?
Urate
Which stone is more common in:
A) Female?
B) Male?
A) Struvite
B) Calcium oxalate
Which stones are more common with UTI?
urease-producing bacteria which increase the urine pH (struvite)
What uroliths are common with a PSS?
Urate
What urolith is common with hyperCa?
calcium oxlate
Which uroliths are found on plain radiographs?
Struvite
Calcium oxlate
What increases sensitivity of detecting uroliths rather than plain xray? (3)
pneumocystography
Double-contrast cystography
Ultrasonography
What is the radio-opacity of urate?
Radiolucent
How can hyperkalamia be treated? (2)
- IV Calcium gluconate
- IV soluble insulin + dextrose
When is tube cystotomy used?
When urinary diversion (stabilisation of an animal with lower urinary tract obstruction) or prevention of bladder distension is required.
Tube cystotomy steps.
- A caudal laparotomy is performed and the cystostomy tube is pulled through a stab incision in the body wall adjacent to the bladder.
- A purse-string suture is then placed in the bladder adjacent to the abdominal incision using monofilament absorbable
- A stab incision is made into the bladder in the centre of the purse-string, and the tip of the catheter is placed through this. If a Foley is used it should be inflated with the appropriate volume of saline to secure the tube within the bladder.suture material.
- The purse-string suture is tied, and three or four non-penetrating interrupted sutures are placed between the bladder and the body-wall (an omental flap can also be wrapped around the tube).
- The purse-string suture is tied, and three or four non-penetrating interrupted sutures are placed between the bladder and the body-wall (an omental flap can also be wrapped around the tube).
A dressing is placed over the tube’s exit point, and a string vest is applied.
What is a mini-invasive cystotomy tube?
Pigtail catheter
What are indications for partial cystectomy? (4)
- Patent urachus
- Bladder diverticulum
- Polyp
- Bladder necrosis
How operable is bladder neoplasa?
Some bladder neoplasia can also be treated by surgery but often the disease process is too advanced and total or near-total cystectomy (if surgery is considered) needs to be performed to allow clean margins.
Cystectomy often results in…
Incontinence
What disease process if the best case for partial cystectomy
Apex neoplasia
Defects created by partial cystectomy will regenerate via cells contained within the ..
Trigone
It is important to realise that any cystectomy that involves the resection of the trigone will:
A) what happens with ureter?
B) Bladder size?
A) require ureteral re-implantation (increasing the level of surgical difficulty);
B) have limited capacity of cell regeneration and will lead to a permanent small bladder.
Augmentation cystoplasty procedures have been described using ….
Vascularised portion of the gastrointestinal tract including jejunal reservoir and de-epithelialized ileum. It has also been described using colonic seromuscular layers.
Ureteric re-implantations after total cystectomy have been described in clinical cases in dogs. How? (both sex (1), male (1), female (2))
They can be done at the level of the skin,
Inside the prepuce or urethra in males
In vagina or uterus in females.
Why is ureter re implantation in the GI tract not used? (2)
- Reabsorping urine via villi
- Acid-base abnormalities
