Chapter 116 Bladder Flashcards
What structures are contaned in lat lig of bladder
Ureters and umbilical arteries
When bladder is fully distended, if part is in pelvic canal, how is this interpreted?
And in cat
Can be nornal in dogs
Abnormal in a cat - should always be intraabdominal
What are the margins of the trigone
Between ureteral openings and in dorsal bladder wall and proximal urethral opening
What type of epithelium is in the bladder
Transitional
Describe the innervation of the bladder
Sympathetic:
- Except for during micturition, the smooth muscle at the vesicourethral junction is maintained in a steady state of contraction by sympathetic stimulation of α-adrenergic receptors in the bladder neck and proximal urethra via the hypogastric nerves. Sympathetic hypogastric nerve stimulation of β-adrenergic receptors in the bladder wall simultaneously relaxes the detrusor muscle, allowing storage of urine. The preganglionic branches of the hypogastric sympathetic nerves originate from the thoracolumbar spinal cord.
Parasympathetic:
- When the bladder nears its capacity, stretch receptors are activated by distention of the detrusor muscle, resulting in parasympathetic pelvic nerve stimulation that initiates reflex detrusor muscle contraction and subsequent urination. Activation of the stretch receptors in the bladder wall also depresses sympathetic outflow and acts on the brainstem to cause relaxation of smooth and striated urethral musculature, permitting urination.
- The parasympathetic pelvic nerves originate in the sacral spinal cord (S1 to S3) and pontine micturition center. Integration in the brainstem is necessary for the detrusor reflex to be coordinated and sustained long enough for bladder evacuation.
- Not all detrusor muscle cells have direct innervation: transmission of neuromuscular impulses also occurs between one innervated detrusor muscle cell and many adjacent muscle cells.Prolonged bladder distention or bladder fibrosis results in loss of this excitation-contraction coupling; subsequent atony of the detrusor muscle results in urine retention and overflow.
Somatic:
- The pudendal nerve originates in the sacral spinal cord (S1 to S3) and provides somatic innervation to the periurethral striated muscle at the bladder neck (external urethral sphincter).
- The external urethral striated muscle, similar to the smooth muscle in this region, remains in a state of steady contraction, contributing to active urethral resistance during urine storage, and is inhibited during reflex urination.
- Additionally, voluntary control can initiate or inhibit the detrusor reflex so that micturition occurs at an appropriate time and place. Voluntary control of micturition occurs via the somatic pudendal nerve innervation of striated urethral musculature and direct cortical innervation of the pontine micturition center.
All of the innervation to the bladder merges together at the pelvic plexus before entering along the dorsal surface in the region of the bladder neck. There are multiple synaptic connections between the nerves at this level, which facilitates the complex coordination of innervation that is required for maintenance of continence and micturition.
What it the main blood supply to the bladder?
Caudal vesical
(Branch of vaginal/prostatic artery which is branch of internal pudendal)
Cranial vesical is end of umbilical artery which may or may not persist in adult dog. If it does then it supplies cranial bladder
Label the diagram (top is male, bottom female)
WHat LNs drain bladder
Sublumbar and internal iliac
How quickly dobaldder mucosal defects heal?
How long until bladder has reached full pre-sx strenght?
5d
14-21d until full strenght
Which suture material(s) are acceptable in ecoli infected urine?
Which is not ok?
Which is best in proteus infected urine?
Polydioxanone (PDS) and polyglyconate (Maxon) ok in E coli
Poliglecapreone 25 not ok in ecoli urine
PDS best in proteus (but all 4 disintegrated in <7d in proteus)
How can a bladdder repair be augmented
Outer inverting pattern
Omentum
Serosal patch
What pH does struvite usually occur in
Alkaline
Which uroliths are usually not visible on radiographs
Cystine and urate
Which uroliths are amenable to medical dissolution
Struvite, cystine, urate
What is usual appearwnce of silica uroliths
Jackstone
Why is struvite urine usually alkaline
Urease-producing bacteria (e.g., Staphylococcus or Proteus spp.) split urea to ammonia and carbon dioxide; hydrolysis of ammonia then results in alkalinized urine, which decreases struvite solubility)
What imaging method is recommended for highligting
Double contrast urethrocystogram (dont do if bladder rupture - risk of fatal air embolism)
Name 2 methods for obtaining non-invasive bladder bx
US guided transcatheter (US guided grab biopsy via catheter also described)
Cystoscopic guided grab biopsy
3 methods for cystoscopy in make dog
- Flexible scope transurethrally (i.e. from penis)
- Rigid via percutaneous perineal approach
- Rigid via prepubic percutaneous approach
What is % of risk or uroabdomen after cystotomy
<1.5%
How does the bladder regenerate after cystectomy (histologically speaking)?
- mucosal regeneration
- synthesis and remodeling of scar tissue
- hypertrophy and proliferation of smooth muscle
- distention of the remaining bladder wall
What is important when considerign regenerative ability of bladder and why?
After 10 months dogs had regained full bladder capacity after what % cystectomy
Leaving trigone intact because regenerating cells arise from epithelium of terminal ureters and urethra
30-40% (i.e. this is well tolerated, but 90% cystectomy –> persistent 72% reduction in capacity 9 months post-op)
List 4 methods for management of massive bladder necrosis
- Enterocystoplasty
- Seromuscular colonic colonic augmentation
- Porcine SIS
- Total cystectomy and ureteric re-implantation into prepuce, vagina, cutaneous, urethra, (colon but not recommended)
- (rectus abdominis also used to augement bladder neck and proximal urethra necrosis)
How long does cystostomy tube hve to be in place before ok to remove?
7 d
What is complication rate with cystostomy?
49%
(inadvertent tube removal or displacement from the bladder, animal chewing the tube, breakage of the mushroom tip during removal, fistula formation after tube removal, urine leakage around the tube, rectal prolapse secondary to straining associated with the presence of the tube, inflammation around the tube exit site, hematuria, inadvertent removal of the urine collection bag, tube obstruction, bandage sores, and breakage of the suture anchoring the tube to the skin.10 Most complications were easily resolved, but 2/76 animals were euthanatized because of cystostomy tube complications)
List 5 possibel congenital bladder anomalies
- vesicourachal diverticula
- patent urachus
- bladder hypoplasia
- genitourinary dysplasia in cats
Even rarer congenital anomalies include
- trigone diverticula
- bladder inversion
- bladder agenesis
- bladder exstrophy
- urachal cyst
- urinary bladder duplication
- colocystic fistula
What other condition usually occurs with bladder hypoplasia?
Ectopic ureters
How is vesicourachal diveeticulum managed
Only address if clinical = partial cystectomy
Ina study of 100 dogs with pelvic fracture, how many had concurrent urinary tract rupture
16/100
What is an option for emergency stabiliztion in a uroabdomen animal (aside form the usual)
Peritoneal dialysis by instillign warm saline into abdo drain (initially 20 ml/kg) allow to equilibrate then drain and repeat, until volume in is = volume out
What % of dogs with cystolith had UTI
76%
List 6 methods for cystolith retrieveal
- catheter-assisted retrieval (if v small)
- transurethral cystoscopic retrieval
- voiding hydropropulsion
- lithotripsy
- laparoscopic-assisted or percutaneous cystotomy
- surgical cystotomy
What type of laser is used for lithotripsy
Ho:Yag
Holmium: Yttrium-Aluminium-Garnet
In what % od cases is urolith removal incomplete
20%
How is urine spillage minimised during percutaenous cystotoym (ie minimally invasive cystotomy) (3 points)
- Pursestring in bladder prior to trocar insertion
- Pack with swabs
- Use a trocar with a diaphragm/valve
What were results of stdy comparing open sx vs lap-assisted cystotomy?
Lap assisted:
- Slower
- More expensive
- Less post-op analgesia necessary
- No difference in duration of hospitalisation (unlike lithotrispy which –> shorter hospitalistion)
- No difference in completeness of cystolith removal
How can recurrent cystine calculi be managed?
Dietary initially but if necessary
2-MPG prevented recurrence in 86% of dogs
Ddx
- Polypoid cystitis (this is what it is)
- Malakoplakia (=chronic granulomatous tissue)
- TCC
- Lymphoma
- HSA/haemangioma
- Rhabdomyosarcoma
- Adenocarcinoma
- Leiomyoma/myosarcoma
- Fribroma/-sarcoma
List 3 surgical options for polypoid cystitis
- Partial cystectomy
- Submucosal resection
- Excisional biopsy using clamp across base
- Lap assisted cystoscopy
What is neoplasia affecting bladder of young (<2 yr) large breed dogs
Embryonal rhabdomyosarcoma
Where is most common site for urinary tract neoplasia in dogs?
And in cats
Bladder in dogs
renal (lymphoma) in cats
List 5 factors associated with TCC development
- feale
- Obesity
- Use of older types of topical insecticides
- Exposure to phenoxy herbicides
- Nitrosamine exposure
- Cyclophosphamide exposure
- Living in area of high industrial activity
What region if typically affected by polypoid cystitis
Cranioventral bladder
(Usually occurs in females)
What is a non-sx test for dx of bladder TCC
Urine antigen test (but not v accurate)
In what % of cases did US guided transurethral biopsy correctly diagnose TCC in male dogs?
And female dogs?
65% male dogs
96% female dogs
What is typical management of TCC
NSAID
and chemo
Chemo cwitched when one becomes ineffective - no evidence to show that ,utlimodal imroved outcome andmore liekly to lead to s/e and resistance
Woody Marr was managed with carboplatin, then vinblastine then chlorambucil
What drug has been used for metronomic chemo for bladder TCC
Chlorambucil
List 2 surgical options for palliation of bladder neck TCC
- Cystostomy tube
- Urethral stent (1/3rd –> incontinence)
- Transurethral cystoscopic laser
- Excision of bladder neck inc trigone and urethra reported
- (Circumferential excision of the bladder neck and proximal urethra with preservation of the neurovascular pedicles was performed to remove a rhabdomyosarcoma (dog 1) and a transitional cell carcinoma (dog 2) involving the trigone and bladder neck that were causing urinary tract obstruction. Reconstruction of the bladder and proximal urethra included bilateral ureteroneocystostomy.)
In dogs, diagnosis of uroabdome canbe made with 100% sens and spec if 2/3 criteria re effusion are met - what are the criteria
- Effusion K > 1.4x serum K
- Effusion creat > 2x serum creat
- Effusion creat > 4x upper reference interval for serum creatinine
