116.Bladder Flashcards
ligaments and layers of the bladder
LIGAMENTS—ventral median ligament (urachus remnant)–lateral ligaments (fat, distal ureter, umbilical artery)LAYERS—transitional epith cell mucosa (mucosa and submucosa make up urothelium)–submucosa—smooth muscle detrusor m–serosaNO ANATOMICAL INTERNAL URETHERAL SPHINCTER—just blending of detrusor with smooth muscle of urethra
innervation to bladder and micturition reflex
SNS (storage)—hypogaStric (in TL cord)alpha–neck and proximal urethra (active–contract)beta–detrusor muscle (inhibit—relax)—when bladder fills, stretch receptors on muscle activate to stimulate PSNSPSNS (Peeing)–Pelvic (sacral and pontine micturition center)inhibit beta—causes detrustor muscle to contractinhibit alpha–causes bladder neck and prox urethra to relaxinhibit somatic pudendal nerve Somatic (voluntary)–Pudendal nerve (sacral)acts on striated urethral musculature (external urethral sphincter) to contract for urine retention and relax for voluntary micturitionall innervation to bladder merges together at the pelvic plexus on the dorsal surface of the bladder
blood supply to the bladder
internal iliac–> umbilical artery–> cranial vesicular arteryinternal iliac–>internal pudendal—> vaginal–>middle rectal, uterine, urethral, caudal vesicular artery internal iliac–>internal pudendal–>prostatic–>middle rectal, ductus deferens branch, urethral, caudal vesicular artery
tissue strength regained during wound healing
mucosal defects fill in 5 days100% strength in 14-21 days
reported rate of suture associated cystoliths
10% dogs 4% catsunknown suture material usedrecommend monofilament absorbable, taper pointsubmucosal holding layer
suture recommendations in canine sterile urine or urine inoculated with E.coli vs Proteus
polydiaxanone and polyglyconate are acceptable for canine urine (sterile or w Ecoli) but poliglecaperone may NOT have sufficient tensile strength ALL the tested sutures dissolved before day 7 in Proteus infected urine
treatment for hyperkalemia in urinary patients before anesthesia
–fluid diuresis (NaCl) but may need to supplement K in post obstructive diuresis period, monitor–relieve obstruction (cysto, catheter)–temporary urine diversion—calcium gluconate if brady cardia–insulin, dextrose, NaBicarb therapy
diagnostics for bladder
—PE, RECTAL—CBC, Chem, UA—cystocentesis (blind or US guided)—abdominal rads—positive or double contrast cystourethrograms (rads or fluoro)–needed to ID intraperitoneal rupture–IV excretory urogram if urine leakage is retroperitoneal–abdominal US (SN for stones and wall lesions)–Catheter biopsy–cystoscopy +/- interventional techniques (bx, culture, stone retrieval, polyp removal)—laparoscopic assisted cystoscopy/cystotomy
diseases of the bladder
—neoplasia–urolithiasis–bladder diverticula–polypoid cystitis–idiopathic renal hematuria–ectopic ureters–cystitis/urethritis–urethral strictures–trauma/rupture
indications for cystotomy
—bladder mass resection–repair ectopic ureters–stone retrieval–biopsy culture for severe cystitis–investigate idiopathic renal hematuria—repair bladder traumaalways consider biopsy and culture of MUCOSA!
T/Fthere is no difference in the likelihood of urine leakage, adhesions, or calculi formation btwn dorsal and ventral cystotomy approaches
trueventral is easier and decr risk of iatrogenic damage to ureters
indications for cystectomy
–bladder neoplasia–necrotic wall from trauma–bladder diverticula–patent urachus* if a lot of bladder is removed, may need temporary urine diversion; if removal of tissue near ureters, may need to reimplant
bladder regeneration after cystectomy
–mucosal regeneration–synthesis–remodeling of scar–hypertrophy and proliferation of smooth muscle–distension of remaining bladder wallTRIGONE is key for bladder regeneration bc the regeneration cells arise from the epithelium of the terminal ureters and urethracan excise a lot–even 75% if trigone intact—biggest complication may be pollakuria, none were incontinent
what to do if cystectomy is expected to exceed the ability to close the bladder wall safely
–seromuscular colonic augmentation (exterior wall of colon became cranial wall of bladder)–ileocystoplasty–rectus abdominus muscle flap—SIS in 40% cystectomy model (not 90%)consider temporary urinary diversion
indications for cystostomy tube
TEMPORARY–diversion of urine due to extensive cystectomy—diversion of urine due to trauma (with or without repair)—relieve obstructionPERMANENT–palliative for neoplasia obstruction–bladder atony (neurogenic)Use: Mushroom Tip (dePezzer) or low profile gastrostomy tubes (silicone)must keep in for 7 days to allow stoma to heal
complications associated with tube cystostomy
50%–inadvertant tube removal–kinking/obstruction–animal mutilation–tube breakage–stoma inflammation, infection–UTI (biofilm, residual urine)–uroabdomen–urine leakage at stoma
methods of cystopexy
–tube cystopexy–incisional cystopexy–lap assisted cystopexyseromuscular and submucosal layers of bladder to the transversus abdominus
the most common site of urinary tract rupture following trauma
BLADDER100 dogs with trauma with pelvic fractures—16 had urinary tract rupture
diagnosing uroabdomen on abdominocentesis
–cytology (look for bacT)–creatinine in fluid > 2.4 x serum–K in fluid > 1.4 x serum
dose for perionteal dialysis
20 ml/kg
majority of canine and feline uroliths
—struvite (magnesium ammonium phosphate)–forms in alkaline, associated with UTI, small female dogsrecur 21%–calcium oxalate–forms in acidic to neutral pH, male cats and dogs, very radio opaque, causes hyperCa, metabolic acidosis, acidifying diets (those used to treat struvite stones)usually STERILE in cats
percentage of idiopathic hyperCa patients that also have calcium oxalate urolithiassis
35%
methods for retrieval of calculi from the bladder
–cystotomy–cystoscopy (transurethral)–laparoscopic assisted cystotomy—voiding urohydropropulsion–catheter assisted retrieval–lithotripsy (Ho: YAG)–female dogs best candidate
reported incomplete removal Grant et al JAVMA 2010
20% incomplete removaldogs with both urethroliths and urocystoliths were more likely to have failed cystotomy
location preference for polypoid cystitis vs neoplasia in the bladder
neoplasia—trigone polypoid cystitis—cranioventral
malignant tumors of the bladder
bladder is most common location of canine urogenital tract neoplasia—TCCbladder is the SECOND most common location of FELINE urogenital tract neoplasia—RENAL LSA (is #1)both very malignant, staging important
therapy recommendations for TCC
–total cystectomy or wide partial cystectomy –associated with high morbidity and never curative alone (histolopathological tumor free margins are unlikely)–palliative cystostomy tubes–palliative urethral stunting if obstructed–chemo (mitoxantrone) plus piroxicam 300 days with 180 days with NSAID alone–radiation therapy has no role, poor local tumor control and serious side effects
if you had to list methods for surgical treatment of TCC
–partial cystectomy and primary closure–partial cystectomy with rectus abdominus, SIS, ileocystoplasty, or seromuscular colonic augmentation–total cystectomy with ureterouterine diversion–total cystectomy with ureterocolonic diversion–tube cystostomy (palliative)surgery alone is never curative and histopathological tumor free margins are unlikely; hi morbidity
