115. Ureters Flashcards
define extra and intramural ectopic ureters
intramural-ureter enters the bladder wall at a normal anatomic position but a portion of the ureter extends submucosally within the bladder wall b4 entering urethra or vagina(large majority of EU in dogs are IM)extramural-ureter bypasses bladder completely to enter urethral lumen
how often are bilateral ectopic ureters diagnosed
bilateral EU occures in >1/3in dogs, the large majority of EU are intramuralin cats, majority of EU are extramurallook for other congenital abN (kidneys, vestibulovaginal)
4 types of EU
intramuralextramuraldouble ureteral openingsureteral troughs
list treatment techniques for intramural EU
neoureterostomy (new ureter stoma)ureteroneocystotomy (implantation of a resected ureter)cystoscopic guided laser ablationsalvage nephroureterectomy
list surgical techniques for extramural EU
ureteroneocystotomy (implantation of a resected ureter)salvage nephroureterectomy
what are two options to help bring the uretery to the bladder for a ureteroneocystostomy
renal descenus (caudally move kidney)psoas hitch (cranially move bladder)
normal ureter diameter
0.007x length L2 (canine)canine 2-2.5 mmfeline 0.5-1.0 mm
blood supply to ureters
ureteral artery ( branch from renal artery)ureteric branch of caudal vesicular artery (branch of vaginal/prostatic artery)
layers of the ureters
outer adventitia central muscular—smooth (inner and outer long, central circular)inner mucosa—transitional epith, microvili, mucinous coat
% return to normal function after 1 vs 2 weeks of obstruction
1 week obstructed—-65% returns after unobstruction2 weeks obstructed—46% returns after 4 months unobstruction
what is the most common reason for ureteral surgery in cats
feline obstructive ureterolithiasismed mgmt: diurese, glucagon (side effects), amitriptyline
1 and 2 year survival rates for cats tx with or without surgery for ureterolithiasis
without sx 66%, 66%with surgery 91% 88%Kyles JAVMA 2005
4 concepts to tell owners when discussing taking a cat to surgery for ureteroliths and obstruction
- every cat has a different amount of damage and we cannot predict what “rebound” or improvement in kidney function will be seen2. kidney biospies secondary to obstruction show some degree of chronic interstitial nephritis. This is progressive3. if a cat has unilateral stones but is azotemic, it must have bilateral kidney disease and removing stone will not cure it. 4. significant complications 33%, mortality 20%, most common complication uroabdomen 16%
options to relieve feline obstruction from ureterolithiasis
- ureteral R&A2. ureteral resection and reimplantation (ureteroneocystostomy)3. ureterotomy (uncommon)4. pyelolithotomy (if stones in renal pelvis and dilated)5. ureteral stent/double pigtail ureteral catheter6. subcutaneous ureteral bypass (SUBS)7. ureteronephrectomyif dog add ECSW lithotripsy for management of stones
ureteral catheter placement
surgical placement 80% success (retro or normograde)cystoscope placement 30% successdouble pigtail ureteral catheter (need guide wire and ureteral dilator)
treatment options for ureteral neoplasia
- ureteral R&A if margins are achievable2. ureteral resection and reimplantation (ureteroneocystostomy)3. ureteronephrectomy4. ureterocolonic anastomosis
ureteral injury associated with OHE
dogs > catscan lead to ureterovaginal fistulahydronephrosisureteral obstructiontx: ureteral resection and reimplantation or ureteronephrectomy
urinoma
collection of urine within the retroperitoneal space that causes fat necrosis and subsequent reactive fibrosismay occur from previous trauma
signalment for EU
—FEMALES 20x more likely than male—young (congenital abN)–urinary incontinence, positional–Skye Terriers, Labs
diagnosis of EU
—contrast radiography/fluoroscopy: IV excretory urogram 75% accurate, retrograde vaginocystography/urethrography (unreliable)–US: ureteral jets; SN 90—CT SN 90 SP 100—cystoscopy: eval other concurrent congenital abN, treat with laser, 100%
compare CT, excretory urography w fluoro and urethrography with fluoro for diagnosis of EU
CT superior90 SN 100 SPexcretory urography with fluoro (better than urethrography)80 SN 100 SP
outcome of incontinence following surgical repair for EU
10-60% resolution (outcome may be better in males and cats)recurrence may be from recanalization of distal ligation or undiagnosed abN urethral pressure profiles with functional abN of urethral, bladder, or both
ureterocele
dilatation associated with the distal ureter or ureteral orifice that occurs as a result of faulty embryonic development1. orthotopic2. intravesicularbilateral or unilateralcommonly associated with ectopic ureterstx: ureterocelectomy +/- repair of EU (resection and reimplant or neoureterostomy)
4 contraindications to IV pyelogram/excretory urethrogram
- urinary obstruction2. azotemia3. dehydration4. hypotension
traditional vs new nephrostomy tube placement
traditional red rubber nephrostomy tubes: 50% complicationspost op complications of uroabdomen was more common with traditional nephrostomy tubes 24% than without 12%pigtail nephrostomy tubes gained favor!
ureteral réimplantation techniques (ureteroneocystostomy)
end (ureter) to side (bladder) anastomosisintravesicular (mucosal apposition–avoid “drop in” technique bc risk granuloma and obstruction) requires ventral cystotomyextravesicular suture ureter to bladder with knots external to lumen
tension reduction for ureteral resection and implantation
–renal descensus (nephropexy caudally)–psoas hitch (cystopexy cranially)
prognosis in cats with obstruction ureterolithiasis based on Kyles et al JAVMA 2005
uroabdomen–the most common complicationno difference in ureterotomy vs ureteroneocystostomy for occurrence of uroabureterocystostomy (ureteral resect/reimplant) had more persistent ureteral obstruction than ureterotomycomplications 33%mortality 20%
neoureterostomy for tx for intramural EU
side to side anastomosisventral cystotomy (nice to have ureter catheter in place from cystoscopy)ligate distal ureter from outside/dorsal bladder wall (non absorbable–keep suture out of lumen)create new stoma and suture ureteral and bladder mucosa (absorbable)
T/Fthere is a difference in urethral trigone reconstruction vs ligating distal intramural ureter for the treatment of intramural ectopic ureters
FALSE NO DIFFERENCE IN TECHNIQUES43% of both groups were still incontinent after surgery and med mgmt (Mayhew JAVMA 2006)
% of cats with concurrent nephroliths (left behind at the time of ureterolith removal) that reobstructed
40%nephrolith migration possible but morbidity of nephrotomy at time of ureterolith surgery must be weighed before nephrotomy to remove kidney stones
normal cat kidney function after nephrotomy
10-20% reduction in GFR of NORMAL cats following nephrotomy
