115. Ureters

Question 1

define extra and intramural ectopic ureters

Answer 1

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

Question 2

how often are bilateral ectopic ureters diagnosed

Answer 2

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)

Question 3

4 types of EU

Answer 3

intramuralextramuraldouble ureteral openingsureteral troughs

Question 4

list treatment techniques for intramural EU

Answer 4

neoureterostomy (new ureter stoma)ureteroneocystotomy (implantation of a resected ureter)cystoscopic guided laser ablationsalvage nephroureterectomy

Question 5

list surgical techniques for extramural EU

Answer 5

ureteroneocystotomy (implantation of a resected ureter)salvage nephroureterectomy

Question 6

what are two options to help bring the uretery to the bladder for a ureteroneocystostomy

Answer 6

renal descenus (caudally move kidney)psoas hitch (cranially move bladder)

Question 7

normal ureter diameter

Answer 7

0.007x length L2 (canine)canine 2-2.5 mmfeline 0.5-1.0 mm

Question 8

blood supply to ureters

Answer 8

ureteral artery ( branch from renal artery)ureteric branch of caudal vesicular artery (branch of vaginal/prostatic artery)

Question 9

layers of the ureters

Answer 9

outer adventitia central muscular—smooth (inner and outer long, central circular)inner mucosa—transitional epith, microvili, mucinous coat

Question 10

% return to normal function after 1 vs 2 weeks of obstruction

Answer 10

1 week obstructed—-65% returns after unobstruction2 weeks obstructed—46% returns after 4 months unobstruction

Question 11

what is the most common reason for ureteral surgery in cats

Answer 11

feline obstructive ureterolithiasismed mgmt: diurese, glucagon (side effects), amitriptyline

Question 12

1 and 2 year survival rates for cats tx with or without surgery for ureterolithiasis

Answer 12

without sx 66%, 66%with surgery 91% 88%Kyles JAVMA 2005

Question 13

4 concepts to tell owners when discussing taking a cat to surgery for ureteroliths and obstruction

Answer 13

1. 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%

Question 14

options to relieve feline obstruction from ureterolithiasis

Answer 14

1. 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

Question 15

ureteral catheter placement

Answer 15

surgical placement 80% success (retro or normograde)cystoscope placement 30% successdouble pigtail ureteral catheter (need guide wire and ureteral dilator)

Question 16

treatment options for ureteral neoplasia

Answer 16

1. ureteral R&A if margins are achievable2. ureteral resection and reimplantation (ureteroneocystostomy)3. ureteronephrectomy4. ureterocolonic anastomosis

Question 17

ureteral injury associated with OHE

Answer 17

dogs > catscan lead to ureterovaginal fistulahydronephrosisureteral obstructiontx: ureteral resection and reimplantation or ureteronephrectomy

Question 18

urinoma

Answer 18

collection of urine within the retroperitoneal space that causes fat necrosis and subsequent reactive fibrosismay occur from previous trauma

Question 19

signalment for EU

Answer 19

—FEMALES 20x more likely than male—young (congenital abN)–urinary incontinence, positional–Skye Terriers, Labs

Question 20

diagnosis of EU

Answer 20

—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%

Question 21

compare CT, excretory urography w fluoro and urethrography with fluoro for diagnosis of EU

Answer 21

CT superior90 SN 100 SPexcretory urography with fluoro (better than urethrography)80 SN 100 SP

Question 22

outcome of incontinence following surgical repair for EU

Answer 22

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

Question 23

ureterocele

Answer 23

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)

Question 24

4 contraindications to IV pyelogram/excretory urethrogram

Answer 24

1. urinary obstruction2. azotemia3. dehydration4. hypotension

Question 25

traditional vs new nephrostomy tube placement

Answer 25

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!

Question 26

ureteral réimplantation techniques (ureteroneocystostomy)

Answer 26

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

Question 27

tension reduction for ureteral resection and implantation

Answer 27

–renal descensus (nephropexy caudally)–psoas hitch (cystopexy cranially)

Question 28

prognosis in cats with obstruction ureterolithiasis based on Kyles et al JAVMA 2005

Answer 28

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%

Question 29

neoureterostomy for tx for intramural EU

Answer 29

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)

Question 30

T/Fthere is a difference in urethral trigone reconstruction vs ligating distal intramural ureter for the treatment of intramural ectopic ureters

Answer 30

FALSE NO DIFFERENCE IN TECHNIQUES43% of both groups were still incontinent after surgery and med mgmt (Mayhew JAVMA 2006)

Question 31

% of cats with concurrent nephroliths (left behind at the time of ureterolith removal) that reobstructed

Answer 31

40%nephrolith migration possible but morbidity of nephrotomy at time of ureterolith surgery must be weighed before nephrotomy to remove kidney stones

Question 32

normal cat kidney function after nephrotomy

Answer 32

10-20% reduction in GFR of NORMAL cats following nephrotomy