LUT Surgeries Flashcards
describe the blood supply and innervation of the bladder
blood supply: cranial and caudal vesicle artery
innervation:
-pelvic n: parasympathetic
-hypogastric: sympathetic, increase capacity
-pudendal: somatic, ext sphincter
-don’t really see nerves bc running dorsally (we don’t usually operate on this side; ventral is safer!)
describe the ligaments of the bladder
- lateral ligaments: innervation, blood supply, ureters; can be very fatty
- median ligament: nice landmark for ventral midline
describe the surgical approach for cystotomy
- caudal ventral midline incision in females
-nice and easy - preputial in males:
-prepuce contains: preputial muscle, ligament, and vein (have to ligate bc its so big)
-also branches of caudal superficial epigastric vessels
-ligament can be so thick can look like body wall!
describe the principles of bladder surgery
- pack off abdomen
- stay sutures to manipulate bladder (don’t want to grab bladder over and over)
- aspirate urine/use suction
- catheterize the urethra
- monofilament, absorbable suture to close bladder
- one layer versus two
- holding later in the SUBmucosa
- leak test
where should you make your cystotomy: dorsal or ventral?
ventral apex is perfect! puts you farthest away from ureters
fears: gravity causing leakage, adhesions, stones
-but pressure spreads out the force so there is equal risk of leakage
-no difference in adhesions, use omentum
-absorbable suture decreases the risk of stones greatly
dorsal cystotomy puts the hidden course of the intramural ureter at risk
-calculi roll down into urethra and are much easier to access with ventral cystotomy
describe evaluation of the urethra after removing stones from the bladder
- in males: pass a catheter retrograde first to flush additional stones into the bladder
- then flush normograde
-usually only flush normograde in a female dog, not retrograde bc vulva not usually in surgical field like penis in males - repeat several times
- evaluate the stream and the feel of the catheter
what do you do at the end of a cystotomy before you start to close?
make sure ALL stones are out!! palpate
describe sample submission related to cystotomy
- bladder mucosa: best culture
- stones: analysis and culture
-should always do if remove stone! - bladder wall: histopathology (less common)
describe single versus double layer closure of bladder
- surgeon’s preference: bladder usually heals pretty well regardless of what you do
- either way, holding layer is SUBmucosa!!
- options:
-full thickness simple continuous (most common)
-interrupted
-2 layers of simple cont
-simple cont with and inverting oversew - small bladders: 1 layer, minimal or no inverting
-inverting: benefits are better seal, but also reduce volume of bladder (disadvantage)
what should you always do post-op cystotomy and why?
take radiographs!! want to verify that you removed all stones and also for proof (CYA) if owner doesn’t comply with management and dog develops more stones
describe urethrotomy versus urethrostomy
urethrotomy: make a hole and close it
-typically when stone in urethra
urethrostomy: make hole and leave it open
describe scrotal urethrostomy
- indications: almost exclusively in male dogs for:
-distal urethral obstruction
-in conjunction with penile amputation
describe urethral obstruction in dogs
- most commonly due to cystic calculi displaced into the urethra
- urethra in male dogs limited in distensibility at the os penis
- stones tend to lodge in caudal margin of os penis!
- complete urinary tract obstruction is always an emergency; delayed treatment can result in severe bladder damage, distension atony, and uremia
- cystotomy is always preferred whenever possible!
-easier to manage, less prone to complications
-every attempt should be made to retropulse urethral stones back into the bladder and remove them via a cystotomy - if unable to move stones to alleviate obstruction, will need to remove via urethrotomy
-in instances where continued stone formation is expected or if penile amputation is performed, a permanent urethrostomy may be a good choice
describe urethrotomy method
- nearly always in the prescrotal area just behind the os penis
- in dogs, a perineal urethrotomy or urethrostomy is rarely required and can cause urine scald on caudal thighs
-unlike cats, which almost always have a perineal urethrostomy (are already used to peeing backwards) - incise skin and subcutaneous tissue over stones in the prescrotal area
-minimize any lateral dissection (ideally none)
-continue incision down to retractor penis muscle
-retractor penis may be undermined and retracted laterally or incised on ventral midline
describe closure of urethrotomies
- can be left open!! heal by second intention
-risk: even more stricture at this spot = not great option - urethrotomy incisions can be closed if tussue is healthy: 5-0,6-0 absorbable suture
- urethral incisions are prones to urine leakage; may need to leave a U cath in for several days
- if urine entrapped in SQ layer, substantial tissue necrosis will occur
- if left open, incisions will have bleeding from the urethral submucosal vascular plexus for several days to even weeks
- a compromise solution is to close urethra but leave overlying tissue wound open to heal by second intention
-prevents urine entrapment in tissue but reduced hemorrhage from urethrotomy
