Urinary surgery

Question 1

where do stones tend to lodge in males

Answer 1

near the os penis

Question 2

what type of emergency is urethral obstruction? what do we need to do quickly?

Answer 2

• MEDICAL, not surgical
  §Unblock: catheterize +/- retropulse stones
  § Rehydrate
  §Correct metabolic and elecrolyte imbalances

Question 3

should we try to remove stones as soon as possible in all cases of obstruction

Answer 3

Don’t get greedy in unstable sick patients!!!
§If you managed to pass a difficulty catheter in an unstable patient, don’t get greedy and take what you can get even if not ideal
§Stabilize the patient before attempting to retropulse the rest of the stones in case you are unable to catheterize again

Question 4

use of radiographs for Dx of urethral obstruction

Answer 4

§Radiographs (radioopaque stones) are recommended to assess the location, size and approximate number of calculi prior to surgery
§Contrast study / US for radiolucent stones

Question 5

Hydroretropulsion - what is this, purpose / use for urethral obstruction

Answer 5

“Hydroretropulsion’
= Retrograde saline flush > return calculi into the bladder
Because:
§Cystotomy is easier than urethrotomy
§Less complications than with urethral surgery
§Urethrotomy only if cannot dislodge stones (very rare procedure)

Question 6

how to perform a hydroretropulsion - what equipment do we need

Answer 6

§20 or 30 cc syringe
§Aqueous lubricant & saline
(not sterile water -> tissue swelling)
§Lidocaine (gel or solution)
§Urinary catheter (flexible not stiff)
§Sedation : opioid + diazepam
§Assistant + gloves + lubricant (rectum)
§Empty the bladder before retropulsing and every 1-3 syringes
§GA +/- epidural might help

Question 7

risk of using a rigid / stiff catheter for urethra

Answer 7

more likely to cause rupture

Question 8

after hydroretropulsion, how long should we leave catheter in place? should we do a cystotomy right away?

Answer 8

§Leave urinary catheter in place
until cystotomy to prevent stones from re- entering the proximal urethra when animal is placed in dorsal recumbency for surgery
§Cystotomy as soon as feasible if animal is stable and it’s not the middle of the night
§Cystotomy later if animal is sick and uremic and would benefit from stabilization
> Fluid therapy is most important
> Urine drainage via u-catheter

Question 9

should we keep a urinary catheter in place during a cystotomy? why?

Answer 9

§Urinary catheter left in place to prevent stones returning to urethra and to allow intra-op retrograde urethral flushing

Question 10

indications for cystotomy other than stones

Answer 10

§Cystic / mass biopsy
§Ureteral catheterization
§Surgical correction of extra mural ectopic ureters

Question 11

principles of cystotomy - how to perform: approach, incision, considerations…

Answer 11

§ Caudal midline celiotomy (parapreputial in male dogs)
§ Ensure adequate lenght incision in abdomen and bladder
§Evaluate the entire accessible urinary tract
§Prevent abdominal spillage / contamination
> Urine is typically sterile but not always when there are stones
§Perioperative antibiotics
> Cefazolin 22mg/kg, 30 minutes prior to surgery and q90 mins intraop
> No difference in culture results when ATBx given at anesthetic induction versus after surgical culture sample collection (Buote et al. 2012) so don’t delay until after culture
> Continue postop only if known or suspected infection / known abdominal contamination and adjust based on culture postop

Question 12

is dorsal or ventral incision reccomended for cystotomy? why?

Answer 12

Ventral Recommended:
§Decreases risk of damaging ureteral openings (as they enter dorsally into the bladder)
§Easier to perform
§Provides better visualization of neck and trigone (not kinked over)
§Facilitates retrieval of calculi
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Dorsal should NOT be done:
§Does not minimize post-op leakage b/c incision on roof
§Is not less calculogenic (sutures still bathe in urine)
§Does not result in fewer abdominal wall adhesions
§High risk of ureteral trauma / incorporation in suture line…

Question 13

should we make cystotomy incision at apex of bladder?

Answer 13

no, too far from trigone where stones like to sit
- go closer to trigone, but without interfering with ureters

Question 14

cystotomy
where does the ventral ligament of the bladder attach? should we cut it? where, and why?

Answer 14

Ventral ligament – attaches to linea alba (on one side)
- Cut it close to the bladder – guides your incision site on ventral wall and removing helps closure, especially if it contains fat

Question 15

cystotomy
lateral ligament of bladder - what structures contained within? should we cut it?

Answer 15

Lateral ligament – contains ureter, vessels, nerves and fat – stay away!!

Question 16

cystotomy
where can we place stay suture? how do they help?

Answer 16

Place a stay suture at the apex to facilitate retraction and manipulation +/- another close to the trigone
(take your bite lengthwise in case of tearing to allow easier closure)
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Additional stay sutures can be placed on either side of the proposed incision or added after incising the bladder to facilitate stone retreival

Question 17

cystotomy
what can we do to help prevent abdominal contamination?

Answer 17

Pack the abdomen with moistened laparotomy sponges to prevent contamination during cystotomy

Question 17

cystotomy
should we pack abdomen with sponges first, or place stay sutures first? why?

Answer 17

Place stay sutures prior to packing and ensure you still have access to the trigone since you don’t want the incision purely at the apex of the bladder

Question 18

cytotomy
how can we deal with a full bladder?

Answer 18

The bladder can be drained prior to incising or the urine absorbed using suction or lap sponges during / after incision

Question 19

cystotomy
where do we incise?

Answer 19

• Make a stab incision on ventral midline (full thickness)
• Try to avoid large vessels

Question 20

cystotomy
where do we incise?

Answer 20

• Ensure you open close to / over the trigone but not into the urethra
• Extend the incision with scissors to a sufficient length

Question 21

cystotomy
- how to retrieve stones?
- how to improve visualization?

Answer 21

• Suction urine (if you have access) and retrieve the stones using forceps, bladder spoons, etc.
• can use carmalt to spread incision to improve visualization

Question 22

cystotomy
- intraoperative retropulsion using preplaced catheter
> how do we do this?

Answer 22

• RETROGRADE catheter flush with saline usually after removing all the stones already present in the bladder
  § Retropulsion while slowly retracting the catheter
  § Using sterile saline but performed by an unsterile assistant who crawls under the drapes or by the surgeons if a sterile catheter is maintained within the field (easier in males than females)
  § The catheter is slowly removed (1cm at a time) while lots of saline is pulsed under pressure into the catheter
  § The surgeon watches for stones being retropulsed into the bladder and removes them as they appear (pausing retropulsion each time)
  § Normograde flush ? (females & small stones only to prevent obstruction in distal urethra / os penis)

Question 23

cystotomy closure
- pattern?

Answer 23

§ Simple continuous including entire wall thickness (difficult not to include mucosa in thin-walled bladder)
> + /-Lembert or Cushing
(oversew in seromuscular)
> personal preference
> Not always possible in thick-walled/ very inflamed bladders
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- stretch out bladder to suture, make sure sutures are tight
- (Brisson prefers 2 layer closure in the right instance)

Question 24

cystotomy closure - type of suture used, types not to use, considerations

Answer 24

§3-0 or 4-0 absorbable monofilament suture on a curved, swaged, taper needle
§Polyglecaprone 25 (Monocryl) is ideal
§No catgut or polyglycolic acid (Dexon®) (especially
in infected urine) because it dissolves too soon
§Biosyn® and PDS® take a long time to be resorbed and might be calculogenic (suture nidus)

Question 25

tips for bladder closure in cystotomy

Answer 25

§ Ensure the bladder is well stretched (use your stay sutures / trail your suture line tightly) while closing to prevent the suture bites from being too far apart (the bladder shrinks when empty but will fill and stretch and thin out when it fills– misleading when empty unless stretched during closing)
§ Trail the suture tightly to prevent a loose suture line that leaks…