Chapter 116: Bladder

Question 1

The lateral ligaments of the bladder attach the bladder to the pelvic walls. What do they contain?

Answer 1

Fat, the distal portion of each ureter, and the umbilical artery on each side.

Question 2

Which nerve innervates the vesicourethral junction to keep it in a constant state of contraction, except at micturition?

Answer 2

The hypogastric nerve (from TL spine) via alpha receptors

sympathetic = store IMPORTANT

Question 3

Which nerve innervates the periurethral striated muscle at the bladder neck - a.k.a. the external urethral sphincter?

Answer 3

The pudendal nerve (spinal nerves S1-S3)

Parasympathetic = pee IMPORTANT

Question 4

Which artery is the major blood supply to the bladder?

Answer 4

Caudal vesicular artery (arising from vaginal or prostatic branch of the internal pudendal artery) IMPORTANT

Cranial vesicular may supply the cranial bladder.

Question 5

What veins drain the bladder?

Answer 5

Internal pudendal veins

Question 6

How many days does it take for a mucosal defect in the bladder to heal?

How many days to 100% normal tissue strength?

Answer 6

5 days

14-21 days to 100%

Question 7

What is the infection rate for cystotomies when there is no concurrent UTI?

Answer 7

5%

Question 8

How much of the bladder can feasibly be removed with cystectomy?

Answer 8

40-70% (depends on ureteral locations).

Question 9

Why is it important to keep trigone of the bladder intact when performing cystectomy?

Answer 9

Leaving the trigone intact is important for regeneration of bladder mucosa because the cells arise from epithelium of the terminal ureters and urethra (in the trigone).

Question 10

uroabdomen is a complication from cystotomy in what % of cases?

Answer 10

1.5%

Question 11

What layer of the bladder wall is the strength-holding layer?

Answer 11

Submucosal

Question 12

What is the best suture to use in the bladder?

What size and needle type?

Answer 12

Absorbable monofilament - less drag and bacterial adherence.

A study evaluating the tensile strengths of four monofilament suture materials found that while PDS and polyglyconate (maxon) are OK, poliglecaprone 25 (monocryl) may not have sufficient tensile strength during the critical phase of bladder healing in E. coli urine.

Question 13

Voluntary control of micturition occurs via what pathway?

Answer 13

Pudendal nerve control of striated urethral muscle and direct cortical innervation of the pontine micturition center.

Question 14

How is micturition stimulated?

Answer 14

When the bladder nears capacity, the distention of detrusor mm. activates stretch receptors -> parasympathetic stimulation -> reflex contraction of detrusor. Stretch receptors also lead to depression of sympathetic outflow and acts on the brainstem (pontine center) to cause relaxation of smooth/striated urethral muscles.
* integration of the brainstem is needed to sustain detrusor contraction long enough to void.

Question 15

Parasympathetic = pee
What are three “P”s involved?

Answer 15

Pelvic nerve (S1-S3)
Pudendal nerve (S1-S3)
Pontine micturition center (Pons, brainstem)

Question 16

Sympathetic = store
What is the non-s nerve (and it’s A and B receptors) that helps store urine?

Answer 16

Hypogastric nerve (TL spine)
Keeps smooth muscle tight with alpha receptors
Relaxes the detrusor with Beta receptors

Question 17

What lymphatics drain the bladder?

Answer 17

hypogastric and sublumbar LN

Question 18

What are the three parts of the bladder?

Answer 18

Apex
Body
Neck

Question 19

What suture materials are most appropriate for use in the bladder?
What organism disintegrated all tested sutures by day 7?

Answer 19

• Polydioxanone and polyglyconate
• Proteus mirabilis

Question 20

The ventral medial ligament connects the bladder to the linea and pubic symphysis. In fetuses, what else runs through here?

Answer 20

Urachus

Question 21

What are the layers of the bladder wall?

Answer 21

Urothelium (mucosa (transitional cells) and submucosa connective tissue)
Detrusor muscle (smooth, with oblique, interdigitating fibers)
Serosa

Question 22

Is there an anatomically distinct internal urethral sphincter?

Answer 22

NO
Urethral muscle is continuous with the detrusor.

Question 23

Where does all bladder innervation merge before entering the bladder at the neck?

Answer 23

The pelvic plexus

Question 24

What effect does azotemia have on anesthesia and surgery?

Answer 24

Alterations of pharmacokinetics of drugs and of animal’s sensitivity to those drugs.

Interferes with platelet function (check BMBT)

Question 25

What are the effects of hyperkalemia on anesthesia?

Answer 25

Bradycardia
Arrhythmias
Potentiates the cardio-depressant effects of anesthetic drugs. ** Correct it before surgery**

Question 26

How do you correct hyperkalemia in a urinary patient?

Answer 26

Fluid therapy, decompressive cysto or urinary diversion, peritoneal drainage, calcium gluconate, insulin+glucose, bicarbonate administration

Question 27

What antibiotics are a reasonable choice for perioperative antibiosis in bladder surgery?

Answer 27

Clavamox
3rd generation cephalosporins
(Broad-spectrum, bactericidal, non-nephrotoxic)
Give at induction then q2hr intraop, don’t continue unless infected (will not affect any cultures taken)

Question 28

What are good choices for oral empiric antibiotics in bladder procedures while culture is pending?

Answer 28

Clavamox, 3rd gen cephalosporins, enrofloxacin

Question 29

Suture-associated recurrent urolithiasis was reported in one study in what % of cases?

Answer 29

9.4% dogs, 4% cats but was retrospective, materials used were not reported.

In general, avoid nonabsorbables and try to avoid penetrating mucosa.

Question 30

What are principles of surgery for the bladder?

Answer 30

Gentle handling: stay sutures, moistened swabs, suction instead of swabs, keep everything moist, avoid cautery.

You may need an abdominal retractor - Tobias says the Gosset.

Question 31

What is different between a Balfour and Gosset retractor?

Answer 31

The Gosset retractor functions similarly to the Balfour retractor, but it is generally smaller and does not have a central blade)

Question 32

When should you use NSAIDs in a urinary surgery case?

Answer 32

Withold until normovolemic and eating / of course don’t use in renal failure.

Question 33

What is normal urine output in small animals?

Answer 33

1-2 mL/kg/hour