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

Question 34

What ligament connects the bladder apex to the linea alba and pelvic symphysis, and what embryologic structure does it contain in fetuses?

Answer 34

The ventral median ligament; it contains the urachus in fetuses.

Question 35

What structures are contained within the lateral ligaments of the bladder, and why are they surgically important?

Answer 35

They contain fat, the distal ureter, and umbilical artery remnants; they must be preserved to avoid ureteral injury.

Question 36

How does bladder position change with filling in dogs compared with cats?

Answer 36

In dogs it may lie in the pelvic canal when empty and extend cranially when distended; in cats it typically remains in the caudal abdomen even when empty.

Question 37

What are the three gross anatomic regions of the urinary bladder?

Answer 37

Apex, body, and neck.

Question 38

What is the trigone of the bladder and what structures define its boundaries?

Answer 38

The trigone is the internal triangular region defined by the two ureteral openings dorsally and the proximal urethral opening caudally.

Question 39

What epithelial type lines the urinary bladder and what functional property does it confer?

Answer 39

Transitional epithelium (urothelium), which allows distension while maintaining a barrier to urine.

Question 40

What is the strength-holding layer of the bladder wall that must be included during cystotomy closure?

Answer 40

The submucosal connective tissue layer.

Question 41

What is the detrusor muscle and how are its fibers organized?

Answer 41

The detrusor is the smooth muscle layer of the bladder wall composed of oblique, interdigitating fibers continuous with urethral smooth muscle.

Question 42

Why is there no anatomically distinct internal urethral sphincter in dogs and cats?

Answer 42

Because the detrusor muscle fibers are continuous with urethral smooth muscle at the vesicourethral junction.

Question 43

What is the outermost layer of the bladder wall?

Answer 43

The serosa.

Question 44

Which nerve provides sympathetic control of bladder storage and what are its two primary effects?

Answer 44

The hypogastric nerve; it contracts the bladder neck (alpha receptors) and relaxes the detrusor muscle (beta receptors).

Question 45

Which nerve mediates parasympathetic stimulation of detrusor contraction and urination?

Answer 45

The pelvic nerve.

Question 46

From which spinal cord segments does the pelvic nerve originate?

Answer 46

Sacral spinal cord segments S1–S3.

Question 47

Which nerve provides somatic innervation to the external urethral sphincter?

Answer 47

The pudendal nerve.

Question 48

What is the function of stretch receptors in the bladder wall?

Answer 48

They detect distension and initiate parasympathetic reflexes leading to detrusor contraction and urination.

Question 49

Where does integration of the detrusor reflex occur for coordinated urination?

Answer 49

In the pontine micturition center in the brainstem.

Question 50

What is excitation–contraction coupling in the detrusor muscle and why is it clinically important?

Answer 50

It is signal transmission between adjacent muscle cells; disruption leads to detrusor atony and urine retention.

Question 51

What is the primary arterial supply to the urinary bladder?

Answer 51

The caudal vesical artery.

Question 52

From which artery does the caudal vesical artery arise?

Answer 52

From the vaginal artery in females or prostatic artery in males, both branches of the internal pudendal artery.

Question 53

What vessel supplies the cranial bladder when patent?

Answer 53

The cranial vesical artery, a remnant of the umbilical artery.

Question 54

Where does venous drainage of the bladder occur?

Answer 54

Into the internal pudendal veins.

Question 55

To which lymph nodes does the urinary bladder primarily drain?

Answer 55

Hypogastric and sublumbar lymph nodes.

Question 56

How quickly does bladder mucosa heal after cystotomy?

Answer 56

Within approximately 5 days.

Question 57

When does full-thickness bladder healing regain near-normal tensile strength?

Answer 57

Within approximately 14–21 days.

Question 58

Why are absorbable monofilament sutures preferred for bladder closure?

Answer 58

They cause less tissue drag and bacterial adherence.

Question 59

Why should nonabsorbable sutures generally be avoided in bladder surgery?

Answer 59

They can predispose to cystic calculus formation.

Question 60

Which suture materials have superior tensile strength in bladder closure in infected urine compared with poliglecaprone?

Answer 60

Polydioxanone and polyglyconate.

Question 61

Why must the submucosa be included during bladder closure?

Answer 61

It is the primary strength-holding layer.

Question 62

What suture pattern is acceptable and not inferior to two-layer closure for cystotomy?

Answer 62

Single-layer, full-thickness appositional closure.

Question 63

What adjunct surgical technique can be used to augment bladder healing?

Answer 63

Omentalization or serosal patching.

Question 64

Why should electrocautery be avoided on the bladder wall during surgery?

Answer 64

It delays healing by causing tissue damage.

Question 65

What technique minimizes trauma when handling the bladder intraoperatively?

Answer 65

Use of stay sutures and moistened swabs.

Question 66

What is the normal urine output in dogs and cats during perioperative monitoring?

Answer 66

Approximately 1–2 mL/kg/hour.

Question 67

Why must hyperkalemia be corrected before anesthesia in urinary obstruction cases?

Answer 67

Because it can cause life-threatening arrhythmias and potentiate anesthetic cardiac depression.

Question 68

Why should NSAIDs be avoided in animals with renal failure or hypovolemia undergoing bladder surgery?

Answer 68

They can worsen renal perfusion and injury.

Question 69

Why is azotemia a major anesthetic concern in bladder surgery patients?

Answer 69

It alters drug metabolism and increases bleeding risk due to platelet dysfunction.