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Small animal surgery I > Surgery of the kidney > Flashcards

Flashcards in Surgery of the kidney Deck (58)
1

What is the arterial and venous blood supply of the kidney?

Renal artery and vein (at renal hilus)

2

What are the most common nephroliths?

Ca oxalate

3

What clinical signs are associated with nephroliths?

  • Absent or nonexistent
  • Depression, anorexia, hematuria, pain

4

How do you diagnose nephroliths?

Radiographs (Ca oxalate radiopaque)

Ultrasound

5

What parameters do you use to determine the best management for nephroliths?

  • Type of calculi
  • Anatomical location
  • Clinical effects

6

When is surgery for nephroliths indicated?

Obstruction

Infection associated with calculi (i.e. pyelonephritis)

7

What are the treatment options for nephroliths?

Medical management

Nephrolithotomy

Pyelolithotomy

8

What are the advantages/disadvantages of medical management of nethroliths?

  • Advantage--less invasive
  • Disadvantages
    • Risk of obstruction elsewhere if stones are not broken down small enough
    • Can exacerbate stone's effects if treat for wrong stone type

9

What are the advantages/disadvantages of nephrolithotomy?

  • Advantages
    • Relatively simple procedure
    • Can close via sutureless closure
  • Disadvantages
    • Clamp time is only 20 minutes--if clamp longer can cause permanent vasculature damage
    • Risk of renal torsion if kidney is not reattached high enough

10

What are the advantages/disadvantages of pyelolithotomy?

  • Advantages
    • Doesn't require occlusion of blood supply
    • Doesn't damage nephrons
  • Disadvantages
    • Area only seen when both renal pelvis and proximal ureter are dilated

11

How do you perform a nephrolithotomy?

  • Retract mesocolon/mesoduodenum (to prevent excessive hemorrhage)
  • Dissect retroperitoneal fat (to isolate vessels--must ID renal vessels and ureter to avoid damage)
  • Temporarily occlude blood supply to kidney
  • Mobilize kidney, then make sagittal incision until you reach level of renal stone 
  • Remove stone manually (save to submit for qualitative analysis and culture the renal pelvis--often assoc. w/ infection)
  • Flush renal pelvis and ureter with sterilized heparin saline (to wash away any clots)
  • Catheterize ureter to ensure patency
  • Close

12

What instruments can you use to occlude the renal vessels for a nephrolithotomy?

  • Rumel tourniquet
    • Umbilical tape + hemostat
  • Bulldog vascular clamp
    • Non-traumatic jaws
  • Sitiske clamp
    • Curved, non-traumatic occlusion

13

How long can you occlude renal vessels during surgery?

Max of 20 minutes!

14

What are the closure methods following a nephrolithotomy?

  • Sutureless closure
    • Most common
    • Hold kidney closed for 5 minutes
    • Fibrin seal forms
    • Suture capsule only (continuous pattern)
  • Horizontal mattress (renal cortex)
  • Reattach kidney back to where it was to avoid renal torsion

15

When is a pyelolithotomy indicated?

When proximal ureter and renal pelvis are dilated due to obstruction (when stone is located further down in pelvis area)

16

What are the advantages of a pyelolithotomy over a nephrolithotomy?

  • Prevents destruction of renal tissue--incision is made directly over stone in the renal pelvis
  • Does not require occlusion of blood supply

17

What is the post-operative management of nephrolithotomy?

  • Post-op rads to look for calculi
  • Monitor PCV
  • CVP (hydration)
  • Monitor urine output
  • Monitor renal enzymes/electrolytes
  • Provide diuresis
    • Maintains renal perfusion and minimizes clot formation

18

How can you diagnose renal trauma? 

  • Diagnosis
    • Contrast excretory urography
    • Exploratory celiotomy
    • Ultrasound

19

T/F: Hematuria is an indication for renal surgery

FALSE--it is not an indication for surgery

20

What is the treatment for minor renal trauma?

Conservative treatment

(bruising, subscapular hematoma)

21

What is the treatment for moderate renal trauma? What are some examples of moderate trauma?

Surgical intervention

Hemostatic agents/partial nephrectomy

Omental patching

Ex: Capsular/parenchymal tears, extravasated urine/blood

 

22

What define major renal trauma? 

What is the treatment for it?

What should you ALWAYS do first?

  • Extensive parenchymal or vascular damage can lead to hemorrhagic shock and death
  • If parenchyma is shattered consider partial nephrectomy or nephroureterectomy
  • Evaluate contralateral kidney first

23

What are the indications for performing a nephroureterectomy?

  • Severe infection
  • Severe trauma
  • Massive hemorrhage, severe tearing of renal tissue
  • Obstructive calculi with persistent hydronephrosis
  • Neoplasia
  • Transplant (felines)

24

What are the indications for a partial nephrectomy?

  • Only indicated if patient has severe contralateral renal damage
    • Compromised GFR in other kidney
    • Trauma/focal hemorrhage/neoplasia

25

What are the disadvantages of performing a partial nephrectomy?

Higher incidence of post-op hemorrhage

Technically more difficult

26

What are the clinical signs of hydronephrosis?

  • Unilateral
    • Abdominal distension
    • Palpable mass
      • Mass will be large and regular (neoplasia = irregular)
  • Bilateral
    • Severe azotemia
    • Death

27

How do you diagnose hydronephrosis?

Abdominal rads

Excretory urogram

Ultrasound

28

How do you manage hydronephrosis? Will renal function return?

  • Eliminate cause
  • Evaluate function
  • < 1 week obstruction--> complete resolution
  • > 4 week obstruction--> might regain 25%
  • Nephroureterectomy
    • Non-functional or severe renal damage

29

What are the clinical signs of pyelonephritis?

Signs of infection 

Often associated with stones

30

What are the diagnostics of pyelonephritis?

Ascending infection; predisposed by damaged parenchyma

Can evaluate permanent renal damage with renal function tests

31

How do you manage pyelonephritis?

  • Often have to remove stone to rid of infection
  • Continue treatment with antibiotics after removal
  • Nephroureterectomy

32

Giant kidney worm: everythang 'bout it (basics)

  • Dioctophyma renale
  • Fish or frog consumption
  • Destroys renal parenchyma
  • Often diagnosed on necropsy
  • Nephrectomy or nephrotomy

33

What is the most common benign kidney tumor in the dog? In the cat?

Renal adenoma (both dogs and cats)

34

What is the most malignant kidney tumor in the dog? In the cat?

Dog = renal cell carcinoma

Cat = renal lymphoma

35

How do you manage renal cell carcinomas in dogs?

Nephroureterectomy + chemotherapy

MST = 6.8 mo

36

How do you manage renal lymphomas in cats?

Chemo therapeutics

(Not commonly a surgical disease unless causing significant obstruction in urinary tract)

37

What is a nephroblastoma? What kind of patient does it occur in?

Congenital neoplasia--part of the developing kidney

Occurs in younger patients

38

How do you manage a nephroblastoma?

Remove if possible (treatment of choice in humans is removal); if not, chemotherapy

MST = 6mo

39

What are the clinical signs of renal neoplasia?

  • Signs vary with type, location, and size
  • Hematuria
  • Abdominal distension
  • Anorexia
  • Weight loss
  • Depression
  • Abdominal pain

40

How do you diagnose renal neoplasia?

  • Abdominal palpation
  • Abdominal rads
    • 81% abdominal mass
    • 54% renal mass
  • Ultrasound
    • ​100% abdominal mass
    • ​85% kidney mass
  • IV urography, CT, MRI

41

What are the indications for a renal biopsy?

  • Suspected neoplasia
  • Nephrotic syndrome (PLN)
  • Renal cortex disease
  • Non-diagnosed ARF

42

What should you consider before performing a renal biopsy?

If the information gained will outweigh the risks

43

When should you avoid performing a renal biopsy?

  • Avoid if results don't:
    • Alter course of therapy
    • Change prognosis with diagnosis (CRF)
    • Owner won't pursue further therapy
    • Higher risk of serious complications

44

What are some complications of performing a renal biopsy?

  • Coagulopathies (clotting profiles)
  • Hypertension (risk of hemorrhage)
  • Severe chronic hydronephrosis (nephroureterectomy)

45

What sample size is needed for a renal biopsy? What is the common instrument used?

Sample size must be diagnostic (5-6 glomeruli)

Monopty biopsy needle (spring activated)

46

What are the various techniques for performing a renal biopsy?

  • Percutaneous
  • Ultrasound-guided (preferred method)
  • Keyhole
  • Laparoscopic-assisted
  • Wedge/incisional 

47

What is the percutaneous renal biopsy technique?

  • Small cats/dogs
  • Secure kidney against abdominal wall
  • Blind technique--doesn't visualize target lesions
    • Risk of hitting vessels

48

What is the ultrasound-guided renal biopsy technique?

  • Preferred method--non-invasive, no surgical approach
  • Very diagnostic
  • Advance needle into prepared area
  • Penetrate capsule
  • Can ID target lesions

49

What is the keyhole renal biopsy technique?

  • Modified surgical flank approach
  • Isolate kidney in flank area
  • Make keyhole incision-->dissect down to renal tissue with hemostats
  • Introduce biopsy needle

50

What is the laparoscopic renal biopsy technique?

  • Forceps hold kidney
  • Skin incision
  • Needle placement through incision (visualize with laparoscope) 

51

What is the wedge/incisional biopsy technique?

  • Ventral midline celiotomy
  • Occlude renal vessels
  • Crescent-shaped sample
  • 5-10mm long
  • 5mm deep in cortex
  • Close with mattress suture

52

What are the possible complications of a renal biopsy?

  • Severe hemorrhage
    • Hypertension
    • NSAID w/in 5 days
    • Coagulopathy
    • Poor technique
  • Hematuria (usually resolves in 2-3 days)
  • Hydronephrosis (ureteral obstruction from clot)

53

What are the indications for a feline renal transplant?

  • Irreversible ARF
  • Decompensated chronic renal failure
  • Polycystic disease

54

What are the special considerations of a feline renal transplant?

  • Cost
  • Frequent visits
  • Immunosuppression 

55

What are the screening parameters for a feline renal transplant?

  • CBC, chem profile
  • U/A and culture
  • Abdominal rads, u/s, echo
  • FELV, FIV, toxo

56

What 4 things will lead to rejection from a feline renal transplant consideration?

  • Virus positive
  • Cardiac disease
  • Neoplasia
  • Fractious

57

What is required of feline renal transplant donors?

  • Excellent health
  • 1-3 years old
  • Similar screening process for acceptors 
  • Blood type/cross match

58

What is the prognosis for feline renal transplant patients?

  • MST = 613 days
  • 23% do not survive discharge