What is the arterial supply of the kidney? Venous?
Renal artery (arises form aorta between cranial and caudal mesenteric A's) then BRANCHES into dorsal and ventral at hilus (sometimes more than 1 renal A on left side)
Renal vein (empty into caudal vena cava)
What are the most common nephroliths?
Most common: Calcium oxalate
What clinical signs are associated with nephroliths?
Can be absent or non specific
How are nephroliths diagnosed?
What parameters are used to determine the best management for nephroliths?
Type of calculi
When is surgery for nephroliths indicated? What is indicated before surgery (tests/examinations)?
Sx indicated if OBSTRUCTED or INFECTION (pyelonephritis) associated with the calculi is present
Prior to surgery: Check renal function - excretory urography, GFR, Ultrasound
A ______ is the excision of the kidney. A ________ is a surgical incision into the kidney. A _______ is th creation of a permanent fistula leading to the renal pelvis.
NephrECTOMY - Excision
NephrOTOMY - incision (cuT)
NephroSTOMY - fiSTula
What techniques can be used to perform a renal biopsy?
1. Blind percutaneous
2. Percutaneous, US guided (PREFERRED)
4. Keyhole abdominal incision
5. Wedge or incisional (via ventral midline ceiliotomy) (most diagnostic, requires vessel occlusion)
(Best if using spring-loaded biopsy needle (Monopty biopsy needle) or biopsy gun, manual devices (e.g. Tru-Cut) not as good b/c can produce fragmented samples)
What type of incision do you make to perform a nephrolithotomy? What organs must you retract to visualize the kidneys?
Ventral midline celiotomy
Mesocolon (left) or mesoduodenum (right)
To isolate the renal vessels, what will you need to dissect?
When performing a nephrolithotomy, what instruments can you use to occlude the renal vessels? How long can they remain occluded?
Rumel Tourniquet (red rubber catheter, umbilical tape and hemostat)
Bulldog vascular clamps (very atraumatic if placed gently)
When performing a nephrolithotomy, what type of incision do you make to open the kidney? How do you close the surgical site?
Suture-less closure (hold for 5 minutes, then suture only the capsule) or
Horizontal mattress (Use absorbable suture like PDS or Vicryl)
When performing a nephrolithotomy, after removing the stone, what do you do next (3 things)?
Culture the renal pelvis
Flush the pelvis/ureter with heparinized saline
Catheterize the ureter to ensure patency
What are the advantages of pyelolithotomy over a nephrolithotomy? When is a pyelolithotomy indicated?
Does not require occulusion of the blood supply
Does not damage nephrons
Indicated when the calculi are in the renal pelvis and the pelvis and the proximal ureter(s) are dilated
What are the what are the treatment options for nephroliths (2 options for asymptomatic, 2 options for symptomatic)? Give advantages and disadvantages for each.
If the patient is asymptomatic:
1. Monitor renal function/renal imaging
(+) No iatrogenic damage from meds or sx
(-) Disease may progress
2. Medical mgmt
(+) No damage from surgery, no anesthesia
(-) Medication side effects, may eventually need sx anyway
3. Surgery to remove stones
(+) Definitively removes the stone(s)
(-) Surgery causes nephron/kidney damage
(+) Shock waves break up stone(s) into pieces small enough to void, so avoid surgery
(-) Pieces may get stuck in and damage or occlude ureters/urethra, can damage kidney, not readily available
What type of incision do you make in the kidney for a pyelolithotomy?
What is the post-op management of a nephrolithotomy (what procedures, tests and treatments)?
Post-op rads (for calculi)
Monitor: PCV, CVP (hydration), urine output, renal enzymes and e-lytes
Provide diuresis (to maintain perfusion and minimize clot formation)
How can you diagnose renal trauma (3 ways)?
Contrast excretory urography
(Clinically, may have hematuria)
How would you treat/manage minor renal trauma? What is considered moderate trauma and how would you treat/manage it? What about major trauma?
Minor: Conservative treatment
Moderate: Capsular tears, extravasated fluid
Tx- Repair w/Sx, use hemostatic agents, Omental patching
Major: Severe parenchymal or vascular damage
Tx- Repair with Partial nephrectomy or Nephroureterectomy
What are the indication for performing a nephroureterectomy?
Obstructive calculi w/persistent hydronephrosis
Although it is infrequently performed, when would you chose a partial nephrectomy? What are the advantages and disadvantaged vs a nephroureterectomy?
If the other kidney is compromised (decreased GFR), trauma or neoplasia is focal
(+) Preserves renal function
(-) Technically more difficult, higher incidence of post-op hemorrhage
In a partial nephrectomy, do you ligate the vessels together or separately? Where do you separate and ligate the ureter?
At vesicoureteral junction
What are the clinical signs associated with hydronephrosis, uni and bilateral? How is it diagnosed? How is it managed? What is the prognosis if the obstruction is <1 week? >4 weeks?
CS (unilateral): abdominal distention, palpable mass
CS (bilateral): severe azotemia, death
Dx: Abdominal rads, Excretory urogram, US
Mgmt: Eliminate cause, evaluate function; if non-functional or severely damaged parenchyma then SX- Nephroureterectomy
Prognosis <1week: complete resolution
>4weeks: MAY regain 25%
What are the clinical signs associated with pyelonephrosis? What are possible causes? How is it diagnosed? How is it managed?
CS: PUPD, lethargy, depression, fever, and anorexia
Causes: Complication of obstructive uropathy, ascending infection, hematogenous, post-parenchymal damage (can predispose)
Dx: US and IV pyelography
Mgmt: Nephrouretectomy if advanced
What are the clinical signs associated with the giant kidney worm (Dictophyma renale)? How is it diagnosed? How is it managed?
CS: Can be asymptomatic, or same as renal failure (due to worm causing parenchymal damage), vomiting when L3 penetrate stomach
Dx: Often on necropsy, exploratory sx, possibly see eggs in urine (urine sedimentation)
Mgmt: Nehrouretectomy, Nephrotomy
(Fun fact, usually affects RIGHT kidney or found in peritoneal cavity)
What is the most common benign kidney tumor in dogs and cats? Most common malignant kidney tumor? How are these tumors managed?
Benign: Renal adenoma
Malignant (more common): Renal cell carcinoma (dogs), Renal lymphoma (cats)
RCC: (Unilateral) nephrouretectomy and chemo, Exploratory laparotomy for metastatic lesions and biopsy (best method for biopsy)
Lymphoma: Usually not Sx unless tumor itself is causing an issue (e.g. obstruction), chemo
What do you call rapidly developing, malignant mixed tumors that arise from embryonal elements of the kidney? What is the typical signalment? How is it managed?
Young dogs and cats
Mgmt- if unilateral Nephrouretectomy, if bilateral could consider Partial nephrectomy (Nephron sparing sx); Chemo can be attempted
(Note: Metastasis VERY common, MST= 6 mo)
What are the clinical signs of renal neoplasia? How is it diagnosed?
CS (depend on type, size and location): hematuria (most common), abdominal distention, anorexia, weight loss, depression, abdominal pain
Dx -Best = IV Urography; abdominal palpation, abdominlal rads, US, CT, MRI
What parameters are used to determine if a renal biopsy is indicated? What are contraindications? What are the risks of performing this procedure?
Renal cortex disease
(Only perform if benefits outway risks)
C/O's: coagulopathy (can cause fatal hemorrhage), hypertension, severe chronic hydronephrosis
Risks: Hemorrhage, Blood clot formation (can cause ureteral obstruction which can cause hydronephrosis)
What are indications for a feline renal transplant? Contraindications?
C/O's: viral positive (FeLV, FIV), cardiac disease, neoplasia, fractious