Kidney and Ureters (E1) Flashcards
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
2nd: Struvite
What clinical signs are associated with nephroliths?
Can be absent or non specific
Depression
Anorexia
Hematuria
Pain
(Uremia, Hydronephrosis)
How are nephroliths diagnosed?
Survey rads
Ultrasound
What parameters are used to determine the best management for nephroliths?
Type of calculi
Anatomical location
Clinical effects
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?
- Blind percutaneous
2. Percutaneous, US guided (PREFERRED)
- Laproscopic
- Keyhole abdominal incision
- 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?
Retroperitoneal fat
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)
Satinsky clamp
20 minutes
When performing a nephrolithotomy, what type of incision do you make to open the kidney? How do you close the surgical site?
Sagittal
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:
- Monitor renal function/renal imaging
(+) No iatrogenic damage from meds or sx
(-) Disease may progress
- Medical mgmt
(+) No damage from surgery, no anesthesia
(-) Medication side effects, may eventually need sx anyway
If symptomatic:
- Surgery to remove stones
(+) Definitively removes the stone(s)
(-) Surgery causes nephron/kidney damage
- Lithotripsy
(+) 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?
Longitudinal
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
US
Exploratory sx
(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?
Severe infection
Severe trauma
Obstructive calculi w/persistent hydronephrosis
Neoplasia
Transplant
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?
Separately
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?
Nephroblastoma
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?
Suspected neoplasia
Nephrotic syndrome
Renal cortex disease
Non-diagnosed ARF
(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?
Irreversible ARF
Decompensated CRF
PKD
C/O’s: viral positive (FeLV, FIV), cardiac disease, neoplasia, fractious
What screening parameters are used to assess feline renal transplant candidates? What are some special considerations that must be made/owners must be made aware of? What is the prognosis post-transplant?
Screening: CBC/chem, U/A and culture, abdominal rads, US, Echo, test for FeLV, FIV, and Toxo
Considerations: Very expensive, many vet visits, lifelong immunosupression, owner must adopt donor cat too
Prognosis: 613 days (23% do not survive to discharge)
#1 complication is acute rejection
Which breeds are predisposed to ectopic ureter? Is it more common in males or females? Young or old?
Siberian
Huskies
Labrador/Golden Retrievers
WHWTs
Females
Young
What clinical signs are associated with ectopic ureter?
Incontinence (most common)
Failure to house-break
UTIs
Urine scalding
What are the classifications of ectopic ureter and what do they mean? Which is more common?
Extramural: Enters and exists in the wrong place; Ureter bypasses the bladder to enter urethral lumen; enters into neck, urethra, or vagina
Intramural: Enters normally but exits abnormally, it extends submucosally within the bladder wall before entering the uretheral lumen
Intramural is most common in dogs (Bilateral ectopic ureters are also common)
How do you diagnose and classify ectopic ureter?
Excretory urography
+/- Fluoroscopy
(Can do Pneumocystography first)
Cystoscopy (most reliable, sensitive and specific)
How do you treat extramural ectopic ureters? Intramural? What is the prognosis post-treatment?
Surgery- Neouretercystostomy (Extra and Intramural)
Cystoscopic Laser treatment (INTRAmural)
Prognosis: 60% incontinence improves, 90% improvement when add meds (PPA); other functional abnormalities may still exist (remember, congenital anomalies usually don’t show up alone)
What is an ureterocele? What are the 2 types of ureteroceles? What are the clinical signs?
Definition: Dilation (‘Ballooning’) of the distal ureter where it opens into the bladder, due to a persistent embryonic membrane
Intravesicular
Ectopic
CS: UTI, incontinence, azotemia if obstructed
How are ureteroceles diagnosed and what specifically are you looking for? How are they treated?
IV urography to look for the “Cobra head sign”, US
Intravesicular: Ureterocelectomy (removal of ureterocele)
Ectopic: Neoureterocystostomy with ureterocelectomy (remove ureterocele and re-transplant ureter to normal position)
What are the causes of ureteral trauma? How is it diagnosed?
Main cause is IATROGENIC
Also blunt trauma and obstruction
Dx: Presence of uroretroperitoneum/ uroabdomen, Rads, IV UROGRAPHY (localizes lesion)
What are the criteria fro treating ureteral trauma? What are the treatment options (include advantages and disadvantages of each)?
Time, location, severity
If have normal contralateral function, can remove the entire affected kidney and ureter (cheaper, easier sx, but not ideal because removing the kidney)
Nephroureterectomy
(+) Minimizes complications
(-) Expensive
Ureteroureterostomy/ ureteral anastomosis (procedure of choice for proximal ureter)
(+) Only option for proximal ureter because cannot reimplant
(-) Special requirements (magnification), very difficult, complications common (strictures, dehiscence)
Neoureterocystotomy / ureteral reimplantation
(+) Good for cats
What are the 2 methods are available for urinary diversion after ureteral surgery?
Ureteral stent
Nephrostomy tube
What procedures can be used if you have loss of length of the distal or proximal ureter?
Renal descensus (suture kidney to lumbar musculature)
Nephrocystopexy (suture kidney to cranial edge of bladder)
Psoas hitch (suture bladder craniodorsally to psoas minor)
Transureteroureterostomy (connects ureters to each other across midline)
For DISTAL ureter: Bladder wall flap
What are the clinical signs of ureterolithiasis? How is it diagnosed?
CS: Asymptomatic UTI, hematuria, anorexia, lethargy, pain (primarily occurs in CATS)
Dx: Rads (most are CaOx), US (also see dilation of ureter/pelvis)
What are the non-surgical treatment options for ureterolithiasis? What are the indications for surgery?
Tx’s: IVF Diuretics Smooth muscle relaxers (Prazosin)
Sx indications: Completely obstructed, Azotemia, Pyelonephrotis, 2 weeks of unsuccessful medical treatment
What surgical procedures are done for ureterolithiasis?
Cystotomy and retrograde flushing followed by removal via Pyelithotomy
Ureterotomy followed by Nephrostomy drainage
What are the indications for permanent ureteral stenting?What are the advantages and disadvantages?
Indications: Stone, Tumor, Stricture, Blood clot
(+) Decreased morbidity, shorter hospitalization, less complications
(-) Specialized equipment, steep learning curve
