Surgery of the Kidney and Ureter Flashcards
What lies medial to the kidneys?
Aorta + vena cava
What lumbar vertebrae is the:
A) L kidney?
B) R kidney?
A) 1-3
B) 2-4
Where is the renal vein and artery found?
Renal hilus
Which kidney is more likely to have multiple arteries within?
Left
Is a Non obstructive calculi, especially if they are not associated with a pelvic dilation, an indication for nephrotomy?
no!
What are the indications for nephrotomy? (2)
Exploration of the renal pelvis (e.g. for masses or to identify causes/location of renal haematuria)
Retrieval of partially or completely obstructive calculi (renolith).
Why does a nephrotomy not effect renal function?
Minimal changes to GFR
How should nephrotomy be approached if a bilateral intervention is needed?
Staged proceedure
What 2 reasons would mean that a nephrotomy should not go ahead? (even if the patient meets the textbook criteria)
- If the renolith(s) is/are thought to be associated with recurrent urinary tract infection;
- If, in the presence of a renolith, renal function deteriorates despite adequate medical management - this is more common when renoliths are bilateral.
Which of the following is an indication for a nephrotomy?
A circumscribed renal sarcoma
An obstructive renolith
A localised renal infarct
An obstructive renolith
What needs to be occluded in a nephrotomy? How is this done?
Renal vessels;
- vasc clamps, tourniquet or finger pressure
What is the safe warm ischaemia time for renal vessels?
20 mins
What are the 2 access approaches to the renal pelvis?
Bisection approach
Intersegmental approach
What is the bisection approach?
The kidney is incised on its convex surface (bisection approach) and parenchyma is bluntly dissected towards the pelvis.
What is the intersegmental approach?
A scalpel handle is used to bluntly dissect the renal parenchyma, and the blood vessels are identified and ligated prior to transection. This reduces haemorrhage and parenchymal damage, though glomerular filtration rate studies have found no advantage over the bisection technique. This technique also takes longer than the bisection approach.
What instrument is used to explore the renal pelvis in bisectional approach?
Right angled forceps
How should the ureters be assess with bisectional nephrotomy?
By passing a urinary catheter and gently flushing the ureter normograde.
How is the kidney first layer closed?
Digital pressure is applied to appose the cut surfaces of the kidney for 1-5 minutes to allow a fibrin seal to form
How is the renal capsule closed
The renal capsule is apposed using a continuous and/or horizontal matters pattern.
What layer of the kidney should sutures NOT enter?
Deep into the cortex to avoid excessive tissue damage.
What suture pattern/s for closure of nephrotomy? (3)
- combination of mattress and simple continuous
- simple interrupted
-pledgeted sutures
What sutures are goo for friable nephrotomy?
pledgeted sutures (buttressed or supported by a small flat non-absorbent pad)
What could happen if the kidney has become detached in a nephrotomy? How can this be prevented
torsion around the vascular pedicle, it is advised to nephropexy (to body wall)
What is a pyelolithotomy?
alternative to the nephrotomy for treatment of obstructions located in the proximal ureter/renal pelvis if the proximal ureter and renal pelvis are significantly dilated, and avoids the parenchymal damage associated with nephrotomy.
What is the main risk of pyelolithotomy?
High risk of post op leakage at surgical site
What are recognised complications associated with nephrotomy?
- Haemorrhage
- Prolonged renal ischaemia
- Renal damage from manipulation
- Negative effect on renal function
How can prolonged renal ischaemia be reduced in surgery? (2)
- Mannitol
- Hypothermia
What are the indications for complete nephrectomy? (6)
- Renal neoplasia
- Irreparable trauma
- Pyelonephiritis resistant to medical therapy
- Essential/idiopathic renal haematuria (if sclerotherapy is not available)
- Vascular avulsion (surprisingly traumatic vascular avulsion does not usually result in fatal bleeding)
- Hydronephrosis complicated with infection, abdominal pain or ureteral malformations beyond repair.
Why use the term ureteronephrectomy?
Complete nephrectomy is more correctly termed ureteronephrectomy as the ureter is also removed in most cases.
If performing a nephrectomy, what is ideally performed on the other kidney?
Assessing function - glomerular filtration rate through administration of an exogenous marker or by nuclear scintigraphy
Why must the ureter by removed?
Predisposition to UTI
Where is ureter removed in ureteronephrectomy?
The level of the uretero-vesicular junction
Which cat breed get polycystic kidneys? (2)
Persian
British shorthair
What are renal cysts?
Epithelium-lined cavities filled with fluid of various composition
What are Calyceal diverticulum filled with?
urine
How common are Calyceal diverticulum?
Not described in vet med
What is a Calyceal diverticulum?
Cystic cavity within the kidney lined by transitional epithelium that communicates with a calyx or less commonly with the renal pelvis through a narrow isthmus
When is surgery indicated for a renal cyst? (3)
- Growth
- Infection
- Associated with clinical signs/Dx
What are renal cyst treatment options? (3)
- Percutaenous drainage
- Sclerotherapy
- Surgery
What are the surgical options for renal cysts? (3)
- Omentalisation
- Sclerotherapy
- ureteronephrectomy
When is ureteronephrectomy indicated for a renal cyst?
When the cyst has outgrown renal parenchyma
Renal tumours in dogs (4)
- Renal tubular carcinoma
- Sarcoma
- Lymphoma
- Nephoblastoma
Nephroblastoma signalment in dogs?
young-middle age
male
Renal Neoplasia in cats?
Lymphoma
Diagnosis of renal lymphoma in cats?
FNA
Where are adrenal tumours likely to spread?
Ipsilateral kidney
Surgical approach for nephrectomy?
Ventral incision - large! to examine for mets
How to visualise L + R kidney?
Colonic + duodenal manoeuvre
How to detach kidney from peritoneal attachments?
Sharp + blunt dissection and rotate/reflect
Seperate peritoneal fat
Where is the renal artery in relation to kidney?
Dorsal
Where is the renal vein in relation to kidney?
ventral
How are vessels ligated:
A) in neutered?
B) In entire?
A) Close to aorta + VC attachments
B) Distal to gonadal vein opening of renal vein
What suture for renal vasculature ligation
Polydioxanone (PDS)
Polyglyconate (Maxon),
Non-absorbable suture such as nylon or polypropylene.
How many sutures should be placed on vessel of renal vasculature staying in animal?
x2 or a vascular clip + ligature
Where is the ureter ligated and dissected?
Just external to bladder
What are recognised complications associated with nephrectomy?
- Haemorrhage (from main renal vessels)
- Contralateral ureteral damage (if kidney is large and deviated medially)
- Damage to aortic or caudal vena cava wall
- Urine leakage (at bladder site if trauma)
- Urine pooling (if ureter is left in place)
- Acute renal failure
Why should the ureter not be left attached to the bladder?
Lead to UTI
The most common primary renal tumour in dogs is:
Renal tubular carcinoma
Renal function of the remaining kidney should be assessed prior to surgery by measuring which parameter?
GFR
When performing a nephrectomy, the kidney should be reflected A) to allow access to the renal artery which lies B) to the renal vein.
A) Ventro-medially
B) Dorsal
Indications for partial nephrectomy (3)
- Well circumscribed renal mass (including abscess)
- Local infarct
- Resect/repair following renal damage
What sutures provide greatest resistance to urine leakage/haemorrhage?
Horizontal mattress
How is a partial neprectomy approached?
Like a total
- Occlude vascular pedicle; Rummel tourniquet or vascular clamp (Satinsky)
- Renal capsule peeled back and expose parenchyma
- Horizontal mattress sutures are then pre-placed in an overlapping fashion, proximal to the portion to be removed
- Sutures tightened
- Area resected and sutures tied
- Capsule reapposed over resected parenchyma
What are recognised complications associated with partial nephrectomy? (5)
- Ischaemic lesion of the remaining part of the kidney
- Haemorrhage
- Urine leakage
- Further trauma to renal parenchyma
- Suture slippage
When are renal biopsies indicated? (4)
investigate:
- haematuria or proteinuria or Acute renal failure
- When promary renal dx suspected
What are the contraindications for renal biopsies? (6)
- Coagulopahty
- Hypertension
- Pyelonephritis
- Renal cysts
- Renal abscess
- Hydronephrosis
What biopsy tends to be advised?
Tru-Cut biopsies of the renal cortex/masses are most appropriate in the vast majority of circumstances
Why should medulla be avoided in renal biopsies?
Risk of puncture of blood vessles
What needle gauge for renal biopsy?
16g/18g
How to close if a wedge biopsy is performed?
For closure, wide simple interrupted sutures using 3-0 or 4-0 monofilament absorbable material are placed across the defect including the capsule and parenchyma.
What are recognised complications associated with renal biopsies?
- Haemorrhage
- Effraction of the urinary collecting system
- Tearing of the capsule
