Introduction
- Three methods of gaining access to the kidneys:
- Percutaneous blind transabdominal approach (only useful in a limited number of cases in dogs) - suitable for needle biopsy with ultrasound control.
- Retroperitoneal (keyhole) dissection via sublumbar region possible in small thin dogs.
- Surgery - ventral midline laparotomy (for most major renal surgery).
Uses
Biopsy- Investigation of:
-
- Hematuria.
- Proteinuria.
- Renal insufficiency.
- Abnormal renal size/shape.
- Evaluation of renal disease, eg severity, reversibility, progression.
- Evaluation of response to therapy.
Renal surgery
- Ureteronephrectomy
. - Nephrolithotomy .
- Pyelithotomy .
- Nephrostomy tube placement.
Advantages
Midline- Good access to either kidney.
- Visualization of focal lesions to assist sampling representative area.
- Access to vascular supply.
- Can mobilize and stabilize whole kidney.
- May be possible to perform without general anesthesia.
- Less invasive.
Disadvantages
Retroperitoneal- Difficult to expose entire kidney particularly on right side.
- Difficult to fix kidney.
- No access to renal pelvis.
- Unfamiliar approach to many surgeons.
- Not feasible in very obese animals.
- Requires full theatre facilities and general anesthesia.
- Requires full theatre facilities and general anesthesia.
- Must be able to identify and fix kidney before biopsy.
- Cannot sample focal lesions without ultrasound guidance.
- Less able to control and reassess situation, ie hemorrhage more likely.
Requirements
Materials required
Minimum equipment
- Laparotomy set for midline and retroperitoneal approach.
- Suture pack and core biopsy needle for percutaneous technique.
- Vascular occlusion equipment, eg Rummel tourniquet or vascular clamp.
Ideal equipment
- Ultrasound guidance.
Ideal consumables
- Automatic core biopsy needle.
Sequelae
Reasons for treatment failure
- Non-representative biopsy if focal lesion missed in biopsy or if sample too small (usually complications of techniques with poor visibility).
