1. Ultrasound Guided
Biopsies
Wendy Blount, DVM
Free PowerPoint Templates

2. Indications for US Guided Biopsy
Solid soft tissue masses visible by ultrasound
If mixed echo pattern, go for a solid spot
Take care aspirating fluid filled structures in body cavities
Aspirate the gall bladder only if you are prepared to do interventional surgery onsite
Aspirate GB only under sedation & with informed consent
Be prepared for interventional surgery for hypoechoic lesions in liver, spleen & other internal organs
Free PowerPoint Templates

3. Indications for US Guided Biopsy
FNA of fluid filled uterus is never recommended
Percutaneous draining of local peritonitis, pancreatic abscesses, perinephric cysts can be attempted
Septic contamination of the peritoneal cavity less likely with these
Scanners with needle guides and needle path screen guides are nice
Take 2-3 samples for better results
Free PowerPoint Templates

4. Indications for US Guided Biopsy
FNA of fluid filled uterus is never recommended
Percutaneous draining of local peritonitis, pancreatic abscesses, perinephric cysts can be attempted
Septic contamination of the peritoneal cavity less likely with these
Scanners with needle guides and needle path screen guides are nice
Free PowerPoint Templates

5. Indications for US Guided Biopsy
FNA of fluid filled uterus is never recommended
Percutaneous draining of local peritonitis, pancreatic abscesses, perinephric cysts can be attempted
Septic contamination of the peritoneal cavity less likely with these
Scanners with needle guides and needle path screen guides are nice
Free PowerPoint Templates

6. Patient & Equipment Preparation
Clip fur and do customary surgical prep
If you are going to touch the entry site with your fingers, don sterile gloves for FNA
Don sterile gloves for core biopsies, and place a sterile glove or probe cover over the probe
Use sterile surgical lube under the probe cover as well as on the patient
May or may not need sedation for FNA
Sedation required for core biopsy
Consider scheduling all FNA/biopsies in the AM
Free PowerPoint Templates

7. Triplett – Fisher Scientific
Patient & Equipment Preparation
Pre-Sampling Lab work
CBC confirming platelets >50,000/ul within 24 hrs
(Buccal Mucosal Bleeding Time (BMBT) <2 minutes
Triplett – Fisher Scientific
Jorvet - Surgicutt
Free PowerPoint Templates

8. Patient & Equipment Preparation
Pre-Sampling Lab work
CBC confirming platelets >50,000/ul within 24 hrs
(Buccal Mucosal Bleeding Time (BMBT) <2 minutes
Lift the upper lip (gauze muzzle)
Remove the device safety tab
Place the device on the mucosa
Push the device trigger button
Dab dripping blood every 15
seconds, but don’t touch the clot
6. BMBT = when bleeding stops
Free PowerPoint Templates

9. Patient & Equipment Preparation
Pre-Sampling Lab work
CBC confirming platelets >50,000/ul within 24 hrs
(Buccal Mucosal Bleeding Time (BMBT) <2 minutes
If liver disease, PT/PTT
Any preanesthetic lab work or other diagnostics indicated for safe anesthesia
Sterilize Needle Guide, if used
Some are disposable
Some gas sterilized, autoclaved or gluteraldehyde
Free PowerPoint Templates

10. Patient & Equipment Preparation
Supplies
FNA needles – 22-25g for internals, any size for peripherals
1-1/2 inch, 3 inch spinal needles
Sterile core biopsy needles 18g – 14g
Can re-autoclave until dull
Measure and label needle throw path
Glass slides, stains, decent cytology microscope
Formaldehyde cups for core biopsies
25g x 5/8” needles for teasing core biopsies out of needle
Free PowerPoint Templates

11. Tips for US Guided FNA/Biopsy
Choose the shortest direct path between skin and the target
Try not to pass through more than one body cavity, and not more than one organ
Separate needle for each location
Indirect guidance – use US to find a good place, and then do a blind needle pass
Draping usually not necessary
Stab incision needed for core biopsy, but not FNA
Free PowerPoint Templates

12. Free Hand vs. Needle Guide
Needle guides usually have a fixed angle of entry
If you miss, adjust the probe angle
With free hand, you can also adjust the needle angle
Superficial structures will probably have to be done free hand or with indirect guidance
Free PowerPoint Templates

13. FNA vs. Core Biopsy FNA probably better for vascular areas
Core biopsy for large solid lesions
Check your FNA cytology, and if non-diagnostic, consider a core
Sacrifice a core biopsy for cytology to make sure you have a good sample
Free PowerPoint Templates

14. FNA vs. Core Biopsy FNA probably better for vascular areas
Core biopsy for large solid lesions
Check your FNA cytology, and if non-diagnostic, consider a core
Sacrifice a core biopsy for cytology to make sure you have a good sample
Needle throw length
Free PowerPoint Templates

15. Tips for FNA Try a “core” FNA first with no attached syringe
Less hemodilution
Attach air filled 10cc
syringe and propel
needle contents onto
a slide
Prep, dry and stain as
usual
Free PowerPoint Templates

16. Tips for FNA Try a “core” FNA first with no attached syringe
Less hemodilution
If that fails, add aspiration with syringe
2cc saline in syringe for
better recovery on firm
lesions that produce scant
samples
Spin down & prep slides from
sediment
Free PowerPoint Templates

17. Tips for FNA Try a “core” FNA first with no attached syringe
Less hemodilution
If that fails, add aspiration with syringe
2cc saline in syringe for better recovery on firm samples that produce scant samples
Spin down & prep slides from sediment
If that fails try a larger needle if deemed safe
Or a needle with stylet (spinal needle), followed by aspiration
Free PowerPoint Templates

18. FNA/Biopsy of Liver
Difficult to impossible in deep chested dogs with small livers
Use the ultrasound to avoid pleural cavity when using intercostal approach
Liver biopsy/FNA for diffuse disease – left lobes
Use US to avoid GB and vessels
Penetrate through the capsule before deploying the Trucut to minimize bleeding
Free PowerPoint Templates

19. FNA/Biopsy of Liver Indirect Ultrasound Guidance
Notch between xyphoid and costal arch
Choose needle length sufficient to penetrate
falciform ligament (at least 1-1/2“)
Check for liver presence with the US probe
Clip & surgically prep the area
Penetrate the skin and pause
Pass needle to the hub into the liver
Direct needle 45o to table, toward head
Do not redirect – straight in, straight out
Core first, then add aspiration if needed X
Free PowerPoint Templates

20. FNA/Biopsy of Liver Indirect Ultrasound Guidance
Notch between xyphoid and costal arch
Choose needle length sufficient to penetrate
falciform ligament (at least 1-1/2“)
*Quickly* squirt needle contents onto a slide
Prep, dry and stain as usual
Confirm that you have hepatocytes on the slide
Big purple cells – granular cytoplasm
Free PowerPoint Templates

21. FNA/Biopsy of Spleen
Very low risk of bleeding for diffuse disease and solid tumors
Significant hemorrhage risk for cystic structures
Indirect ultrasound guidance often sufficient for diffuse disease
Free PowerPoint Templates

22. FNA/Biopsy of Kidneys
Can do blindly by palpating the kidney with one hand and aspirating or biopsying the
caudal pole with the other
Or ultrasound guided
freehand for diffuse disease
Penetrate renal capsule
Measure needle throw with calipers, to avoid renal artery, aorta and caudal vena cava
Deploy biopsy needle, remove biopsy needle, apply pressure
Harvest biopsy sample for histopathology and/or cytology
Free PowerPoint Templates

23. FNA/Biopsy of Prostate
If smallish masses cannot be accessed transabdominally, they can be accessed rectally using a Franzen needle for FNA
Free PowerPoint Templates

24. FNA/Biopsy of Prostate
If smallish masses cannot be accessed transabdominally, they can be accessed rectally using a Franzen needle for FNA
Free PowerPoint Templates

25. FNA of Bone Lesions I use an 18g needle, add aspiration if needed
Sedation or at least pain meds on board
normal bone cortex
metastatic bone lesion
Free PowerPoint Templates

26. FNA of Lung Lesions
Difficult to differentiate collapsed lung from mass
Lung more wedge shaped, with “hepatized” pattern
Linear probe best for this
Needle 19g or smaller - fewer complications
No FNA with needle only – maintain negative pressure to prevent pneumothorax
Extension set between needle & syringe (or butterfly)
Maintains negative pressure
Prevents trauma during aspiration
Free PowerPoint Templates

27. FNA of Lung Lesions
Difficult to differentiate collapsed lung from mass
Lung more wedge shaped, with “hepatized” pattern
Linear probe best for this
Needle 19g or smaller - fewer complications
No FNA with needle only – maintain negative pressure to prevent pneumothorax
Extension set between needle & syringe (or butterfly)
Maintains negative pressure
Prevents trauma during aspiration
Free PowerPoint Templates

28. Pitfalls of FNA & Biopsy
FNA/biopsy of adrenals and pancreas are often non-diagnostic
Most helpful when ruling out neoplasia
Adrenals are highly vascular and tend to bleed
Free PowerPoint Templates

29. FNA & Biopsy Complications
Bleeding – watch for this with the US probe for 5 minutes after last stick (<1% hemorrhage risk)
If bleeding is a concern, stick to a smaller needle
Use Doppler to identify and avoid large vessels
Small amount of self limiting bleeding is no problem (5%)
Asymptomatic pneumothorax after lung aspirate no problm
Rupture of fluid filled structure
Gall bladder – bile peritonitis
Abscess or gut – sepsis
Urinary tract - uroabdomen
Free PowerPoint Templates

30. FNA & Biopsy Complications
Seeding of neoplasia
Highest risk is with transitional cell carcinoma
Get informed consent prior to aspiration
Hematuria after kidney biopsy often resolves in a few days
Free PowerPoint Templates

31. Summary PowerPoint – Ultrasound of the Peripheral Tissues
.pdf of PowerPoint – Ultrasound of the Peripheral Tissues
Dry Lab Handout – Fine Needle Aspiration of the Liver

32. Thomas Nyland, John Mattoon, Eric Herrgesell, Erik Wisner
Acknowledgments
Robert Fulton
Chapter 8: Focused or COAST3 – Reproductive Focused Ultrasound Techniques for the Small Animal Practitioner Editor Greg Lisciandro
Thomas Nyland, John Mattoon, Eric Herrgesell, Erik Wisner
Chapter 3: Ultrasound Guided Biopsy Small Animal Diagnostic Ultrasound Editors Nyland and Mattoon – 3rd Edition 2014