Ultrasound Guided Biopsies Wendy Blount, DVM Free PowerPoint Templates

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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