Introduction

• For use in the investigation of any accessible mass or cystic lesion and:

Liver

• Jaundice.
• Unexplained raised liver enzymes.
• Abnormal appearance of liver on ultrasonographic examination.
• Diffuse liver disease Liver: chronic disease - overview (inflammatory, infiltrative, neoplastic).
• Mass lesions.
• Aspiration of bile.

Kidney

• Diffuse diseases (acute or chronic nephritis).
• Protein losing nephropathy.
• Mass lesions.

Spleen

• Useful for solid masses.
  
  Avoid cavitatory lesions.

Gastrointestinal tract

• Mass lesions.

Thorax

• Mass lesions of chest wall, mediastinum or lung.
• Aspiration of thoracic effusions.

Lymph nodes

• Lymphadenopathy Lymphadenopathy.

Prostate

• Diffuse or multifocal non-cystic prostatic disease Prostate disease.
• Solid prostatic masses.
• Aspiration of cystic structures for diagnostic or therapeutic purposes.

Advantages

• Low cost.
• Minimally-invasive.
• Rapid.
• Straightforward in hands of experienced operator.
• Short time requirement.
• Often performed without general anesthesia.
• Minimal risk of complication.

Disadvantages

• Requires patient's coat to be clipped.
• Difficult to obtain samples in obese patients, from deeply located structures, highly vascularized lesions and in the presence of a large amount of fluid.
• Samples may be non-diagnostic or non-representative of disease process.
• Requires significant operator skill.
• General anesthesia General anesthesia: overview may be required.

Potential problems

• Seeding of tumor with bladder carcinomas Bladder: neoplasia.
• Hemorrhage:
  • Hemorrhage may be more likely with neoplastic lesions.
  • Complications more likely with thrombocytopenia Immune-mediated thrombocytopenia , prolonged PT (dogs) Hematology: prothrombin time and APTT (cats).
• Penetration of other viscera.
• Inadequate patient restraint:
  • Movement could result in laceration of vessels or organ.
• Operator inexperience.
• Excess intestinal gas or large gall bladder may limit visibility of target tissue.
• Inadequate equipment (needle diameter too small or too short).
• Failure to visualize needle due to improper technique or patient factors (obese, excessive respiratory movement).
• Target may be too small to safely obtain sample (particularly in small dogs and cats).
• Non-diagnostic sample:
  • Hemodilution - especially spleen and liver.
  • Fibrotic or cirrhotic livers may produce poor samples due to poor exfoliation.
  • Sample size may be too small.
  • Sample not from affected area (multifocal disease).

Alternatives

• Exploratory surgery, laparoscopy, ultrasound-guided biopsy Biopsy: ultrasound-guided.

Equipment

Patient preparation

technique

Complications

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Nyland T G, Wallack S T, Wisner E R (2002) Needle-tract implantation following us-guided fine-needle aspiration biopsy of transitional cell carcinoma of the bladder, urethra, and prostate. Vet Radiol Ultrasound 43 (1), 50-53 PubMed.
• Bennett P F, Hahn K A, Toal R L et al (2001) Ultrasonographic and cytopathological diagnosis of exocrine pancreatic carcinoma in the dog and cat. J Am Anim Hosp Assoc 37 (5), 466-473 PubMed.
• Szatmári V, Osi Z, Manczur F (2001) Ultrasound-guided percutaneous drainage for treatment of pyonephrosis in two dogs. JAVMA 218 (11), 1796-1799, 1778-1779 PubMed.
• Samii V F, Nyland T G, Werner L L et al (1999) Ultrasound-guided fine-needle aspiration biopsy of bone lesions: a preliminary report. Vet Radiol Ultrasound 40 (1), 82-86 PubMed.
• Wood E F, O'Brien R T, Young K M (1998) Ultrasound-guided fine-needle aspiration of focal parenchymal lesions of the lung in dogs and cats. J Vet Intern Med 12 (5), 338-342 PubMed.
• Barr F (1995) Percutaneous biopsy of abdominal organs under ultrasound guidance. J Small Anim Pract 36 (3), 105-113 PubMed.
• Léveillé R, Partington B P, Biller D S et al (1993) Complications after ultrasound-guided biopsy of abdominal structures in dogs and cats: 246 cases (1984-1991). JAVMA 203 (3), 413-415 PubMed.
• Yamamoto K, Ishiyama N, Yamaga Y et al (1991) Ultrasound-guided techniques for biopsy of the kidney of the medium-sized dog. J Vet Med Sci 53 (2), 345-346 PubMed.
• McNamara M P Jr. (1989) Percutaneous procedures guided by color-flow Doppler sonography. AJR Am J Roentgenol 152 (5), 1123-1125 PubMed.
• Smith S (1989) Ultrasound-guided biopsy. Semin Vet Med Surg (Small Anim) 4 (1), 95-104 PubMed.
• Smith S (1985) Ultrasound-guided biopsy. Vet Clin North Am Small Anim Pract 15 (6), 1249-1262 PubMed.