ATTI 42째 completo
12-02-2001
14:31
Pagina 306
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One contraindication for performing a biopsy is not know ing the anatomic sites that may result in serious problems. In this case, a nasal biopsy is obtained with a tube attached to a syringe. The cribriform plate (A) is the anatomic site of great importance when performing a nasal biopsy.
2. Using a 25 gauge needle, approximately 2 to 3 mls of the local anesthetic agent, lidocaine, are injected in and around the site where the bone marrow needle is to be introduced. Care is taken to deposit lidocaine in and around all of the tissues that extend from the skin to the bone. 3. The biopsy area is scrubbed a final time after the lidocaine is injected. A surgical drape can be applied for sterility. 4. The bone marrow site is identified, the skin is stretched between the thumb and index finger, and a small stab incision is made with a number 11 surgical blade in the area blocked with lidocaine. 5. The bone marrow needle with the stylette in place is advanced through the stab incision in the skin, subcutaneous tissue, and muscle down to the bone. It is crucial to keep the stylette in place because it has a tendency to back out during the procedure. A 1 to 1.5 inch long, 16 gauge Illinois or Rosenthal bone marrow needle is preferred for dogs, and a 1 inch long, 18 gauge Illinois or Rosenthal needle is preferred for the cat. After a sample is obtained for cytologic evaluation, if a biopsy is required, a Jamshidi needle is utilized . 6. With the stylette is place, the bone marrow needle is advanced into the bone using a corkscrew motion. The instrument should not be allowed to wobble and the instrument should be fixed firmly into bone like a nail that has been securely hammered into wood. When the needle is firmly fixed in the bone, the stylette is removed and the syringe is affixed. Many clinical pathologists suggest rinsing the syringe and bone marrow needle with
42째 Congresso Nazionale SCIVAC
One contraindication for performing a biopsy is not know ing the anatomic sites that may result in serious problems. In this case, a nasal biopsy is obtained with a tube attached to a syringe. The cribriform plate (A) is the anatomic site of great importance when performing a nasal biopsy.
EDTA before the procedure to reduce clotting of the bone marrow sample. 7. The bone marrow sample is then aspirated briskly into the 12 ml syringe; usually 1 ml is adequate. The aspiration may be accompanied with a few seconds of pain, but this cannot be pr evented. 8. If a sample is not obtained, the stylette is replaced in the bone marrow needle and the instrument is then advanced further into the bone for a second attempt at aspirating marrow contents. 9. Once marrow has been obtained, smears are prepared. This can be done a number of ways: Fine needle aspiaration without (A and B above) or without (C above) the syringe attached to the needle is an important clinical tool for obtaining cells for a diagnosis.
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Withrow SJ: Biopsy Principles, in Withrow SJ, MacEwen EG (eds): Clinical Veterinary Oncology, Philadelphia, JB Lippincott Co. 1989, pp 53-57. Morrison WB, Hamilton TA, Hahn KA, Richardson RC, Janas W: Diagnosis of Neoplasia. In Slatter D (ed): Textbook of Small Animal Surgery (2nd ed), Philadelphia, WB Saunders Co, 1993, pp 20362048. Avis F: Lymph Node Biopsy, in Wittes RE (ed) Manual of Oncologic Therapeutics 1991/1992. Philadelphia, JB Lippincott Co. 1991, pp 8-9.