Page 585 - Small Animal Internal Medicine, 6th Edition

CHAPTER 34 Diagnostic Tests for the Hepatobiliary and Pancreatic System 557

animal’s previous investigations. Serious consideration Bard Biopty-Cut biopsy needle, Bard Biopsy Systems, Tempe,
should also be given to placing a feeding tube at the same Ariz) versions of this instrument are also available. These
VetBooks.ir time to avoid a second anesthetic for feeding tube placement biopsy needles are intended for single use. The automatic
biopsy instrument or semiautomatic biopsy needle device
at a later date should this prove necessary.
Laparotomy and laparoscopy require a general anesthetic.
A few dogs with end-stage chronic hepatitis and cats with can be used to obtain liver biopsies in dogs, but only the
semiautomatic biopsy needle device should be used in cats.
acute hepatic lipidosis are very poor anesthetic risks and One study identified a high risk of fatal complications (unex-
likely to die if anesthetized for any procedure. These cases pected fatal shock reaction) when an automatic biopsy
should have fine-needle aspiration or Tru-Cut biopsies under instrument was used to obtain liver biopsies in cats (Proot
careful sedation or supportive care until their clinical condi- and Rothuizen, 2006).
tion improves enough to allow the use of a safe general Biopsy can be done of any palpably enlarged lobe as long
anesthetic. as care is taken to angle the needle to avoid puncturing the
US-guided Tru-Cut biopsies may be performed under gallbladder. Usually the animal is placed in right lateral
sedation or general anesthesia. If a concurrent gallbladder recumbency for this purpose, and biopsy of the left lateral
aspirate is being obtained, a general anesthetic is preferred lobe is done. Elevating the head and thorax slightly may
to allow breath-holding during the procedure. Biopsy can be assist in presenting the liver to the operator. Two or three
performed blindly if the cat or dog has generalized hepato- complete core specimens are obtained; if indicated, one core
megaly and the operator is confident of the path of the specimen is placed in a sterile container for culture and
needle. The most common needle biopsy instruments are the sensitivity testing. Each of the remaining core specimens is
Tru-Cut (Cardinal Health, Dublin, Ohio) and Jamshidi placed on a piece of stiff paper (e.g., filter paper) in correct
Menghini (Cardinal Health, Kormed, Seoul, Korea) needles. orientation (Fig. 34.19) before immersion in fixative for his-
The Jamshidi Menghini biopsy needles can be operated with tologic examination and/or special testing.
one hand, and aspiration is used to sever and contain the After biopsy, a small bandage is applied to keep the site
specimen within the barrel of a 6- or 12-mL syringe. The clean during recovery, and the animal is placed in a position
Tru-Cut needle requires two hands to operate and relies on to allow its body weight to compress the region of the biopsy
the tissue falling into the specimen trough and then being sites in the liver (e.g., left lateral recumbency). Consideration
severed by the sharp outer cannula (Fig. 34.18). One-handed, should be given to postoperative analgesia; puncture of the
semiautomatic (e.g., Tenmo Evolution biopsy needle, Cardi- liver capsule can be painful. The animal should be monitored
nal Health; Vet-core biopsy needle, Smiths Medical, Dublin, carefully for any evidence of hemorrhage for several hours
Ohio; Global Veterinary Products, Amarillo, Tex) and auto- after the procedure. As long as the biopsy procedure pro-
matic (e.g., Pro-Mag Ultra Automatic biopsy instrument, ceeded smoothly and without unpleasant surprises (animal
Angiotech, Wheeling, Ill; Bard Biopty biopsy instrument and awake and struggling), only basic monitoring of mucous

A B

FIG 34.18
(A) Tru-Cut biopsy needle with the specimen trough exposed (left) and then covered by
the sharp outer cannula (right). (B) Liver tissue filling the specimen trough (between
arrows).