Page 133 - Clinical Manual of Small Animal Endosurgery

Diagnostic Laparoscopy 121

Fig. 4.13 Margin of liver after removal of two biopsies. Note that almost
no bleeding has occurred.

therefore small samples taken at the edge of the lobes may not reflect
deeper lesions.
The biopsy forceps are inserted through the operating port, directed
toward the area to be sampled, and the tissue is grasped. The forceps
are kept in position for 15–30 s, and then the tissue is gently twisted and
pulled to retrieve the sample. In this way haemostasis is produced, dimin-
ishing the haemorrhage from the biopsy site. The area is closely moni-
tored until haemorrhage stops (Fig. 4.13). This usually occurs within
2–3 min; if bleeding is more than expected, pressure can be applied to
the biopsy site using the palpation probe or the tip of the laparoscope.
If the haemorrhage persists, a haemostatic agent such as absorbable gela-
tine felt can be applied into the tissue defect and pressure applied for
approximately 1 min.
Using a pre-tied loop ligature or extracorporeally assembled loop liga-
ture to obtain biopsy samples is recommended in case haemorrhage is
anticipated, such as in patients with coagulopathies, severe hepatic failure
or highly vascular lesions. This technique requires one additional operat-
ing port for introducing the loop, which is manipulated around the biopsy
site (usually the tip of a lobe). With a blunt probe or grasping forceps the
liver lobe is elevated, so the loop can be positioned and tightened.
The friable liver parenchyma is crushed, and the knot securely ligates
the blood vessels and bile ducts, thus allowing the sample to be collected
with laparoscopic scissors from the liver tissue distal to the loop.
A needle-core biopsy technique can also be used to obtain samples of
the liver, but due to the restricted amount of tissue obtained this method
is most often used to obtain samples of focal vascular liver masses. The
biopsy needle can be inserted percutaneously through a small puncture just
lateral to the xiphoid cartilage and manipulated under direct visualisation.