Page 127 - Clinical Manual of Small Animal Endosurgery

Diagnostic Laparoscopy 115

Fig. 4.8 Secondary port insertion: the instrument is passed through the
secondary trocar under direct observation. Photograph courtesy of Mr P.J.
Lhermette.

localisation of the entry site on the video monitor. The second port is
established with the technique previously described, and the surgeon
monitors the entry into the abdomen with the telescope (Fig. 4.8). This
ensures that the trocar will not cause trauma to underlying organs. Simi-
larly, instruments are never blindly inserted into the abdomen but directed
towards the area of interest under visual monitoring. The telescope is
positioned so that the tip of the cannula is in the field of view, and the
instrument is inserted, closed, while its movement to the operative site
is followed on the monitor. Only when the operative site is reached are
the jaws of the instrument opened. Attention must be paid not to with-
draw cannulae from the abdomen, as this would cause difficulties in
maintaining the pneumoperitoneum, and consequently in reinserting
them. This may occur more frequently in smaller patients, or when the
abdominal wall is particularly thin.
Systematic examination of the abdomen is then performed, to detect
any abnormalities. A blunt calibrated probe (5 mm in diameter, with 1 cm
marks along the shaft) is usually employed to aid in manipulating organs
and retract omentum. Retraction can be also achieved by tilting the table
or rotating the animal on one side. This allows gravity to shift viscera
away from the field of view and improves visibility. The table should
never be tilted more than 15° to prevent complications.
If a significant amount of ascites is present, at the beginning of
the procedure as much fluid as possible is removed. This is accom-
plished with fenestrated suction probes introduced through a secondary
portal. However, abdominal fluid is best drained preoperatively, as
the presence of fluid, often cloudy, greatly compromises visualisation of
intra-abdominal structures. Furthermore, abdominal organs will also