Page 188 - Clinical Manual of Small Animal Endosurgery

176 Clinical Manual of Small Animal Endosurgery

reloads being available the cutting blade and anvil are actually in the
handpiece. The blade will become blunt after a few firings, meaning that
the handpiece is not suitable for reuse, and notably increasing a proce-
dure’s cost. Reloads are also limited to the same cartridge length as the
handpiece (30, 45 or 60 mm), requiring increased stocking expense,
although different staple-length reloads for different tissue thicknesses
can be used with the same handpiece.
Articulated-staple cartridges (Endo GIA Roticulator, Covidien) are
marginally more costly than straight-staple cartridges, but much better
suited to thoracic surgery, where limited space and limited manipulation,
for example of a lung hilus, is possible. Occasionally tissue sectioning is
not complete, or staple cartridge misfiring may occur.
For this reason at least two staple cartridges should be available when
planning their use in a procedure.

Knot pushers
A knot pusher is highly recommended for placing extracorporeal knot
ligatures, such as for peripheral lung biopsies, or for vascular ligations.
A closed-end knot pusher (i.e. with a hole at the distal end) is preferable
to the open or grooved knot pusher most commonly offered by veteri-
nary suppliers, which is more difficult to manipulate, and doesn’t allow
as precise knot positioning. Knot pushers are available in 5 mm and
paediatric 3 mm diameters.

Retractors
Lung retraction is more difficult and limited in comparison to open
thoracic surgery, where one can pack the lungs away with the use of
large moist swabs, or simply ‘grab something and shove it to the side’.
Fan retractors are the most commonly available retractors, but are
10 mm in diameter, needing a large port for insertion. These also risk
traumatising the lung or other delicate structures when closing the blades,
or on the edges of the fan blades, which in reusable retractors may
become sharp over time. Disposable fan retractors (Endo Retract, Covi-
dien) also add to procedure costs. Although reusable flexible 5 mm
retractors such as those made by Snowden Pencer and Surgical Innova-
tions are relatively expensive instruments for veterinary surgeons, they
are much less traumatic, and easier to use once formed, to hold lung out
of the way. Smaller, circle-shaped retractors or standard liver-retractor
shapes are available. Their main disadvantage aside from cost is the rela-
tively long lead-in length of the unformed retractor head, which makes
them unsuitable for insertion into small chests, or small spaces.
A simple blunt palpation probe may be sufficient for lung retraction
in some procedures, such as vascular ring resections, if combined with
suitable ventilator settings (Fig. 6.5). To a degree some retraction can
also be attained via positioning and gravity, just as for laparoscopy.
Ventilation of a single lung, or low-pressure carbon dioxide insufflation