Page 289 - Clinical Manual of Small Animal Endosurgery

Small Exotic Animal Endosurgery 277

ment tips may be too crude to dissect delicate structures; in contrast, 3 mm
paediatric instrumentation has the advantage of having fine tips, and also
shorter jaws for working in small spaces. The shorter 20 cm length
also offers better ergonomics than standard 30–45 cm-long instrumenta-
tion, which again helps with precise surgery in restricted spaces. In the
smallest patients, even shorter instrument lengths would be desirable, but
are not commonly commercially available. In laboratory rat surgical
studies small arthroscopy instruments have been used without ports, due
to their short shaft lengths, and this may perhaps be applicable for simple
procedures in small mammals when instrument changes are not needed.
These patients have thin body walls, which are poor at retaining
smooth shaft cannulae when changing instruments. Some 3 mm cannulae
have a thick silicon valve, which has higher friction against the instru-
ment shaft than the cannula shaft has against the port site. This results
in frustrating motion at port sites during a procedure, and even in port
loss, with subsequent deflation of the abdomen or coelom. Threaded
cannulae can be used, but these are more traumatic, and result in a larger
wound defect. An alternative is to use cannulae with finely grooved shafts
and a low-friction disposable silicon valve. These are available in 3 and
5 mm as well as larger sizes (YelloPort+, Surgical Innovations).
Lightweight, clear plastic drapes are an obvious advantage in small
exotic pets. Endosurgery needs wide sterile draping if light, camera and
electrosurgery cables are not to drag from non-sterile to sterile draped
areas, even if the patient is small and completely covered by the drape.
This of course limits the anaesthetist’s access to and visualisation of the
patient during surgery (Fig. 10.3).

Fig. 10.3 Transparent drapes help the anaesthetic monitoring of small
mammals such as this rabbit during laparoscopy. The finely grooved
YelloPort+ cannulae are smaller and less traumatic than threaded cannulae,
and have better tissue retention in small mammals with their thin body
wall, due to low instrument friction with a lubricated silicon valve.