Page 183 - Clinical Manual of Small Animal Endosurgery

Thoracoscopy 171

Endoscope selection

Although a range of different rigid endoscopes can be used for thoracos-
copy, the most useful with the widest range of application is a 5 mm,
30 cm-long endoscope with a 30° viewing angle, often also favoured for
small animal laparoscopy. Although some find the slightly offset view
initially disorientating when placing instruments, this rapidly resolves
after a small amount of use. By rotating the endoscope a wider area can
be examined. The offset view can be used to look around the side of
structures to a degree, as well as allowing visualisation of port placement
and instrument entry in the same side of the chest wall as the optical
port. This limits the risk of levering the endoscope against the adjacent
ribs with resultant risk of injury to the patient and damage to the endo-
scope. The offset angle also allows a more ergonomic horizontal posi-
tioning of the endoscope during procedures.
In small patients, the length of this endoscope can interfere with
instrumentation use and prove awkward. If still using a 5 mm port, the
author finds that a 4 mm, 30°, 18 cm-long arthroscope proves an excel-
lent alternative, with almost as good visualisation and light transmission
as a 5 mm endoscope. This size endoscope, commonly used for human
arthroscopy, is also relatively sturdy. In small patients, use of a dedicated
3 mm, 30°, 18 cm-long endoscope allows the use of only 3 mm ports, and
enables interchange of the endoscope and instruments between the dif-
ferent ports. Alternatively, some prefer the use of a 2.7 mm, 30°, 18 cm-
long endoscope (the so-called universal veterinary endoscope) via a 3 mm
port, as this may already be owned by a practice and used for rhinoscopy
and cystoscopy. This diameter of endoscope is quite delicate and will not
withstand leverage or rough handling, and so is most commonly used
with a protective sheath. Visualisation and light transmission, even with
a 300 W xenon light source, are notably inferior, with at most 20–25%
the illumination of a comparable 5 mm endoscope.
For those surgeons preferring perixiphoid transdiaphragmatic place-
ment of the primary optical threaded cannula in dorsal recumbency
thoracoscopy, a 0° endoscope is needed for safe visual placement of the
port. Good alternative techniques that do not require this specific port
placement for procedures are available (see below).

Reuse of single-use disposable instruments
Some instruments are only available as single-use disposable items. These
are frequently reused by veterinarians to save costs. While not endorsed
by the manufacturers, re-processing (re-sterilisation) of some of these
single-use items is now allowed in human surgery in many countries
according to strict criteria. Items such stapler handpieces are well suited
to reuse, while other items such as haemostatic clip applicators tend to
easily become contaminated with blood internally, and as such are rela-
tively poor candidates for reuse. If reusing single-use items then careful