Page 185 - Clinical Manual of Small Animal Endosurgery

Thoracoscopy 173

nulae are often too long to be ideally suited to thoracoscopy. Valves
should be removed to prevent the risk of a tension pneumothorax devel-
oping during anaesthesia, interfering with adequate lung ventilation.
These rigid cannulae, particularly if threaded, also carry a risk of trau-
matising the intercostal vessels and nerves in medium-sized and smaller
animals. If care is not taken when angulating instruments there is a risk
of the applied leverage through the larger 10–15 mm cannulae causing
inadvertent rib fractures. Sharp-tipped trocars used for blind (Veress
needle) laparoscopic access are unsuitable for inserting cannulae into the
chest, as these carry a high risk of causing lung laceration or other injury.
Ports of 3 mm are useful in small paediatric patients, or for fine dis-
sections. These are currently only available from a small number of
manufacturers. The author has a particular preference for YelloPort+
cannulae (Surgical Innovations). These are reusable, but are plastic and
light weight. Instead of being threaded, they have a finely grooved shaft
that is both atraumatic and provides good retention in port sites (see Fig.
6.3). Ports of 3 mm are similar in diameter to many small-gauge chest
drains, and so there is minimal risk of developing pneumothorax post-
operatively, eliminating the need for postoperative chest drain insertion.
Perpendicular cannula ends are preferable to angled ends, which result
in a longer portion of cannula protruding into the chest cavity. Even
though this may make a difference of only 3–5 mm, this can be sufficient
to interfere with the jaw movements of instruments when operating in
a very small space, such as when performing a vascular ring anomaly in
a 2 kg puppy.

Fig. 6.3 These 3 mm reusable ports (YelloPort+) are useful in small
patients or for fine dissection. These plastic ports are light weight, and
instead of being threaded they have a finely grooved shaft that is both
atraumatic as well as providing good retention in port sites.