Page 182 - Clinical Manual of Small Animal Endosurgery

170 Clinical Manual of Small Animal Endosurgery

open thoracotomy may be needed for a number of reasons (Radlinsky,
2009), and an emergency situation, such as major intra-thoracic haemor-
rhage, is certainly not the time to learn how to perform a thoracotomy.
Wide clipping, preparation and draping are advisable for even what
is presumed to be a brief and simple procedure such as lung biopsy, in
case of the need for emergency conversion, or a change in procedure or
approach. Human surgical studies have demonstrated that early elective
conversion to open surgery carries a much better postoperative prognosis
that later emergency conversion.

General principles and techniques

While the majority of a procedure such as a lung lobectomy may be
completed thoracoscopically, a mini-thoracotomy is usually still needed
for tissue extraction. Extraction-site metastasis of neoplasia is a real risk,
and efforts to limit the size of an extraction-site wound by pulling tissue
directly through the site should be avoided when possible. Brisson et al.
(2006) reported port-site metastasis of a mesothelioma after just a diag-
nostic thoracoscopy, and this risk needs to be conveyed to owners. Even
if the aetiology of a lesion is infectious rather than neoplastic, this carries
a risk of a wound-site infection.

Instrumentation

A sterile thoracotomy instrument set and rib retractors should always be
available in case of the need for conversion to open surgery. Shorter,
20 cm-long, instruments are very useful for the majority of thoracoscopic
procedures, as the ergonomics of using the longer 30 cm instruments
commonly used in laparoscopy can be very awkward. Standard 30 cm
instruments are rarely truly needed in any but the occasional giant breed.
In small and medium-sized dogs, puppies and cats, as well as for fine
dissection procedures such as vascular ring anomalies, 3 mm diameter
paediatric instruments are ideal. Almost as wide a range of different
instruments are available as in the 5 mm diameter size (Fig. 6.1).

Fig. 6.1 A wide range of 3 mm-diameter paediatric instruments, including
retractors and needle holders, are ideal for thoracoscopy in small patients
or where fine, precise dissection is needed.