Page 14 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 1 · Surgical principles and instrumentation

Endoscopy Diagnosis, staging, prognosis and intended
Direct inspection of the oral cavity and respiratory tract procedure
VetBooks.ir bronchoscopy, using a flexible or rigid endoscope, is the At this point a definitive diagnosis should have been
under general anaesthesia via rhinoscopy, laryngoscopy or
achieved, along with an assessment of the severity of the
most common means of achieving a definitive diagnosis of
disease or staging, and the presence of concurrent disease.
disorders affecting these regions.
The most useful endoscopes include: A plan should be developed to outline the following:
• Pre-anaesthetic stabilization
• A small-diameter rigid endoscope for rhinoscopy and • Anaesthesia
otoscopy • Diagnostic procedures to be performed
• A small-diameter flexible endoscope for • Surgical procedure to be performed
nasopharyngoscopy • Perioperative and postoperative analgesia
• A laryngoscope for laryngoscopy • Postoperative care and monitoring
• A larger-diameter rigid or flexible endoscope for • Postoperative nutritional support
tracheoscopy and bronchoscopy • Expected long-term prognosis.
• A larger-diameter flexible or rigid endoscope for
oesophagoscopy. The diagnosis, potential complications and expected
long-term prognosis should be communicated to the
The perioperative use of anti-inflammatory doses of client. It should be ensured that the client understands
corticosteroids (e.g. dexamethasone sodium phosphate the nature of the disease and its current severity and has
0.1–1 mg/kg i.v. or methylprednisolone sodium succinate reasonable expectations for the long-term outcome.
0.5–2 mg/kg i.v.) may help to reduce the oedema asso-
ciated with such diagnostic interventions, particularly
intra aryngeal procedures. In animals that represent an Anaesthesia and analgesia
l
anaesthetic risk, diagnostic endoscopy should be followed
with a definitive surgical procedure under the same anaes- All dogs and cats undergoing head, neck and thoracic
thetic, whenever possible. surgery require cardiovascular support in the form of intra-
venous fluid therapy and must be provided with an appro-
Thoracoscopy: Advances in equipment and expertise priate level of anaesthesia and analgesia. These techniques
have allowed the development of thoracoscopy as a suit- are discussed in detail in the BSAVA Manual of Canine
able diagnostic and therapeutic technique for diseases of and Feline Anaesthesia and Analgesia and the BSAVA
the thoracic cavity. The entire thoracic cavity may be vis- Manual of Canine and Feline Surgical Principles.
ualized from appropriately placed portals and this allows
evaluation of the pleura, pleural space, mediastinum,
lungs, heart and pericardium, trachea and thoracic duct. Patient positioning
For each surgical procedure there is an optimal position
Fine-needle aspiration and biopsy for the patient to allow the best access to, and visibility of,
A cytological or histological diagnosis for all lesions of the surgical site, to create tension on the tissues to be
unknown aetiology should ideally be obtained prior to incised, thus allowing safer dissection, and to allow safe
planning treatment. Exceptions to this include where it will anaesthesia and monitoring. Positioning the patient for
not change the treatment plan (e.g. lung lobectomy for a some procedures, particularly those that require access
solitary lung mass) or where it will not change the client’s via the mouth (Figure 1.2), may be awkward, but it is criti-
willingness to treat the patient. cal that the best access is gained and that the patient
stays in this position. A little extra time spent ensuring
Fine-needle aspiration cytology is a simple and quick
procedure. It is suitable for the diagnosis of external proper patient positioning will pay dividends.
lesions (e.g. cutaneous tumours) at first presentation and Positioning
1.2
for deeper lesions under ultrasound guidance (e.g. cranial of a Bulldog
mediastinal mass). Fine-needle aspiration cytology may for an oral approach to
differentiate tumours from inflammatory and other lesions the airway.
(e.g. salivary mucocele). It may also differentiate tumour
types (e.g. epithelial tumour, mesenchymal tumour or
round cell tumour) and determine chronicity (e.g. acute
versus chronic inflammation).
Biopsy preserves tissue architecture and should yield a
definitive diagnosis. It should be performed preoperatively
if fine-needle aspiration cytology cannot be performed or
is non-diagnostic. Tissue samples may be obtained via
grab biopsy with forceps (e.g. nasal passages), skin biopsy
punch (e.g. cutaneous masses), Tru-cut biopsy needles
(e.g. subcutaneous mass lesions) and wedge incision (e.g.
oral masses). Biopsy should be performed postoperatively
on all excised tissue where a definitive diagnosis has not
been achieved preoperatively, and on all tumours, even
those with a preoperative diagnosis, to assess tumour
type, grade, degree of vessel and lymphatic invasion, and
margins of excision.

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