SA Neck Surgery

Question 1

Approach to neck surgery.

Answer 1

Positioning:
- dorsal recumbency.
- sandbag under neck.
Familiarity w/ anatomy.
Halstead’s principles:
- Gentle handling of tissue
- Meticulous haemostasis
- Preservation of blood supply
- Strict aseptic technique
- Minimum tension on tissues
- Accurate tissue apposition
- Obliteration of deadspace

Question 2

Neck surgery incision and anatomy.

Answer 2

Linear midline skin incision.
Not too small - want good exposure.
2 paired sets of muscles - gently dissect aside.
Right and left thyroid gland just caudal to the larynx w/ parathyroid glands closely associated.
Trachea obvious.
Oesophagus not that obvious.
- Cervical neck – oesophagus is on LHS.
Left cranial thyroid artery.
Left caudal thyroid artery.
Right cranial thyroid artery.
Caudal laryngeal nerve left.
Right recurrent laryngeal nerve - catastrophic if damaged.
Right vagosympathetic trunk.

Question 3

Stick injury aetiology.

Answer 3

Hx of playing w/ sticks.
Running/stationary.
Aware/unaware.

Question 4

Stick injury clinical signs.

Answer 4

Per-acute, acute, chronic.
Pain - vocalisation, pawing at face.
Drooling.
Unwell due to infection.
Swelling, tracts.

Question 5

Stick injury Dx.

Answer 5

History of seeing it happen or tell-tale signs.
Oral examination - often requires GA.
Imaging - radiography.
– unlikely to identify FB, as often not radiopaque enough but may see subcutaneous emphysema.
– Cervical and thoracic in lateral and DV views.
- CT if available.

Question 6

Initial Tx of stick injury.

Answer 6

Triage and stabilise.
- Fluids etc. – for shock.
- Analgesia.
- Broad spectrum ABX if going to remove FB.
- Wait and speak to referral regarding ABX before giving any if referring.
Exploration under GA - be thorough and complete.
- if not sure, flush – pack airway.
Surgery?

Question 7

Stick injury surgery.

Answer 7

May choose to refer early in case progression into something more complicated and severe.
Lab work - may swab where FB was once removed if chronic or remotely not acute.
- ensures right ABX used.
May choose histopathology but only if infection very severe e.g. mycobacterium.
Debride and copious lavage - to remove smaller FBs and debris.
May or may not choose to close based on:
- location e.g. tongue – leave open, neck – close.
- may or may not insert a drain.
Require lots of analgesia, fluids, targeted ABX, sometimes meds to protect oesophagus.

Question 8

Prognosis of stick injury?

Answer 8

If acute, Px good - low chance of infection, higher chance of successful removal.
If chronic, Px worse - Pre-treatment w/ other ABX may make condition worse.

Question 9

Where does the cervical oesophagus sit in relation to the trachea?

Answer 9

Dorsal and to the left.

Question 10

Types of cervical oesophageal FBs.

Answer 10

Bones.
Rawhide.
Toys.
Fishhooks.
Needles.
String.
Trichobezoar.

Question 11

1. Cervical oesophageal FB clinical signs.
2. Where in the oesophagus do FBs most commonly get lodged?

Answer 11

1. Gagging.
   Dysphagia.
   Retching.
   Regurgitation.
   Vomiting.
   Dyspnoea.
   Swallowing.
2. By the heart base - e.g. westies.
   Distal oesophagus by the cardiac sphincter, just before the stomach.

Question 12

Cervical oesophageal FBs Dx.

Answer 12

Based off Hx - owner may or may not be aware.
Radiographs - contrast may be needed.
– may choose iodine injectable contrast over barium as potential vomit/regurgitation of contrast may lead to aspiration and iodine is less bad in the lungs than barium is.
Ultrasound of the neck.
Referral for advanced imaging, CT scan, fluoro.
Endoscopy - ideal if available – allows safer removal as can be done under visual guidance so less traumatic, allows to assess amount of damage.

Question 13

Cervical oesophageal FBs - medical Tx.

Answer 13

Removal by oesophageal FB forceps.
- can be traumatic.
- relatively risk free if FB in neck.
- higher risk if FB is thoracic.
Removal by endoscopy.

Question 14

Cervical oesophageal FB SX Tx.

Answer 14

Linear midline skin incision in ventral neck.
Dissect muscles aside.
Carefully, push trachea over to RHS for decent access to the oesophagus.
Oesophageal FB should be obvious.

Question 15

Cervical oesophageal FBs complications.

Answer 15

Oesophagitis +/- stricture.
- Tx = ballooning – more inflammation, so may scar again.
Oesophageal perforation.
Oesophageal necrosis +/- late perforation.
Intrathoracic issues.
Sx complications.
- if resection and anastomosis, need referral – do not heal as well as small intestine as no serosal layer in oesophagus –> try to avoid R&A to remove FB, aim for linear incision.
- haemorrhage, infection, healing issues.

Question 16

If cost is not an issue, what is the best imaging modality for a penetrating stick injury?

Answer 16

Computed tonography

Question 17

1. What is a mucocele?
2. Signalment of a mucocele?
3. Clinical signs of mucoceles?

Answer 17

1. Pocket of saliva that is in a location that it is not meant to be.
   From leakage of the salivary duct.
   Mostly idiopathic but sometimes due to trauma.
2. Seen generally in young dogs.
   Seen in mini poodles mostly.
3. Dependent on gland affected which determines location (mandibular, parotid, sublingual, zygomatic). Could be ventral neck, w/in pharynx, under tongue, under ear (parotid), under eye (zygomatic).
   Slow progression of swelling, or acute swelling.
   - can affect swallowing and breathing if oropharyngeal.

Question 18

Tx of mucoceles?

Answer 18

If trauma-induced, small chance that conservative Tx by draining will be enough and the salivary duct can heal on its own.
But, most cases seen require many repeat drainages due to refilling and the SC tissues are becoming more and more inflamed as saliva is a chemical digestive agent.
Likely require Sx, w/ 1-2 drainages.
- Gland removal.
– can go in laterally or ventrally for sublingual/mandibular.
–> raise jugular v, incise (slightly curved) where jugular bifurcates at angle of jaw, dissect down and identify salivary gland (lobulated), exteriorise to allow as much room as possible to maximise chances of cutting out damaged part of duct. Insert drain and close.
- Marsupialisation – for sublingual.
–> cut into pocket of fluid and suture lining of pocket to the tongue tissue.
–> helps drainage of saliva into the mouth.

Question 19

Dx of mucoceles?

Answer 19

Aspiration of swelling - stringy texture of material comes out.
Imaging - does not generally make difference to Tx. Can do contrast to locate leakage, but gland being removed anyway and duct not going to be repaired. Could help to see sialoliths.
Establish which gland is involved (likely submandibular/sublingual.
- Flip animal into dorsal recumbency and mucocele will flop to affected side.
Ranula = mucocele under tongue.

Question 20

Px of of mucoceles depending on choice of Tx.

Answer 20

Intermittent drainage w/o Sx = worse.
Gland removal or sublingual marsupialisation = much better.

Question 21

Which salivary gland is most commonly affected by a salivary mucocele and where does the mucocele sit?

Answer 21

Mandibular, cervical.

Question 22

DAMNIT-V causes for neck masses.

Answer 22

Developmental (congenital cysts.
Metabolic (endocrinopathy e.g. thyroid/parathyroid).
Nutritional (FB abscess)/Neoplastic.
Infectious/Inflammatory/Iatrogenic.
Traumatic (dog attack).
Vascular (haematoma).

Question 23

Neck mass differentials.

Answer 23

FB-induced abscess or sinus tract.
Salivary mucocele.
Oesophageal FB.
Thyroid and parathyroid diseases (dogs - thyroid carcinomas – non-functional
–> can be disastrous if mishandled).
Neoplasia (skin, SC).

Congenital neck cysts.
Lymphadenopathy.
Cervical expanding haematoma.
post-op seroma.