14. Surgical diseases of the oesophagus. Hiatal hernia. Esophageal feeding tubes.

What are the three parts of the oesophagus?

1. Cervical (lies to the left of the midline)

2. Thoracic (in mediastinum, between v. cava cranialis and aorta)

3. Abdominal (very short)

What are the four layers of the oesophagus?

Mucosa, submucosa, muscularis, and adventitia. NO SEROSA

Why may early fibrin sealing of oesophagostomy sites occur slower than in other areas of the GIT?

Because the oesophagus lacks a serosal layer.

What are the two oesophageal sphincters?

Upper and lower.

What is the function of the upper oesophageal sphincter?

To prevent air from entering the oesophagus during breathing and to prevent reflux of oesophageal contents into the pharynx, guarding against aspiration.

What is the function of the lower oesophageal sphincter?

To prevent reflux of gastric contents back into the oesophagus.

What are the main types of oesophageal surgical intervention?

Oesophagotomy, oesophagostomy, and oesophagectomy.

What is oesophagotomy?

Incision into the oesophageal lumen.

What is oesophagostomy?

Creation of a new opening into the oesophagus for feeding tube placement.

What is oesophagectomy?

Partial resection of the oesophagus.

What is the risk of resecting >3-5cm of oesophagus?

Anastomotic dehiscence (breakdown of the surgical join). If larger resection is necessary, replacement may be required.

Which muscle layers are not incised during oesophageal surgery and why?

The inner circular muscle layers, to prevent damaging the submucosal blood supply.

What is bougienage?

Dilation of a stricture using a probe or dilator of gradually increasing diameter.

What is balloon dilation?

Dilation of a stricture using a balloon catheter.

What are the indications for oesophagotomy?

Oesophageal foreign body and obstruction.

What are the surgical approaches for oesophagotomy?

Cervical, thoracic, and abdominal.

Which approaches require lateral thoracotomy?

Cranial thoracic and caudal oesophagus.

Where is the incision for lateral thoracotomy for access to the cranial thoracic oesophagus?

Choose an appropriate intercostal space according to radiographic location of the abnormality

How is a lateral thoracotomy closed?

1. Place thoracostomy tube 1-2 ICS caudally to incision, or remove air with catheter after rib apposition and muscle closure

2. Preplace 4-8 heavy monofilament absorbable sutures around ribs adjacent to incision

3. Use rib approximator/assistant to appose ribs while tying sutures

4. Suture serratus ventralis, scalaneus, and pectoralis muscles with simple continuous

5. Appose edges of latissimus dorsi muscle with simple continuous

6. Remove air

7. Close subcutaneous tissue routinely

Where is the incision for access to the oesophagus at the heart base?

4th or 5th intercostal space (dissect and retract azygos vein for adequate exposure)

What is the approach for cervical oesophagotomy?

Dorsal recumbency, midline cervical incision beginning at larynx and extending to manubrium.

What structures must be carefully avoided during cervical oesophagotomy?

Thyroid gland and carotid sheath (carotid artery, vagus nerve, and jugular vein).

What is the procedure for cervical oesophagotomy?

1. Move trachea to the right.

2. Retract the paired sternohyoid and sternocephalicus muscles

3. Pack off oesophagus from the rest of the surgical field via moistened laparotomy swab OR simply place two stay sutures above & below (optionally on left & right)

4. Stab incision into oesophagus w/ scalpel blade & extend incision w/ scissors (on foreign body/caudally if trauma/necrosis)

5. Remove foreign body w/ forceps & examine oesophageal lumen for necrotic areas or perforation ⤍ treat if required

6. Suture oesophagus in 2 layers

   1. 1st layer: tunica mucosa & submucosa – simple interrupted (intra-luminal knot)

   2. 2nd layer: adventitia, muscularis & submucosa – simple interrupted (extra-luminal knot)

   3. Sutures 2mm apart, following completion, check for leakage (saline but not performed in practise routinely)

7. Return trachea to normal position

8. Appose muscles & close incision using a simple continuous pattern

9. Appose subcutaneous tissue using a simple continuous pattern

10. Close skin using appositional suture pattern: simple continuous, simple interrupted, intradermal

How is the oesophagus isolated during surgery?

By packing it off from the surgical field with moistened laparotomy swabs or stay sutures.

How is the oesophagus incised during oesophagotomy?

Stab incision with a scalpel blade, extended with scissors.

What is done after suturing the oesophagus?

Checking for leakage (using saline is described but not routinely performed).

What is the post-operative care after oesophagotomy?

IV fluids, nothing PO for 24-48 hours, water after 24 hours, soft food for 5-7 days, and antibiotics.

What are some complications of oesophagotomy?

1. Oesophagitis (due to gastric reflux, post-GA, or aspiration pneumonia)

2. Stricture formation (3-6 weeks post-op).

What are the main signs of oesophageal problems?

Difficulty swallowing (dysphagia) and regurgitation.

How does regurgitation differ from vomiting?

Regurgitation is effortless and has few warning signs, while vomiting is an active process preceded by nausea.

What are the two main reasons for oesophageal regurgitation?

Obstruction and muscular weakness.

How are oesophageal disorders diagnosed?

X-ray with contrast (not barium if risk of rupture), fluoroscopy, endoscopy, CT, clinical signs, and history.

What is a hiatal hernia?

Protrusion of the abdominal oesophagus, gastro-oesophageal junction, and sometimes part of the stomach into the caudal mediastinum.

What are some causes of hiatal hernia?

Congenital abnormalities of the hiatus and trauma.

What are the clinical signs of hiatal hernia?

Regurgitation, vomiting, gastro-oesophageal reflux, hypersalivation, anorexia, respiratory distress, and oesophagitis.

How is hiatal hernia diagnosed?

X-ray with contrast, fluoroscopy, and endoscopy.

How is hiatal hernia treated?

1. Diaphragmatic hiatal reduction

2. Left side gastropexy (most important)

3. Diaphragmatic plication (flattening of the diaphragm).

What are examples of other oesophageal disorders?

1. Obstruction

2. Oesophageal muscular weakness

3. Megaoesophagus

4. Oesophagitis

5. Oesophageal foreign bodies

6. Stenosis/stricture

7. Neoplasia

8. Tracheoesophageal fistula

What are some causes of oesophageal obstruction?

1. Congenital (persistent right aortic arch)

2. Acquired (foreign bodies, strictures/stenosis, neoplasia).

What are some types of oesophageal tumours?

Carcinoma, sarcoma, and leiomyoma.

What are some types of extra-oesophageal tumours that can cause obstruction?

Thyroid carcinoma, pulmonary carcinoma, and mediastinal lymphosarcoma.

What are some causes of oesophageal muscular weakness?

1. Congenital (idiopathic, achalasia)

2. Acquired (myasthenia, hyperadrenocorticism, severe oesophagitis, gastro-oesophageal reflux, myopathies, Spirocerca lupi, botulism/tetanus, lead poisoning, canine distemper, chemicals, and iatrogenic causes like doxycycline, clindamycin, and NSAIDs).

What is megaoesophagus?

Dilation of the oesophagus and loss of motility → food and liquid accumulation.

What are some causes of megaoesophagus?

Congenital or acquired (endocrine disease, myasthenia gravis).

Which breeds are predisposed to megaoesophagus?

Labrador Retrievers, Golden Retrievers, and Persian cats.

What are the clinical signs of megaoesophagus?

Regurgitation, aspiration pneumonia (coughing), and weight loss.

How is megaoesophagus diagnosed?

X-ray with contrast and endoscopy.

How is megaoesophagus treated?

Feeding in an upright position, and prokinetics.

What is oesophagitis?

Inflammation of the oesophagus.

What are some causes of oesophagitis?

1. Infectious agents (Spirocerca lupi)

2. Non-infectious causes (foreign bodies, gastric reflux, certain drugs, cancer, and caustic substances).

What are the clinical signs of oesophagitis?

Asymptomatic presentation, regurgitation, drooling, repeated swallowing, pain, depression, inappetence, trouble eating, and head/neck extension.

How is oesophagitis diagnosed?

Endoscopy (inflamed, red, petechiae, erosions).

How is oesophagitis treated?

H2 blockers, prokinetics, mucoprotectants, analgesia, soft food, antibiotics, and oesophageal feeding tube.

In which animals are oesophageal foreign bodies especially common?

Puppies.

What are some common oesophageal foreign bodies?

Bones, stones, ropes, and threads.

Where are foreign bodies commonly found in the oesophagus?

Where the oesophagus is narrowest: thoracic inlet, base of the heart, and hiatus of the diaphragm.

What are the clinical signs of oesophageal foreign bodies?

Regurgitation immediately after eating, difficulty swallowing, dyspnoea and hypersalivation.

How are oesophageal foreign bodies diagnosed?

History, X-ray with contrast, endoscopy, and palpation.

How are oesophageal foreign bodies treated?

Endoscopic removal via the mouth if not sharp or pushing into the stomach for surgical removal.

What is oesophageal stenosis?

A decrease in the size of the oesophageal lumen.

What are some causes of stenosis?

1. Functional (spastic, oesophagitis)

2. Mechanical

3. Compressive (enlarged lymph nodes, haematoma).

What is the main clinical sign of stenosis?

Regurgitation.

How is stenosis diagnosed?

X-ray with contrast and endoscopy.

How is stenosis treated?

Hydration, dilation with a balloon catheter, or partial oesophagectomy (severe cases).

Are oesophageal tumours common?

No, they are rare.

What are some types of oesophageal tumours?

Squamous cell carcinomas, fibrosarcomas, osteosarcomas, and leiomyomas.

What is a tracheo-oesophageal fistula?

An abnormal connection between the oesophagus and trachea.

What are some causes of tracheo-oesophageal fistula?

1. Congenital (e.g., in Cairn Terriers)

2. Acquired (penetration by a foreign body).

What are the clinical signs of tracheo-oesophageal fistula?

Coughing after eating or drinking, regurgitation, decreased appetite, fever, and lethargy.

How is tracheo-oesophageal fistula diagnosed?

X-ray with or without contrast (use aqueous iodine, not barium, if perforation is suspected).

How is tracheo-oesophageal fistula treated?

Surgery.

When are oesophageal feeding tubes indicated?

When oral food intake is impossible.

What are the types of feeding tubes?

1. Orogastric

2. Nasogastric

3. Oesophageal

4. Gastrostomy

What is the method for inserting an oesophageal feeding tube?

1. Measure feeding tube from insertion point (mid cervical region) to level of 7th-8th ICS and mark it

2. Enlarge/make lateral opening/cut end of tube at oblique angle to encourage smoother flow of blended diet

3. Place curved tip of Rochester-Carmalt forceps through oral cavity into the oesophagus to the level of the left mid-cervical region (half way between mandible and shoulder)

4. Palpate the tip through the cervical skin, make a small incision and push forceps through oesophageal wall, sub cut and skin

5. Grab tube with forceps and pull out through the oral cavity

6. Redirect tube into the oesophagus, confirming placement by location of premarked area

7. Secure the tube to the cervical skin with a Chinese finger trap suture, loosely bandage the area and cap the end of the tube

What are some contraindications for oesophageal feeding tube placement?

Oesophageal dysfunction (megaoesophagus, stricture, oesophagitis).

Where is an oesophageal feeding tube placed?

Left mid-cervical region.

How is an oesophageal feeding tube secured?

With a Chinese-finger-trap suture.

How is the length of an oesophageal feeding tube determined?

From the placement site to the 7th-8th intercostal space.

How are animals fed through an oesophageal tube?

Small amounts of liquid food, followed by water