Gastroenterology Pt. 4

Question 1

CONGENITAL ESOPHAGEAL DISORDERS (5)

Answer 1

¡ Vascular ring anomalies
¡ Esophageal diverticulum
¡ Sliding & paraesophageal hiatal hernias
¡ Congenital megaesophagus (motility disorder)
¡ Esophageal achalasia (lower esophageal sphincter does not relax)

Question 2

congential esophageal disorders diagnosis

Answer 2

¡ Thoracic radiographs
¡ Barium swallow (Fluoroscopy best)
¡ Endoscopy

Question 3

treatment for primary esophageal motility disorder

Answer 3

¡ Gravity feeding
¡ Bailey chair
¡ Small frequent meals

Question 4

treatment for achalasia

Answer 4

¡ Sildenafil
¡ Surgery

Question 5

treatment for congenital esophageal disorders aside from primary motility disorders and achalasia

Answer 5

surgery

Question 6

causes of acquired megaesophagus

Answer 6

¡ Esophageal motility ± swallowing disorder
> Occasionally just swallowing disorder (dysphagia)

¡ Idiopathic
> Most common diagnosis

¡ Myasthenia gravis
> Focal or generalized ± thymoma in cranial
thorax
> Diagnosis - acetylcholine receptor antibody titre

¡ Previous GDV and gastropexy
¡ Classical and atypical Addisons
> ACTH stimulation test
¡ Hypothyroidism?
¡ Esophagitis?
¡ Dysautonomia – dysuria, dry mm, abnormal PLRs
¡ Other causes

Question 7

main complication of acquired megaesophagus

Answer 7

high risk for aspiration pneumonia

Question 8

diagnostics for acquired megaesophagus

Answer 8

¡ Radiograph

¡ Endoscopy

¡ Work-up for underlying disorder

Question 9

consideration when using radiographs to diagnose acquired megaesophagus

Answer 9

avoid barium if possible (aspiration risk)

Question 10

pros and cons of endoscopy to diagnose acquired megaesophagus

Answer 10

• Cannot judge motility
• Useful to identify FB, stricture, esophagitis
• Increased risk of aspiration after anesthesia

Question 11

underlying disorder work-ups that we can do to investigate acquired megaesophagus

Answer 11

¡ Acetylcholine receptor antibody titer (Myasthenia gravis)
¡ Resting cortisol/ACTH stimulation test (Hypoadrenocorticism)
¡ Thyroid profile

Question 12

acquired megaesophagus treatment

Answer 12

¡ Treat underlying cause if possible
> eg. myasthenia gravis > pyridostigmine

¡ Gastrotomy tube

¡ Metoclopramide/cisapride
> Increase smooth muscle tone of LES
> Promote gastric emptying
¡ Esophageal suctioning
¡ Sildenafil?

Question 13

myasthenia gravis treatment? what not to use?

Answer 13

• Pyridostigmine (cholinergic drug)
• ± Immunosuppression
• Not prednisone
  > Muscle weakness & aspiration pneumonia

Question 14

acquired megaesophaus prognosis

Answer 14

¡ Idiopathic close to 0% survival
¡ Myasthenia gravis – 20-40% survival
¡ Addisons – 100% survival
¡ Post GDV and other?

Question 15

causes of acute esophagitis

Answer 15

¡ Esophageal FB
¡ Regurgitation under anesthesia
¡ Caustic substance
¡ Severe protracted vomiting
¡ Small intestinal ileus

Question 16

signs of acute esophagitis

Answer 16

¡ Regurgitation
¡ Depression (painful)

Question 17

causes of chronic esophagitis

Answer 17

• Gastroesophageal reflux disease (GERD)
  > Not as common a primary disorder as in humans
  > Reduced LES tone
  > R/O hiatal hernia
• Persistent vomiting

Question 18

medical treatments for chronic esophagitis

Answer 18

• Gastroprotectants (sucralfate, omeprazole…)
• Treat cause of vomiting

Question 19

types of esophageal neoplasias

Answer 19

¡ Spirocerca lupi (nematode) sarcoma
¡ Primary esophageal carcinoma
¡ Invasive thyroid or pulmonary tumour

Question 20

diagnosis for esophageal neoplasia

Answer 20

¡ Plain radiographs ± barium
¡ Endoscopy
> Cannot normally biopsy esophagus by endoscopy
> Sometimes can biopsy a mass

Question 21

most common cause of esophageal stricture? when do we see clinical signs?

Answer 21

Most commonly caused by gastroesophageal reflux during general anesthesia
¡ Reported to have preceded stricture formation in up to 65% of cases
¡ Clinical signs typically reported 7-8 days post anesthesia

Question 22

how often are esophageal strictures alone? how often are there multiple?

Answer 22

¡ Single strictures identified in 80%, 2 or 3 in remaining 20%

Question 23

where are most esophageal strictures located?

Answer 23

¡ 80-90% located in intrathoracic esophagus

Question 24

esophageal stricture treatment options; how do they work, pros and cons

Answer 24

¡ Balloon dilation
> Theoretical advantage: forces applied in
a radial stretch
> Balloon kept inflated for 60-90 seconds and then deflated

¡ Bougienage
> Longitudinal forces applied
> Dilation with mechanical dilators (bougies)

¡ With either treatment:
> Multiple treatments often required
> Risk of esophageal perforation

• Esophageal balloon dilation feeding tube
  ¡ Twice daily at home dilations for 6
  weeks
  ¡ In one study, 92% had improvement
  ¡ Major complications in 17%

Question 25

reasons for regurgitation in cats (5)

Answer 25

¡ Esophageal FB, occasionally large furballs
¡ Caustic - doxycycline
¡ Esophageal stricture
¡ Squamous cell carcinoma
¡ Megaesophagus – can affect:
> Proximal 2/3 striated muscle
> Distal 1/3 smooth muscle
> Whole esophagus

Question 26

List 3 of the main factors in the gastric mucosal barrier:

Answer 26

¡ Bicarbonate-rich mucus
¡ Mucosal cells
¡ Blood supply

Question 27

Which of the following is not a potential cause of secondary megaesophagus?
¡ A) Hyperadrenocorticism
¡ B) Hypothyroidism
¡ C) Myasthenia Gravis
¡ D) Hypoadrenocorticism

Answer 27

¡ A) Hyperadrenocorticism

Question 28

Identify the true statement in regards to esophageal strictures
¡ A) Forces applied in balloon dilation are applied longitudinally and those with bougeniage are applied radially
¡ B) Patients that develop esophageal strictures subsequent to GER during anesthesia will usually show signs within 1- 2 days afterwards
¡ C) A single treatment (with either balloon dilation or bougenieage) is usually sufficient to treat esophageal strictures
¡ D) Esophageal perforation is a risk with treatment of esophageal strictures

Answer 28

D) Esophageal perforation is a risk with treatment of esophageal strictures