Esophageal Disease Flashcards
GI tract:
What 3 functions does the GIT have?
- digest food
- absorb nutrients
- eliminate waste
What is the structure of the esophagus?
- upper esophageal sphincter pushes bolus into esophagus
- lower esophageal sphincter pushes bolus into stomach
What are 2 sources of esophageal motor innervation? What is normal motility like?
- spinal nerve in skeletal muscle segments - vagus nerve causes esophagus to constrict and push bolus through
- myenteric plexuses along the whole length - control/coordination
reflexive - once pharynx is engaged, the rest is beyond conscious control
What is primary and secondary peristalsis?
PRIMARY - waves of contraction push bolus into stomach, elicited by swallowing
SECONDARY - bulging of the esophageal wall due to a bolus stuck in the lumen induces more contraction to move it into the stomach
What 2 structures are found in the esophageal wall?
- MANY submucosal mucous glands - mucus facilitates swallowing
- stratified squamous epithelium - allows for wear and tear with each swallow
What are the 2 species differences in esophageal wall musculature?
- all skeletal - dog, ruminant
- cranial 2/3 skeletal, distal 1/3 smooth - cat, horse
muscle disorders also affect the stomach - polymyositis, myasthenia gravis
How do the esophageal sphincters lie at rest? What is the difference between the upper and lower esophageal sphincters?
held tonically closed to prevent air from getting in the esophagus - must relax in response to swallowing
UPPER - skeletal muscle (cricopharyngeus) + cartilage (cricoid); prevents air entry into the esophagus during breathing and reflux into the pharynx during swallowing
LOWER - smooth muscle; proximal to and overlaps gastric cardia, prevents reflux of acidic gastric contents into the esophagus
What are 3 common etiologies of esophageal dysfunction?
- myasthenia gravis - blocks Ach, causes flaccid paralysis –> megaesophagus, drooling, regurg
- sphincter tonicity or dyssynergia - cricopharyngeal aclasia, choking, dysphagia, regurg
- FB/stricture - gasping for air, choking, drooling, regurg, painful swallowing
regurgitation in common
What is the hallmark of esophageal disease? What are 4 other signs?
regurgitation
- ptyalism
- repeated or painful swallowing
- failure to thrive - thin, emaciated
- coughing or dyspnea due to aspiration pneumonia
What are the 3 major characteristics of regurgitation that differentiate it from vomiting?
- passive - vomiting is a more coordinated, active effort with abdominal contractions
- no bile - presence of bile = vomit
- induced by changes in position
What are the 3 major characteristics of vomiting that differentiate it from regurgitation?
- contains bile
- timing in associated with eating
- active - abdominal contraction, prodromal signs (nausea, lip smacking, drooling)
What are intraluminal and extraluminal causes of esophageal obstruction (choke)?
INTRA - FB, stricture, masses
EXTRA - vascular ring anomaly (PRAA, ligamentum arteriosum constricts esophagus at heart base), mediastinal masses, enlarged LN, cellulitis, abscess
What are the most common foreign bodies seen in dogs and cats?
DOGS - bones, Greenies, sticks, fishhooks, toys
CATS - trichobezoars, toys
What are the 2 major approached for visualizing esophageal foreign bodies?
- thoracic radiographs - start with plain, use contrast to look for strictures or radiolucent FB
- endoscopy - directly visualizes FB within esophagus
How are esophageal foreign bodies treated?
use endoscope to remove or push into stomach to be removed by gastrotomy
What are 4 common consequences of esophageal foreign bodies?
- esophagitis
- esophageal perforation
- stricture
- pneumoia
Stricture:
Esophageal mass:
need ro r/o LN or within esophagus (if only using radiograph)
Mediastinal mass:
extraluminal stricture
What are the 3 most common causes of esophagitis?
- trauma
- chemical injury due to acid reflux - anesthesia, vomiting, GERD
- pill-induced - Doxycycline or Clindamycin pills get stuck and substances that make up the pill cause chemical injury (can compound or give with food)
What 4 treatments are recommended with esophagitis?
- Sucralfate - protects mucosa
- H2 blocker or PPI - reduces acid secretion
- Metoclopramide + Cisapride - tightens LES and promotes gastric emptying (less time in stomach to allow reflux)
- feeding tube placement - consistent and adequate source of nutrition, able to bypass esophagus for healing
What is megaesophagus? What are 3 secondary causes?
persistent diffusely dilated esophagus
- endocrinopathies - hypoadrenocorticism, hypothyroidism
- myopathies or neuropathies - polymyositis, myastenia gravis
- esophagitis
(idiopathic is most common cause!)
What 6 parts of history are especially important in cases of esophageal disease?
- age of onset
- duration of signs
- timining of regurgitation in relation to eating - immediate, delayed (LES)
- contents of regurgitation - tolerance of liquids vs. solids
- known ingestion of FB
- recent anesthesia (regurgitation/vomiting due to anesthesia - healing results in stricture)
A client claims their dog has been vomiting for the last 3 days. She describes:
- vomits food and water in 5 minutes of eating
- cannot hold down food, can hold down a little water
- uncomfortable when swallowing
- no abdominal contractions noted
Is the patient actually vomiting?
no –> regurgitation is a more passive process and timing/ability to hold down some water may indicate a stricture or FB
History of regurgitation, thoracic radiograph:
FB –> looks like a bone!
- removed by endoscopy, severe esophagitis noted –> treated with Sucralfate, PPI, H2 blockers, and PEG tube placement
A 10 y/o MN GSD presents with a 1-month history of regurgitating hours after eating. What differential is at the highest of the list?
megaesophagus or esophagitis –> chronic, delayed, likely affecting lower esophagus
What treatment is recommended for dogs with myasthenia gravis resulting in megaesophagus? What is the most common cause of death?
pyridostigmine + upright feedings (of slurry)
aspiration pneumonia
How are esophageal strictures treated?
balloon dilation –> breaks up scar tissue
- TGH - PPI, metoclopramide, steroids to decrease scar tissue reformation
