Ex 1 - Esophagus Flashcards
Two sphincters of the esophagus
- Cricopharyngeal sphincter/cranial esophageal sphincter
2. Caudal esophageal sphincter
Wall layers of esophagus
- Mucosa: keratinized stratified squamous epithelium
- Submucosa: loose network of fibrous CT w/ varying quantities of sm mm & mucous glands
- Muscularis: striated mm in the dog; terminal 1/3 is striated in the cat
- Adventitia/CT: There is NO outer serial layer in the esophagus
Difference between dogs and cats? (esophagus)
Dogs: all striated muscle
Cats: distal 1/3 is smooth muscle
Clinical signs of esophageal dz (4)
- Regurgitation
- Dysphagia
- Abnormal swallowing
- Gagging, retching
Secondary complications of esophageal dz (4)
- weight loss
- failure to gain weight or grow normally
- chronic or recurrent respiratory problems
- Aspiration pneumonia, tracheitis, nasal discharge
Normal rad appearance - esophagus
Normally can’t see it
Silhouettes (border effacement) w/ adjacent soft tissues in mediastinum
There is occasional fluid accumulation in the caudal thoracic esophagus (usually LRL view)
- creates an oblong region of soft tissue opacity - not to be confused for a mass
***the absence of abnormal esophageal rad findings does NOT R/O esophageal dz –> if CS then consider contrast study
Aerophagia
Very small volume of air in the lumen
- will be transient
- common sites:
1. immediately caudal to the UES
2. thoracic inlet
3. ***dorsal tot he heart base just cranial to the tracheal bifurcation
Effect of general anesthesia - esophagus
May cause marked dilation of a normal esophagus
- mimics megaesophagus, but recovers spontaneously when recovered from anesthesia
Vascular Ring Anomaly
Congenital heart abnormalities (ex. PRAA) –> cause compression (stricture) of the esophagus
*Esophagram can be helpful to determine if there is atony caudal to the stricture
Redundant Esophagus (U-shaped bend)
Incidental finding
Young dogs or brachycephalic breeds - can be problematic
Thoracic rads may be normal or show some gas accumulation near thoracic inlet
Peristalsis is normal
*Contrast may accumulate temporarily in a redundant section and can appear as an out pouching as w/ an esophageal diverticula
Rad signs assoc’d with Megaesophagus
- Tracheal stripe sign
- between luminal gas of the trachea and air w/in the esophagus
- silhouette sign of combined thickness of the tracheal and esophageal walls
- Longus colli mm sign
- esophagus visible caudal to the heart
- the “V” sign on the VD rad
- Food (granular soft tissue/gas mixture can be seen in a dilated esophagus; widened mediastinum; displacing trachea ventrally)
- Secondary findings: Aspiration pneumonia
Which lateral view will show dz in the right middle lung lobe?
LLR
Which view will should dz in the left lung lobes?
RLR???
Pilled cat –> megaesophagus?
Esophageal stricture from esophagitis resulting from pilling cats
Most common VRA
PRAA: esophagus is trapped by the heart, PRAA, main pulmonary artery and ligament arteriosum
- Dilation of the esophagus caudal to the PRAA may indicate concurrent esophageal dysfunction that may persist even when the vascular ring anomaly is corrected
- peanut shape on VD
