Esophagus Flashcards
The esophagus is a muscular tube extending from the _____ to the stomach through the mediastinum. It is usually _____ and not visible on survey radiographs.
pharynx — collapsed
The esophagus is located _____ to the trachea in the cervical region, ____ and ____ to the trachea at the throacic inlet, ____ to the trachea in the thoracic cavity, and continues slightly ____ of midline and _____ of the aorta to the diaphram.
dorsal—-left and ventral—-dorsal — left—-right
The esophagus passes through the ___ ____ of the diaphram to the cardia of the stomach, where it terminates at the ___________ junction. The crainal and caudal aspects are fixed in position, but the middle is quite movable and ______. Two sphincters are present, which are_____ ______ and the caudal _____.
left crus (the aorta passes through the right crus)—-gastroesphageal —distensible—–cranial cricopharyngeal and esophageal.
A slight redundancy is present caudal to the thoracic inlet (exaggerated in brachycephalic breeds), called a __________.
pseudodiverticulum
The caudal esophagus is often visible as a faint, horizontal soft tissue opacity between the ____ and the ___ ____ ____ (commonly seen on the left lateral rad). The esophageal wall is thinnest in the ____ region.
aorta and the caudal vena cava—–thoracic
In dogs, the full length of the esophagus is composed of _____ muscle.
striated
In cats, the proximal portion of the esophagus is striated muscle, but the distal third consists of ______ muscle. In this area, the mucosa forms a series of transverse or oblique lines on a positive contrast study commonly called a “______ _____”
smooth–herringbone pattern
Tracheobronchial LN are located between the ______ and the tracheal _____.
esophagus–bifurcation
Esophageal diverticula is a ___ that extends outward from the esophagus. It may be congenital or acquired. (Uncommon in dogs and cats). Congenital diverticli result from a _______ _____ and weakness of the esophageal wall. Aquired diverticuli are caused by increased ________ _______ or an external adhesion. The esophagal lumen is usually normal size but deviates ______ and _____.
sac—developmental thinning—intraluminal pressure—ventrally and laterally
Congenital diverticuli most often occur in the cranial esphagus, usually near the _____ ____ where they must be differentiated from _____-_____. Lateral radiographs made with the neck extended and then with the neck flexed aid in differentiation: ____-_____ will diminish during extension of the neck.
thoracic inlet— pseudo-diverticuli–pseudo-diverticuli
______ diverticuli are common in the distal esophagus and ______ diverticuli may develop anywhere and often have thickened walls
Pulsion —-traction
Esophageal inflammation (esophagitis) may be localized or generalized. It can be caused from swallowing a ____ FO or from ______ _____ or reflux. Severe chronic inflammation may lead to _____ and _____ of the mucosa. Chronic esophagitis can result in _____, _____, and partial or complete obstruction.
caustic—gastroesophageal regurgitation–errosion and inflammation–scarring, strictures
Contrast radiographs (barium esophagram) of esophagitis may show a thickened _____, mucosal margins are _____. Mucosal ulcerations may appear as barium-filled focal ___-_____ along mucosal boarders. Superficial ulcers may not be detected on rads (best seen on endoscopy). Adherence of barium to esophageal mucosa suggests ____ or _____.
wall—irregular— out-pouchings—errosion or ulceraton
Esophageal FO are usually bones, or objecs with _____ or ______ edges. The perforation of the esophagus results in ______. Esophageal stricture, diverticulum, or fistula is a potential compliction, especially in _______ cases.
irregular or sharp—mediastinitis—–neglected
Clinical signs of esophageal FO include:
regurgitiation, anorexia, dysphagia and ptylalism.
Common sites where most foreign objects lodge are:
Cranial cervical region, thoracic inlet, heart base, and immediately cranial to the diapharam. Metal and mineral opacity objects usually are readily identifed. ST opacity objects may mimic a cervical or mediastinal mass. Small objects must be outlined by gas or contrast medium to be visible.
Iodineated contrast media may be perferred if esophageal _____ is suspected. Barium in mediastinum can cause a severe _______ reaction. However, iodinated agents provide poor _______ detail and are rapidly _____, which may compromise dx.
rupture—-granulomatous—-mucosal —diluted
Complete or severe esophageal obstruction will result in dialation _____ to the lesion. Incomplete obstructions present with a ____ ____ at the site of the FO. Esophagrams may document a ____ or a _____ (esophagobronchial, esophago-tracheal.
proximal—filling defect—leak or fistula
DDF for esophageal FO:
Espohageal mass (tumor, abscess, granuloma)
Hiatal hernia
Normal swallowing (transient conditon)
Position abnormalities of the esophagus:
- Mediastinal shift (pneumothorax, atelectasis0
- hernia (diaphragmatic, hiatal)
- djacent mass
- Conditions that mimic esophageal displacement (rotation positioning- mediastinum follows sterunm)
Esophageal neoplasias are uncommon in the dog and cat. Granulomas from _____ ____ can transform into fibrosarcoma or osteosarcoma. Clinical signs of neoplasia include progressive _____, dysphagia, weight loss and anorexia. Dx is made with ____ AND ____.
Spirocerca lupi—regurgitation—-endoscopy and biopsy
Gastroesophageal intussusception are invagination of the _____ into the esophagus. It usually results in seophageal obstruction and an _______ situation. (GSD is overrepresented)
Stomach- (may or may not be accompanied by other abdominal organs (duodenum, spleen, pancreas, omentum)
Emergency
Most often in young dogs (<1yr), males more common than females
Clinical signs of gastroesophageal intussusception include:
persistent regurgitation which may progress to hypovolemic shock and death
Endoscopy can make or confirm the dx and aid in ruling out other esophageal masses such as FO, tumor, abscess or ganuloma
Gastroesophageal intussusceptions may be ______ and difficult to see on radiographs. You may see a well-defined, homogeneouus or heterogenous soft tissue mass in the _____ mediastinum. The esophagus is _____ crainal to the lesion. The ____ ____ may not be visible or in a abnormal shape. Rugal folds may be visible in intussusecption portion if ____ ____ gas is present. Spleen may not be ______.
transient—caudal—-dialated (usually with gas)–gastric fundus—-sufficient luminal–identified
Megaesophagus is an _____ _____ of the esophagus due to a motility disoder. It is the MOST COMMON cause of regurgitation in dogs and cats (it must be differentiated from vomiting)
abnormal dialation
Congenital megaesophagus becomes evident at _____ where as aquired megaesophagus develops in ____-____ dogs b/t ___-___years. Clinical signs are regurgitation, weight loss (with a normal or decreaseed appetite), cough, fever (secondary to ____ ____) and nasal discharge (secondary to _____)
weaning—–middle aged (7-15 yrs) —aspiration pneumonia—rhinitis
Associated functional disorders with megaesophagus;
_______ (nonopening or inappropriate opening)
______ is a failure to close (resulting in megaesophagus.
______ is a muscular dysfunction at the cardia of the stomach which may be accopmanied by megaesophagus
Achalasia
Chaalasia
Cardiospasm
Radiographic findings with megaesophagus are that the appearance of the esophagus depends on the ____ of contents, _____ of condition and ___ and size of animal.
volume
duration
age
Entire thoracic ewophagus and variale portions of cervical are abnormally distended with ___, ___, or/and ____. NO narrowing is evident (different from vascular ring anomaly and strictures).
air
fluid
ingesta
Congenital malformations of the aortic arches can entrap the esophagus call ____ ___ _____. The esophagus is usually compressed between the aorta and ______, resulting in functional stenosis. It is more common in dogs than cats
Vascular Ring Anomalies
treacha
Dogs that are predisposed are (4). The most common sign is regutgitation of ____ _____ shortly after weaning. _____ ____ is a frequent complication.
Great Danes, GSD, Irish Setter, Boston Terrier
solid food
Aspiration pneumonia.
Radiographic findings with vascular ring anomalies can cause the esophagus cranial to heart base is _____. The trachea is displaced ____ and to the _____. The cardiac sihouette is normal in size and shape, but the base of the heart may be displaced _____. Crainal mediastinum may be widened and increased in ____.
dialted
ventrally right
ventrally
opacity
Narrowing typically occurs near the ____ intercostal space or near the ____ of the heart. Contrast medium may or may not fill the esophagus ____ to the lesion, depending on the severity of the stricture. DDF for VRA are generalized ____________, esophageal _____ near the base of the heart (trauma, chemical irritant, tumor), FO
4th
base
distal
megaesophagus, stricture
Reasons for decreased opacity in the esophagus:
- Gas - swallowed air, aeorphagia (due to struggling or excitement- usually in GI tract too), dialation associated with anesthesia/sedation (may mimic megaesophagus)
- Gas adjacent to esophagus- pneumomediastinum (ruptured esophagus to trachea), pneumothorax, hyperinflated lungs, superimosition artifact (subcutaneous emphysema)
Reasons for increased opacity (homogenous or heterogenous, lateral or general):
- Megaesophagus
- vascular ring anomaly (crainal to heart base)
- Stricture
- Inflammation- GI regurg or reflux, infection, passage of FO or irritant)
- Mass- abscess, primary esophageal tumor, SCC, Osteosarcoma or fibrosarcoma secondary to Spiocerca lupi, Leiomyoma, Adenocarcinoma)
- Secondary esophageal tumor (rare): Bronchogenic adenocarcinoma, gastric carcinoma, etc.)
- Esophageal diverticulum
- hiatal hernia
Reasons for abnormal narrowing of esophagus:
- Compression by adjacent mass- thyroid tumor (carcinoma), lymphadenopathy, Heart base tumor, abscess/granloma
- Vascular Ring anomaly (narrowing near heart base)
- Mural and intraluminal lesions
- Severe or chronic inflammation
- FO
- Trauma, neoplasia
Abnormal dialation of esophagus:
- Anesthesia/heavy sedation
- severe dyspnea and aerophagia
- Congenital Megae
- Aquired Megae- metabolic dz (hypoadrenocorticism, hypothyroidism, DM, Hyperinsulinism (insulinoma), uremia)
- Immune- mediated- polyneuritis, polymyositis, systmeic lupus erythematosus, Thymoma
- Toxins; heavy metal poisoning (lead, zinc, cadmium, thallim), Organophosphates, Cholorinated hydrocarbons, herbicides, botulism, snake venom, tetanus
