Sabiston Esophagus Flashcards
Esophagus Coarse
-The cervical esophagus begins as a midline deviates slightly to the left of the trachea as it passes through the neck into the thoracic inlet
-At the level of the carina, it deviates to the right to accommodate the arch of the aorta.
-It then winds its way back under the left mainstem bronchus and remains slightly deviated to the left
Killian triangle
-The inferior pharyngeal constrictor muscle is composed of two consecutive muscle beds—the thyropharyngeus and cricopharyngeus muscles—
-The transition between the oblique fibers of the thyropharyngeus muscle and the horizontal fibers of the cricopharyngeus muscle creates a point of potential weakness
The circular muscles are an extension of the
cricopharyngeus muscle
Then they become the middle circular muscles of the lesser curvature of the stomach
The collar of Helvetius
the transition of the circular muscles of the esophagus to oblique muscles of the stomach at the incisura (cardiac notch)
Three distinct areas of narrowing that contribute to its shape.
1-cricopharyngeus muscle is the narrowest point of the gastrointestinal tract
2-bronchoaortic constriction at the level of the fourth thoracic vertebra
3-the diaphragmatic constriction
The UES corresponds reliably to the
to the cricopharyngeus muscle
There are two anatomic considerations that may be used to identify the GEJ
1-The squamocolumnar epithelial junction (Z-line)
2-The transition from the smooth esophageal lining to the rugal folds of the stomach may also identify the GEJ
Externally
1-the collar of Helvetius (or loop of Willis), where the circular muscular fibers of the esophagus join the oblique fibers of the stomach
2-the gastroesophageal fat pad
Blood Supply to Esophagus
-The cervical esophagus > inferior thyroid arteries > branch off of the thyrocervical trunk on the left and the subclavian artery on the right
-The cricopharyngeus muscle, marks the inlet of the esophagus > superior thyroid artery.
-The thoracic esophagus four to six esophageal arteries coming off the aorta + branches off the right and left bronchial arteries + descending branches off the inferior thyroid arteries, intercostal arteries, and ascending branches of the paired inferior phrenic arteries.
-The abdominal esophagus > the left gastric artery and paired inferior phrenic arteries.
Venous Drainage of Esophagus
-submucosal venous plexus is the first basin for venous drainage
-cervical esophagus > the submucosal venous plexus drains into the inferior thyroid veins
-The thoracic esophagus > submucosal venous plexus joins with the more superficial esophageal venous plexus and the venae comitantes > drains into the azygos(RT) and hemiazygos(LT) veins
-The intercostal veins > drain into the azygos venous system.
-The abdominal esophagus > systemic and portal venous systems through the left and right phrenic veins and left gastric (coronary) vein and short gastric veins
The superior laryngeal nerve
external : motor innervation to the inferior pharyngeal constrictor muscle and cricothyroid muscle
internal : sensory innervation to the larynx
recurrent laryngeal nerves
right : loop underneath the right subclavian
left : loop underneath the aortic arch
then travel upward in the tracheoesophageal groove to enter the larynx laterally underneath the inferior pharyngeal constrictor muscle.
innervate the cervical esophagus, including the cricopharyngeus muscle
three types of esophageal contractions
-Primary peristaltic contractions : progressive and move down the esophagus at a rate of 2 to 4 cm/sec
-Secondary : also progressive but are generated from distention or irritation of the esophagus rather than voluntary swallowing.
-Tertiary contractions : nonprogressive, nonperistaltic, monophasic or multiphasic
esophageal motility disorders have been classified into primary and secondary causes
Primary : achalasia, diffuse esophageal spasm (DES), nutcracker (jackhammer) esophagus, hypertensive LES, and ineffective esophageal motility (IEM).
Secondary : from progressive damage induced by an underlying collagen vascular or neuromuscular disorder;
scleroderma, dermatomyositis, polymyositis, lupus erythematosus, Chagas disease, and myasthenia gravis
Diffuse(Distal) Esophageal Spasm
-Manifested in a similar fashion to achalasia
-Motor abnormality of the esophageal body
- Muscular hypertrophy and degeneration of the branches of the vagus nerve
-Contractions are repetitive, simultaneous, and of high amplitude.
- Regurgitation of esophageal contents and saliva is common
-acid reflux can aggravate the symptoms.
-gallstones, peptic ulcer disease, and pancreatitis, all trigger DES
-corkscrew esophagus or pseudodiverticulosis on an esophagram
-A distal bird beak narrowing of the esophagus
Nutcracker Esophagus
-characterized by excessive contractility
-is the most common of all esophageal hypermotility disorders
-most painful of all esophageal motility disorders.
-An esophagram may or may not reveal any abnormalities
EGJ outflow obstruction (Hypertensive Lower Esophageal Sphincter)
-evidence of effective peristalsis that is not present in achalasia
-diagnosis by manometry with a hypertensive, poorly relaxing sphincter
-esophagram may show narrowing at the GEJ with delayed emptying and abnormalities of esophageal contraction
progressive Achalasia leads to
aspiration
Pneumonia
lung abscess
bronchiectasis
Achalasia is also known to be a premalignant condition
Squamous cell carcinoma (SCC) is the most common type
Feature of Achalasia on Esophagogram or xray
-Lack of a gastric air bubble is a common finding
advanced stage of disease > massive esophageal dilatation, tortuosity, and sigmoidal esophagus (megaesophagus)
Esophagectomy is considered in Achalasia
in any symptomatic patient with a tortuous dilated esophagus (megaesophagus)
sigmoid esophagus
failure of more than one myotomy
or reflux stricture that is not amenable to dilatation
megaesophagus Sx
total esophagectomy incorporating a transthoracic dissection may be safest
Use of POEM
may obviate the need for esophagectomy in this malnourished, often high-risk, patient population.
Diverticular Disorders
The three most common sites of occurrence are
pharyngoesophageal (Zenker)
parabronchial (midesophageal)
epiphrenic (supradiaphragmatic)
false pulsion diverticula
Zenker diverticulum and an epiphrenic diverticulum
endoscopic findings
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