Chapter 29: Esophagus Flashcards
Layers of the esophagus
Mucosa (squamous epithelium), submucosa, and muscular propria (longitudinal muscle layer); no serosa
Does the esophagus have serosa?
No
Muscle: upper 1/3 esophagus
Striated muscle
Muscle: middle 1/3 and lower 1/3 esophagus
Smooth muscle
Major blood supply to the thoracic esophaugs
Vessels directly off the aorta are the major blood supply to the thoracic esophagus
Artery: cervical esophagus
Supplied by the inferior thyroid artery
Artery: abdominal esophagus
Supplied by left gastric and inferior phrenic arteries
Venous drainage of the esophagus
Hema-Azygous and azygous veins in chest
Lymphatics of esophagus
Upper 2/3 drains cephalad, lower 1/3 caudad
Travels on posterior portion of stomach as it exits chest; becomes celiac plexus
Right vagus nerve
Right vagus nerve: can cause persistently high acid levels postoperatively if left undivided after vagotomy
Criminal nerve of Grassi
Travels on the anterior portion of stomach; goes to liver and biliary tree
Left vagus nerve
Travels from right to left at T4-5 as it ascends mediastinum; inserts into left subclavian vein
Thoracic duct
Where is the upper esophageal sphincter in relation to the incisors?
UES is 15cm from incisors
Is the cricopharyngeus muscle (circular muscle, prevents air swallowing); recurrent laryngeal nerve innervation
Upper esophageal sphincter (UES)
Normal UES pressure at rest
60 mmHg
Normal UES pressure with food bolus
15 mmHg
Most common site of esophageal perforation (usually occurs with EGD)
Cricopharyngeus muscle
What causes aspiration with brainstem stroke?
Failure of cricopharyngeus to relax
Where is lower esophageal sphincter in relation to incisors?
LES is 40 cm from incisors
Relaxation mediated by inhibitory neurons; normally contracted at resting state (prevents reflux); is an anatomic zone of high pressure, not an anatomic sphincter
Lower esophageal sphincter (LES)
Normal LES pressure at rest
15 mmHg
Normal LES pressure with food bolus
0 mmHg
Anatomic areas of esophageal narrowing
- Cricopharyngeus muscle
- Compression by the left mainstem bronchus and aortic arch
- Diaphragm
Swallowing stages
- Primary peristalsis: occurs with food bolus and swallow initiation
- Secondary peristalsis: occurs with incomplete emptying and esophageal distention; propagating waves
- Tertiary peristalsis: non-propagating, non-peristalsing (dysfunctional)
What initiates swallowing stages?
CNS initiates swallow
Normally contracted between meals
UES and LES
Swallowing mechanism
Soft palate occludes nasopharynx.
Larynx rises and airway opening is blocked by epiglottis.
Cricopharyngeus relaxes.
Pharyngeal contraction moves food into esophagus.
What relaxes soon after initiation of swallow?
LES - vagus mediated.
Surgical approach:
- Cervical esophagus
- Upper 2/3 thoracic
- Lower 1/3 thoracic
- Cervical: left
- Upper 2/3: right (avoids the aorta)
- Lower 1/3 thoracic: left (left-sided course in this region)
Causes hiccoughs
Gastric distention, temperature changes, ETOH, tobacco
Hiccough reflex arc
Vagus, phrenic, sympathetic chain T6-T12
Primary esophageal dysfunction
Achalasia, diffuse esophageal spasm, nutcracker esophagus
Secondary esophageal dysfunction
GERD (most common), scleroderma
Best test for heartburn (can visualize esophagitis)
Endoscopy
Best test for dysphagia or odynophagia (better at picking up masses)
Barium swallow
Dx / Tx: meat impaction
Endoscopy
- Trouble in transferring food from mouth to esophagus
- Liquids worse than solids
Pharyngoesophageal disorders
What are pharyngoesophageal disorders most likely secondary to?
Most commonly neuromuscular disease - myasthenia gravis, muscular dystrophy, stroke
Can have upper esophageal web, iron deficiency anemia
- Tx: dilation, iron, need to screen for oral cancer
Plummer-Vinson syndrome
Caused by increased pressure during swallowing
Zenker’s diverticulum
What type of diverticulum is Zenker’s?
Is a false diverticulum located posteriorly.
Where does Zenker’s diverticulum occur?
Occurs between the pharyngeal constrictors and cricopharyngeus
What causes Zenker’s diverticulum?
Caused by failure of the cricopharyngeus to relax
Symptoms: upper esophageal dysphagia, choking, halitosis
Zenker’s diverticulum
Dx: Zenker’s diverticulum
Barium swallow studies, manometry; risk for perforation with EGD and Zenker’s
Tx: Zenker’s diverticulum
Cricopharyngeal myotomy (key point); Zenker’s itself can either be resected or suspended (removal of diverticula is not necessary)
Post op management of Zenker’s diverticulum
Left cervical incision, leave drains in, esophagogram POD#1.
- Is a true diverticulum - usually lies lateral
- Due to inflammation, granulomatous disease, tumor.
- Usually found in the mid-esophagus
- Symptoms: regurgitation of undigested food, dysphagia
Traction diverticulum
Tx: traction diverticulum
Excision and primary closure if symptomatic, may need palliative therapy (i.e. XRT) if due to invasive CA; if asymptomatic, leave alone
- Rare, associated with esophageal motility disorders (e.g., achalasia)
- Most common in the distal 10 cm of the esophagus
- Most are asymptomatic; can have dysphagia and regurgitation
Epiphrenic diverticulum
Dx / Tx: epiphrenic diverticulum
Dx: esophagram and esophageal manometry
Tx: diverticulectomy and esophageal myotomy on the side opposite the diverticulectomy if symptomatic
Where are epiphrenic diverticulum most common?
Most common in the distal 10 cm of the esophagus
- Dysphagia, regurgitation, weight loss, respiratory symptoms
- Caused by lack of peristalsis and failure of LES to relax after food bolus
- Secondary to neuronal degeneration in muscle wall
Achalasia
What will manometry show in achalasia?
Increased LES pressure, incomplete LES relaxation, no peristalsis
Can get tortuous dilated esophagus and epiphrenic diverticula; bird’s beak appearance
Achalasia
Initial Medical Treatment: achalasia
Balloon dilatation of LES -> effective in 80%; nitrates, calcium channel blocker
Treatment for achalasia when medical treatment and dilation fail
Heller myotomy (left thoractomy, myotome of lower esophagus only; also need partial Nissen fundoplication
Organism producing similar symptoms as achalasia
T. cruzi
Chest pain, may have dysphagia; may have psychiatric history
Diffuse esophageal spasm
Manometry in diffuse esophageal spasm
Frequent strong non-peristaltic unorganized contractions, LES relaxes normally
Treatment: diffuse esophageal spasm
Calcium channel blocker, nitrates; Heller myotomy if those fail (myotomy of upper and lower esophagus)
What is a Heller myotomy?
procedure in which muscles of the cardia are cut (lower esophageal sphincter)