Esophageal Motility Disorders

1. Embryology
Muscular epithelial-lined tube
Derived from primitive foregut
Second week of embryologic development
Mesoderm forms and separates ectoderm from endoderm--providesmaterial necessary for connective tissue, muscular coats, serous coverings
2. Histology and Final Development
Adventitia: outer loose connective tissue containing nerves, lymphatics, blood vessels
Muscularis: two layers of muscle--outer longitudinal and an inner circular
Submucosa: connects muscularis with the mucosa--strongest layer--elastic tissue; collagenous fibers; network of vessels & nerves
Mucosa: squamous, columnar; Z-line
3. Vascularity
Arterial: 3 sources
1. Inferior and superior thyroid arteries: cervical esophagus
2. Tracheobronchial, aortic arch and esophageal branches: body of esophagus
3. Left gastric and splenic arteries: GEJ
Veins: drainage pattern similar to lymphatics
Submucosal plexus--communicating veins--perforating veins that pierce the muscularis
Eventually drain into inferior thyroid, azygous, hemiazygous,left gastric, splenic, left gastroepiploic systems
4. Lymphatics:
Submucosal lymphatics form long channels that run parallel to esophageal axis
May travel long distances before draining into regional nodes
5. Innervation
Nerves: extraesophageal
Sympathetic: cervical, thoracic chains; celiac plexus and ganglia
Parasympathetic: vagus nerve muscular plexus around the circular layer of the muscularis (Auerbach's plexus)
Submucosal plexus (Meissner's plexus)
Auerbach's and Meissner's plexus are interconnected and are responsible for the fine- control mechanism of esophageal function
6. Nerves: central
Nucleus ambiguous
Dorsal motor nucleus of Vagus through the myenteric plexus
Both work together on the longitudinal and circular muscles to propel a bolus--peristalsis
7. Peristalsis
Primary: normal propulsive wave in response to the stimulation of normal voluntary deglutition
Secondary: normal wave without voluntary deglutition: best defense
Tertiary: abnormal; may occur spontaneously or following deglutition
8. Normal function
Upper Esophageal Sphincter (UES)
Level of cricoid cartilage C 5-6
Composed of cricopharyngeus and inferior pharyngeal constrictors
Remains contracted between swallows due to continuous stimulation by IX and XI
Resting tone: 45 - 65 mmHg (range 32 -101 mmHg)
Swallow: inhibition of all motor nerve stimulation; UES opens; closes; rebound; baseline pressures
9. Esophageal Body
Proximal striated muscle: direct innervation to its motor end plate from nucleus ambiguous
Smooth muscle: indirect neural input from dorsal motor nucleus (X) via myenteric plexus
Innervation: longitudinal muscle shortens; circular muscle contracts; peristalsis
Duration and amplitude: weaker in proximal esophagus; stronger, longer in distal esophagus
10. Lower esophageal sphincter (LES)
Specialized muscle arrangement 3 - 4 cm above gastroesophageal junction (GEJ)
High pressure zone with resting tone 15 - 25 mmHg (24.8 mmHg)
Influenced by neural and hormonal factors; drugs
Relaxes at time of swallowing; closes with passage of contraction through sphincterManometry
11. Diagnostic Techniques
Radiology
Endoscopy
Reflux Disease
Esophageal Malignancies
Esophageal Biopsies
Motility Studies
24 Hour pH Monitoring
Acid Perfusion Tests (Bernstein's Test)
Radionuclide Emptying Studies
12. Oropharyngeal Dysphagia
Neurologic: central vs peripheral
Myogenic
Cricopharyngeal Muscle Dysfunction
Iatrogenic
Lower esophageal disease
13. Idiopathic Motor Disorders
Hypomotility Disorders
Achalasia
Hypermotility Disorders
Diffuse Esophageal Spasm
Hyperperistalsis (Nutcracker; Supersqueeze)
Hypertensive LES
Nonspecific Esophageal Motility Disorders
14. Achalasia
Young adults -- 1 in 100,000 -- Cause unknown
Loss of control at the postganglionic, nonadrenergic and noncholinergic inhibitory nerves -- LES dysfunction and esophageal body changes
? denervation; Chagas' Disease
Compounded by physical & psychologic stress
LES: normal or increased resting pressure
Incomplete or absent relaxation
15. Symptoms: dysphagia; odynophagia; regurgitation; aspiration and its complications; made worse by cold liquids and stressful situations
Squamous cell carcinoma 1-10%
Peristalsis absent in esophageal body; high resting pressure
Contractions weak at all recording levels
Esophageal dilatation; megaesophagus
Barium swallow: "bird's beak" esophagus
16. CXR: widened mediastinum; air-fluid level in posterior mediastinum; absence of gastric bubble
Endoscopy: changes vary with stage
Normal
Food/fluid retention in fasting state
Thickened mucosa with wide folds
Hyperemia: stasis esophagitisAchalasia Upper GIAchalasia Manometry
17. Treatment
Medication: calcium channel blockers--decrease LES resting pressures--improves symptoms, not emptying
Early disease with minimal symptoms
Dilatation: stretches/ruptures fibers of the LES
Lowers LES resting pressure; improves emptying
Good to excellent short term results in 65% of patients
Esophageal rupture seen in 4%
Reflux seen in 7 - 17%
18. Esophageal myotomy: improves obstructive symptoms more effectively than dilatation
Can be done via left thoracotomy, laparotomy, or scope
5 - 7 cm myotomy on distal esophagus
Extends 1 cm onto gastric wall
Mucosa dissected from muscularis
90% relief of dysphagia short and long term
? concomitant antireflux procedure: partial fundoplication
19. Diffuse Esophageal Spasm
Rare--cause is unknown; muscle hypertrophy; degenerative changes in Vagus branches
Symptoms: odynophagia, dysphagia, unexplained chest pain
Anxious individuals
Symptoms worsened by stress
Must differentiate from CAD
20. Simultaneous segmental contractions on x-ray
Corkscrew / rosary bead esophagus
Diverticulum: intermittent or epiphrenic
Endoscopy: usually normal
Peristalsis:>30% repetitive tertiary contractions
Duration and amplitude occasionally abnormal
LES: occas. hypertensive; occas. incomplete relaxation Spasm Upper GISpasm Manometry
21. Treatment
Nitroglycerin
Calcium channel blockers: decreases amplitude of contraction & reduces LES pressure
Control anxiety and precipitating factors
Esophageal myotomy: results not as good as in achalasia; good to excellent results in 67 - 70%
If LES is transected must do a partial fundoplication
Dilatation if hypertensive LES is documented
22. Nutcracker or Supersqueeze Esophagus
Normal peristalsis
Contraction amplitude is > 2 standard deviations above normal > 180 mmHg in distal esophagus
Duration of contractions >6 sec.
LES: occas. hypertensive; usually normal
Primary symptoms is chest pain
Strong emotional influence / hypochondriacal Nutcracker Esophagus Manometry
23. Treatment
Psychologic assessment and support
Calcium channel blockers
Dilatation or myotomy are of little or no benefit
Hypertensive LES
Resting pressure > 45 mmHg; normal relaxation and peristalsis
Conservative medical / psychiatric management
24. Idiopathic Gastroesophageal Reflux
Peristalsis and contraction amplitude are normal
LES is weak (gradient < 6 mmHg) allowing gastric acid to reflux and bathe the lining of the lower esophagus--responsible for 60 - 70 % of all GERD
Sphincter failure
Primary muscle dysfunction
25. Increased exposure to acid further weakens the LES leading to further reflux and mucosal damage
Esophageal contraction abnormalities with poor amplitude and aperistalsis
Correlation between the severity of sphincter hypotension and extent of functional abnormalities in the esophageal body
(DeMeester)
? correction cures abnormalities
26. Reflux Disease and Scleroderma
Seen in 90% of patients with scleroderma
Atrophy of smooth muscle components
Fibrous infiltration
Incompetence of LES with disappearance of propulsive and emptying mechanisms
Antireflux procedures not as successful though some improvement is seen Reflux
27. Idiopathic Gastroesophageal Reflux
Frequent association with Type I hiatal hernia
Alterations in the anatomy of the hiatus
Phrenoesophageal membrane
Secondary causes
Delay of gastric emptying
Pyloric stenosis
Gastric mass
Poor esophageal wall muscle tone (scleroderma)
28. Reflux: two factors must occur
Acid-peptic or pancreaticobiliary secretions must reach the esophagus with increased frequency
Esophagus must be unable to clear those refluxed materials back into the stomach
Treatment
Medical treatment
Surgical treatment if medical treatment fails
29. Diagnosis
Barium swallow
Fiberoptic / rigid endoscopy
Multiple biopsies if findings consistent with severe esophagitis, stricture, Barrett's epithelium, ulceration
Esophageal function test (manometry, acid reflux, perfusion and clearing tests, 24 hr pH monitoring)
30. Indications for surgery
Symptomatic after 3 months of medical therapy
Persistent esophagitis, stricture, aspiration, bleeding
Positive 24 hr pH study
Manometry suggesting dysfunctional LES and adequate esophageal motility(peak amplitude > 30 mmHg)
Barrett's mucosa if biopsies are benign (no CIS)
31. Operation of choice
Restoration of the anatomic and physiologic relationships of the LES at the GEJ
360 degree wrap (normal esophageal motility)
270 degree wrap (dysfunctional esophagus)
Esophageal resection (rare)
Totally unyielding (fibrotic) esophagus
Barrett's esophagus with CIS or frank malignancy
Gastroplasty: falling out of favor
Procedures
Nissen Fundoplication
Belsey Mark IV
Hill Fundoplication
Collis Gastroplasty
Collis-Belsey Procedure
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EXTENDED OUTLINEAnatomy and functional evaluation
1. Anatomy
a) Begins (transition from pharynx to esophagus) at lower end of sixth cervical vertebra/cricoid cartilage
b) Ends (transition to stomach) at 11th thoracic vertebra
c) Esophagus is midline, passing to the left in lower neck and upper thorax, then back to midline, then to left again in lower thorax to pass through diaphragmatic hiatus
d) Follows curve of vertebral column except to pass anteriorly to pass through diaphragmatic hiatus
e) Sites of perforation during rigid esophagoscopy:
i) Cricopharyngeus
ii) Terminal left anterior deviation
f) Measurements
i) Incisors to cardia = 38-40cm (men), 36-38 (women)
ii) Cricopharyngeus to cardia =23-30cm, avg. 25
iii) Incisors to cricopharyngeus = 14-15cm
iv) Incisors to tracheal bifurcation/indentation of aortic arch = 24-26cm
g) Anatomic relations of esophagus
i) Trachea and cervical spine
ii) Recurrent laryngeal nerves - in tracheoesophageal groove - left is closer to esophagus
iii) Above tracheal bifurcation, esophagus passes to the right of the aorta
iv) From arch down, esophagus lies to the right of the aorta
v) 8th vertebra - left wall of esophagus is covered only by mediastinal pleura - common site of perforation in Boerhaave’s syndrome
vi) Passing through diaphragmatic hiatus, phrenoesophageal membrane surrounds
vii) 2cm of abdominal esophagus between membrane and cardia - subjected to positive pressure
viii) Thoracic duct - through diaphragm behind aorta - in thorax, dorsal to esophagus, from 5th thoracic vertebra up, it passes to left, then departs from esophagus in neck to join L SCV at junction of IJV
h) Musculature of the esophagus
i) Opening is collared by cricopharyngeus muscle
ii) Outer longitudinal layer and inner circular layer
iii) Circular muscle is elliptical
iv) Upper esophagus is only striated muscle
v) At upper/middle 1/3 junction - 50% smooth muscle
i) Arterial supply of the esophagus
i) Cervical = inferior thyroid artery (mainly) + common carotid, SCA
ii) Thoracic = bronchial arteries (75% have one R and 1-2 L)
iii) Abdominal = branches of left gastric and inferior phrenic arteries
iv) After penetrating esophagus, arteries branch in T to form longitudinal anastomoses
v) Esophagus can be mobilized from stomach to aortic arch w/o devascularization
j) Venous drainage
i) Cervical = inferior thyroid
ii) Thoracic = bronchial, azygos and hemiazygous veins
iii) Abdominal = cardiac vein
k) Innervation
i) Parasympathetic = vagus
ii) Cricopharyngeus and cervical esophagus - recurrent laryngeal nerves
iii) RLN injury causes vocal cord paralysis and dysfunction of cricopharyngeus and of cervical esophageal motility, predisposing to aspiration
iv) Esophageal plexus receives fibers from vagus and from thoracic sympathetic chain
l) Lymphatic drainage
i) Submucosal plexus - lymph flow is longitudinal - extensive submucosal spread (of tumor) can occur
2. Normal structure and function
a) Pharyngeal phase of swallowing
i) Tongue is piston - propels food bolus as soft palate is closed
ii) Swallowing is reflex, once initiated
iii) Larynx is elevated and epiglottis covers opening of larynx
iv) Pharyngeal pressure increases to 45mm Hg
v) Food propelled by pressure gradient into thoracic esophagus
vi) Upper, striated portion of esophagus relaxes, then contracts within 0.5 seconds to twice its resting level of 30mm Hg
vii) A peristaltic wave of 30mm Hg begins in the esophagus
viii) Afferent nerves of pharynx are glossopharyngeal and superior laryngeal branch of vagus
ix) Efferent nerves arise from CN V, VII, X, XI, XII and C1-3
x) Motor disorders of pharyngeal swallowing:
a) Incomplete upper sphincter relaxation
b) Loss of skeletal portion of cervical esophagus
b) Esophageal phase of swallowing
i) Pressure gradient of -6mm Hg in thoracic esophagus to +6mm Hg intraabdominal
ii) Lower 1/3 of esophagus is most important
a) Peristaltic wave of 30-120 mm Hg
b) Rises to a peak in 1 sec, lasts 0.5 sec, then subsides in 1.5 sec
c) Wave moves down the esophagus at 2-4 cm/sec, reaches distal esophagus 9 sec after swallow starts
d) Vagal modulated wave
e) If vagi are preserved, muscle can be divided and propagate wave
f) Vagal fibers end in myenteric plexus
g) No known sympathetic innervation of the esophagus
iii) Pathologic states
a) Diffuse esophageal spasm - simutaneous contraction
b) Achalasia - failure of LES relaxation
c) Scleroderma - loss of contraction of smooth muscle portion of esophagus
3. The antireflux mechanism
a) LES
i) No distinct anatomic sphincter, but muscular architecture of cardia acts like a sphincter
ii) Gastric contraction results in increased LES pressure
b) Resting LES pressure
i) Correlates with incidence of GERD
ii) Truncal vagotomy has no effect
iii) Atropine (and other anti-cholinergics) reduces LES tone but does not cause GER
iv) In pharmacologic doses:
a) Secretin, cholecystokinin, glucagon, prostaglandins reduce LES pressure
b) Gastrin, bombesin, motilin augment it
v) Low LES tone in GERD is probably due to abnormal myogenic function
vi) Results of antireflux operations are independent of changes in resting LES pressure
vii) Myotomy can be performed along the length of the LES without resulting in reflux
c) Phrenoesophageal ligament
d) Intra-abdominal esophagus
i) Laplace’s law - pressure required to distend a soft tube is inversely proportional to its diameter
ii) Small-diameter esophagus requires high intragastric pressure to allow reflux
iii) LES competence directly proportional to length of intra-abdominal esophagus in cadaver studies by DeMester
4. GERD
a) Results from decrease in LES pressure, shortening of the intra-abdominal esophagus or both
b) Competence of cardia
i) Requires adequate LES pressure + intrabdominal length
ii) 80% prob of GERD when LES <5mmHG (independent of length)
iii) 80% prob of GERD when length <1cm (independent of pressure)
iv) Low incidence when pressure > 20mmHg and >2cm abd length
c) Gastric function
i) Delayed gastric emptying
ii) ­ intragastric pressure and distention shorten intraabdominal length
d) Overall LES length is also a factor in GERD
e) Esophageal clearance
i) Gravity, salivation and swallowing
ii) Pts w/complications of GERD (Barrett’s and stricture) have higher proportion of weak amplitude and simultaneous contractions
iii) ­ frequency of swallows (0.87à 2.59/min) during episodes of reflux
iv) Any impairment of motility may ­ exposure time
f) LES relaxation-abnormal will à increased exposure
g) Hiatal hernia
i) Phrenoesophageal ligament and snug hiatus prevent distention of abdominal esophagus
h) Antirreflux operations restore to normal the failed components of a mechanically defective sphincter
5. Objective assessment of esophagus
a) Esophageal and upper GI barium studies
i) ­ accuracy with video/cine
ii) ­ accuracy with solid and liquid boluses
iii) Intraluminal abnormalities, landmarks
iv) Some motor dysfunction - spastic contractions
v) Mucosal lesions better seen with double contrast
vi) GERD- reflux only seen in 40% of those with manometry proven
b) Esophagoscopy
i) Any patient who reports dysphagia
ii) Confirm structural abnormalities w/bx
iii) Hiatal hernia = a pouch lined with gastric rugal folds lying 2cm above crural indentation (identify w/a sniff)
iv) Esophagitis
a) Grade I= reddening w/o ulceration
b) Grade II= erosive and invasive, not circumferential
c) Grade III= confluence of erosions (cobblestone) - no stricturing
d) Grade IV= complications
v) Stricture
a) Multiple biopsies
b) Dilate
vi) Barrett’s
a) Difficulty visualizing squamo columnar jxn
b) Mucosa is red, more luxuriant
c) Biopsy proximal to lesion to determine junction w/nl squamous mucosa
d) Surveillance = 4 circumferential biopsies a t 2cm intervals
vii) Submucosal lesions - do not biopsy
c) The acid perfusion test
i) 0.1N HCl or H2O infused 15 cm above LES
ii) Pt reports symptoms
iii) Positive test is pt reporting symptoms w/acid relieved by saline
iv) Reduced sensitivity in pts w/stricture or Barrett’s
d) Manometry
i) Indications
a) Motor abnormality of esophagus suspected
b) Dysphagia or odynophagia w/o definite structural abnormality on Ba swallow
c) Confirm dx of achalasia, esophageal spasm, scleroderma
d) GERD - assess esophageal clearance prior to surgery
e) Determine LES pressure, total and intra abdominal length
ii) Pressure-measuring catheter is withdrawn rapidly or stepwise across cardia
iii) Measurements
a) Relaxation of LES to gastric levels during swallow
b) Respiratory inversion point - reference point for LES
c) Response to 10 pharyngeal swallows-wet swallows are more sensitive
iv) Achalasia (Fig 39-21)
a) LES does not fully relax
b) All waves in body are simultaneous
c) No primary peristaltic waves are seen
d) Resting pressure of body is usually elevated
v) Scleroderma (Fig 39-22)
a) All muscular function of distal esophagus is obliterated
b) No high pressure zone
c) No contractions in body (lower 2/3 of esophagus)
vi) Simultaneous, repetitive or broad-based powerful contractions
a) Partial obstruction
b) Esophageal spasm
e) 24-hour esophageal motility monitoring
i) Advantages
a) Multiplies amount of data
b) Various physiologic conditions
ii) Limitations of stationary monitoring
a) Pt is supine
b) Limited to 10 swallows
iii) Technique
a) Drugs are stopped 48h before test
b) 3 transducers - 5, 10, 15 cm above upper border of LES
c) Pt diary of eating, position, sleeping, symptoms
iv) Diagnostic criteria (Table 39-2)
v) Little correlation with stationary manometry - especially for normal or nutcracker by ambulatory
vi) Primarily useful in pts with noncardiac chest pain
a) Amplitude and duration of contractions associated w/ pain are similar to asymptomatic
b) Frequency of contractions prior to episodes is increased
c) Esophageal claudication
d) Long esophageal myotomy can eliminate ability of esophagus to produce these bursts of abnormal activity
vii) Other findings
a) Esophageal contractility deteriorates with mucosal injury
b) Assess esophageal clearance function = peristaltic contractions with amplitude > 30mm Hg
f) 3-D imaging of LES
i) Overall length or intra abdominal length below 5th percentile can nulify normal LES pressure
ii) Increases the sensitivity of esophageal manometry in identifying pts who will benefit from “early” antireflux surgery (i.e., before the development of mucosal injury)
g) Esophageal pH tests
i) pH electrode withdrawl test
a) Normal is sharp rise in pH from stomach to 5-7 in esophagus
b) 20% false poitive - abandoned
ii) SART
a) pH electrode 5cm above LES - 0.1N Hcl infused into stomach - pt performs maneuvers
b) > 2 drops in pH = abnormal cardia
iii) Acid clearance test
a) Performed after SART
b) Acid infused into esophagus
c) Normal=pH > 5 with < 10 swallows
iv) 24-hour pH monitoring
a) Most sensitive method for reflux-related problems
b) Indications
(1) GERD symptoms, other tests equivocal
(2) Prior to antireflux operation
(3) Atypical GERD symptoms
(4) Dysphagia and motor disorder (?GERD)
(5) Recurrent symptoms after esophageal or gastric surgery
c) Technique
(1) pH electrode 5cm above LES
(2) Acid reflux = pH <4
(3) Alkaline reflux = pH >7
(4) Restrict intake to food pH 5-6
d) Measure
(1) Cumulative time pH < 4 as percentage of time supine, total, upright
(2) Frequency of episodes of pH<4/24h
(3) Duration of longest episode (
4) Number of episodes > 5 min
h) Radionuclide studies
i) Localization of Barrett’s - not used
ii) Dx and quantitation of GERD - not physiologic
iii) Measure esophageal transit - ?screening test prior to manometry
iv) Measurement of gastric emptying
i) Bilirubin monitoring with fiberoptic probe
i) Complications are related to acid and alkaline reflux
ii) 5cm above LES
iii) Uses bilirubin as a marker of exposure to duodenal contents