Seminar on esophageal function and pathophysiology of GERD

1. Seminar on Structural & Functional assessment of
esophageal disorders,
Human Antireflux mechanisms & Pathophysiology of GERD
 Moderated by : Dr. Amitava Ghosh, Prof. & Head, Deptt. Of Surgery
SMCH
 Presented by : Dr. Soumen Kanjilal, PGT, Deptt. Of Surgery
SMCH
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2. ASSESSMENT OF ESOPHAGEAL FUNCTION
 The diagnostic tests can be divided into 4 broad groups :-
1) Tests to detect structural abnormalities of the esophagus.
2) Tests to detect functional abnormalities of the esophagus.
3) Tests to detect increased esophageal exposure to gastric juice.
4) Tests of duodenogastric function as they relate to esophageal
disease.

3. TESTS TO DETECT STRUCTURAL ABNORMALITIES
 Mainly –
a) ENDOSCOPIC EVALUATION
b) RADIOLOGICAL EVALUATION

5. UGI ENDOSCOPE
 Two types :
a) Rigid endoscope
b) Flexible endoscope

6. UGI ENDOSCOPY
 It is the first diagnostic test.
 Allows assessment and biopsy of the mucosa of the stomach and
the esophagus.
 Allows diagnosis and assessment of obstructing lesions in the
upper gastrointestinal tract.

8. BARIUM SWALLOW
 It is undertaken selectively to assess anatomy and motility.
 Advantages –
 Anatomy of large hiatal hernias are more clearly demonstrated by contrast
radiology than endoscopy and even better in prone position.
 The presence of coordinated esophageal peristalsis can be determined by
observing several individual swallows of barium traversing the entire
length of the organ.

9. BARIUM SWALLOW
 Full column technique :- Esophageal disorders shown clearly by a full-column technique
include -
a) circumferential carcinomas,
b) peptic strictures,
c) large esophageal ulcers and
d) hiatal hernias.
 Lesions extrinsic but adjacent to the esophagus can be reliably detected by the full-column
technique if they contact the distended esophageal wall.
 Limitations –
1. Small esophageal neoplasms
2. Esophagitis and
3. Esophageal varices
Double
contrast
film

10. An extension to Barium Swallow…….
Patient complains of dysphagia
No obstructing lesion on barium swallow
Patient is asked to swallow, Ba impregnated
Marshmallow
Bread or
Hamburger with Ba within it
Assessment of functional disturbance of esophagus

11. TESTS TO DETECT FUNCTIONAL ABNORMALITIES
 Tools available for detecting esophageal functional abnormalities are :
1. Manometry
a) Stationary manometry
b) High resolution manometry.
2. Esophageal Impedance
3. Esophageal Transit Scintigraphy
4. Video and Cine Radiography

12. ESOPHAGEAL MANOMETRY

13. MANOMETRY
 Esophageal manometry is a widely used technique to examine the motor
function of the esophagus and its sphincters.
 The utility of esophageal manometry in clinical practice resides in 3 domains:
(1) to accurately define esophageal motor function,
(2) to define abnormal motor function and
(3) to delineate a treatment plan based on motor abnormalities.
 It is performed using –
a) electronic, pressure-sensitive transducers located within the catheter, or
b) water-perfused catheters with lateral side holes attached to transducers
outside the body.

14. TYPES OF MANOMETRY
1. Stationary Manometry :
 It consists of a train of five pressure transducers or five or more water-perfused tubes
bound together.
 The transducers or lateral openings are placed at 5cms intervals from the tip and
oriented radially at 72° from each other around the circumference of the catheter.
2. High Resolution Manometry : increased number of recording sites and
added three-dimensional assessment.
 It contains 36 miniaturized pressure sensors positioned every centimeter along the
length of the catheter.
 It allows the identification of focal motor abnormalities previously overlooked.
 It has enhanced the ability to predict bolus propagation and increased sensitivity in the
measurement of pressure gradients.

15. 3. Esophageal Impedance Manometry :
 Multichannel intraluminal impedance (MII) detects GER episodes based on changes
in electrical resistance to the flow of an electrical current between 2 electrodes
placed on the MII probe, when a liquid, semisolid, or gas bolus moves between
them.
 Combined esophageal PH and impedance monitoring devices are available.
 It offers following advantages :
a) It enables detection of reflux regardless of its pH value.
b) It enables to distinguish swallows (antegrade flow) from authentic GER (retrograde
flow).
c) It can detect accurately the height of the refluxate.
d) It is able to determine whether the refluxate is liquid, gas, or mixed (both liquid and
gas).
e) It can still measure symptom association with GER even while the patient is taking
acid-suppression medications.

16. Interpretation of Impedance Manometry
 Impedance is measured in ohms.
 Reflux - A reflux episode by impedance is defined as a fall in intraluminal
impedance of ≤50% of baseline that progresses retrograde across 2 or more
of the distal-most channels.
 Acid Reflux - When the esophageal pH decreases and remains <4 for at least
5 seconds.
 Non-Acid Reflux - When the pH increases, remains unchanged, or decreases
by <1 pH unit while remaining ≥4.

18. Esophageal Transit Scintigraphy
 The esophageal transit of 10-mL water bolus containing technetium-
99m (99mTc) sulfur colloid is recorded with a gamma camera.
 Using this technique, delayed bolus transit in a variety of esophageal
motor disorders including :-
 Achalasia,
 Scleroderma,
 DES and
 nutcracker esophagus.

19. VIDEO and CINE RADIOGRAPHY
 High-speed cinematic or video recording of radiographic studies allows re-
evaluation by reviewing the studies at various speeds.
 This technique is more useful than manometry in the evaluation of the
pharyngeal phase of swallowing.
 Helpful in diagnosis of –
a) Zenker’s diverticulum
b) Narrow pharyngoesophageal segment and
c) Stasis of the contrast in vallecula or hypopharyngeal recess ( cricopharyngeal
Achalasia)

20. Tests to Detect Increased Exposure
to Gastric Juice
 24-Hour Ambulatory pH Monitoring :
 Detected with the use of –
a) Indwelling PH electrode in the esophagus.
b) Radio-telemetric PH monitoring capsule.
 This allows measuring the effect of physiologic activity, such as eating or sleeping, on the
reflux of gastric juice into the esophagus.
 The measurement is expressed by the time the esophageal pH was below a given
threshold during the 24-hour period.

21. Interpretation
 The units used to express esophageal exposure to gastric juice are:
(a) cumulative time the esophageal pH is below a chosen threshold,
expressed as the percentage of the total, upright, and supine monitored
time;
(b) frequency of reflux episodes below a chosen threshold, expressed as
number of episodes per 24 hours; and
(c) duration of the episodes, expressed as the number of episodes >5 minutes
per 24 hours, and the time in minutes of the longest episode recorded.

22. Tests of
Duodenogastric
Function

23.  Esophageal disorders are frequently associated with abnormalities of
duodenogastric function.
 Abnormalities of the gastric reservoir or increased gastric acid secretion can be
responsible for increased esophageal exposure to gastric juice.
 Reflux of alkaline duodenal juice, including bile salts, pancreatic enzymes, and
bicarbonate.
 Gastric Emptying : Gastric emptying studies are performed with radionuclide-
labeled meals.
 gamma camera images of the stomach are obtained at 5- to 15-minute intervals for 1.5
to 2 hours.
 24-Hour Gastric pH Monitoring : Monitoring is performed over a complete
circadian cycle with a pH electrode placed 5 cm below the manometrically
located LES.

24. Various Esophageal Disorders

25. ESOPHAGITIS
 Severity and length of involved esophagus is recorded.
 Grading of the esophagitis.

26. Grading of Esophagitis
 Grade I - small, circular, nonconfluent erosions.
 Grade II – linear erosions lined with granulation tissue that bleeds easily
when touched.
 Grade III - the linear erosions coalesce into circumferential loss of the
epithelium and the mucosa may take a “cobblestone” appearance.
 Grade IV - presence of a stricture.
- The absence of esophagitis above a stricture suggests a chemical – induced
injury or Neoplasm.

27. BARRETT’S ESOPHAGUS
 Barrett’s esophagus is a condition in which the tubular esophagus is
lined with columnar epithelium, as opposed to the normal squamous
epithelium.
 Histologically – Intestinal metaplasia.
 Endoscopically suspected –
 Difficulty in visualizing the squamocolumnar junction at its normal location.
 Appearance of a redder, more luxuriant mucosa.
Uncomplicated Barrett’s High Grade Dysplasia in Barrett’s mucosa

28. GASTROESOPHAGEAL FLAP VALVE
 Abnormalities of the gastroesophageal flap valve is visualized by
retroflexion of the endoscope.
 Hill grading based according to the degree of unfolding or deterioration
of the normal valve architecture.

29. Hill grading of Gastroesophageal Flap valve
 Grade I – closely approximated ridge of tissue to the shaft of the retroflex
endoscope.
 Grade II – ridge is slightly less well defined than in grade I and it opens rarely
with respiration and closes promptly.
 Grade III – ridge is barely present, and there is often failure to close around the
endoscope.
 Grade IV – no muscular ridge present.

30. Diffuse Esophageal Spasm
 Most common in women.
 Pathology – muscular hypertrophy and degeneration of vagus nerve in the
esophagus.
 Most notable in lower 2/3
rd of the esophagus.
 Clinical Presentation :
 Chest Pain
 Dysphagia
 Regurgitation of saliva but not acid reflux.

31.  Diagnosis :
1) Manometry : simultaneous multipeaked contractions of high amplitude ( > 120
mm Hg) or long duration (>2.5 seconds).
2) Radiography : Corkscrew esophagus or Pseudodiverticulosis.

32. Nutcracker Esophagus
 Also known as Jack-hammer esophagus.
 Characterised by excessive contractility.
 described as an esophagus with hypertensive peristalsis or high amplitude
peristaltic contractions.
 Most common and most painful
 Associated with hypertrophic musculature.
 Clinical features :
a) Chest pain
b) Dysphagia
c) Odinophagia

33.  Diagnosis :
Manometry :
a) Distal contractile integral > 8000 mm Hg.s.cm with single
or multipeaked contractions
b) LES pressure is normal and relaxation occurs with each
wet swallow.

34. ACHALASIA CARDIA
 Literal meaning failure to relax
 Pathology :
a) Destruction of nerve to LES
b) Degeneration of the neuromuscular function of the body of the esophagus.
 Clinical features :
 Classical triad
a) Dysphagia
b) Regurgitation
c) Weight loss

35.  Diagnosis :
1. Oesophagogram :
 Classical Bird’s beak appearance ( dilated esophagus with distal narrowing)
 Lack of gastric air bubble on upright position.
2. Manometry :
 LES is hypertensive, pressure > 35 mm of Hg.
 Fail to relax with deglutition.
 Body of esophagus has pressure above baseline from incomplete air evacuation.
 Simultaneous mirrored contractions with no evidence of progressive peristalsis.
 Low – amplitude waveforms – Lack of muscle tone.
3. Endoscopy

36. INEFFECTIVE ESOPHAGEAL MOTILITY
 Defined as contraction abnormality of the distal esophagus and is usually
associated with GERD.
 Pathology :
- Increased exposure to gastric contents
Inflammatory injury of esophageal body
- Dampened esophageal motility poor acid clearance in the lower esophagus
- IRREVERSIBLE

37.  Clinical Features :
1. Reflux
2. Dysphagia
3. Heartburn
4. Chest pain
5. Regurgitation
 Diagnosis :
1. Manometry :
- Defined by > 50% of swallows being deemed ineffective
- Distal contractile integral < 450 mm.Hg.s.cm
2. Barium Esophagogram :
- non-specific abnormalities of esophageal contraction

38. PHARYNGOESOPHAGEAL (ZENKER) DIVERTICULUM
 Most common esophageal diverticulum
 Usually seen in old patients (7th decade)
 As a result of loss of tissue elasticity and muscle tone
 Herniates from Killian’s triangle between oblique fibres of thyropharyngeus
and horizontal fibres of cricopharyngeus.
Diverticulum enlarges mucosal and submucosal layers
left side of esophagus dissect down
posteriorly in prevertebral space superior mediastinum
 Also known as Cricopharyngeal Achalasia

39.  Clinical Feature :
1. Usually asymptomatic initially.
2. Sticking in throat Early complaint
3. Nagging cough
4. Excessive salivation Progressive disease
5. Intermittent dysphagia
6. Hallotosis, voice changes, retrosternal pain
7. Regurgitation of foul smelling, undigested material.
8. Aspiration pneumonia
9. Lung abscess Complications
 Diagnosis :
 Barium esophagram :-
- Cricopharyngeal bar – barium resting posteriorly alongside the
esophagus

40. HIATAL HERNIA
 It refers to herniation of the abdominal content into the mediastinum
through esophageal opening (Hiatus) of the diaphragm.
 There are three types of hiatal hernia :
 Type I – also known as sliding hernia, it is said to be present when the GE junction is
not maintained in the abdominal cavity.
 Type II – also known as rolling hernia, it occurs when the GE junction is anchored in
the abdomen but the hiatal defect provides space for viscera to migrate into
mediastinum.
 Type III – it is a combination of the above two, in which the GE junction and fundus
or other viscera are free to move into the mediastinum.

42. Hiatal Hernia
 It Is endoscopically confirmed by finding a pouch lined with gastric folds
lying 2cm or more above the margins of the diaphragmatic crura.
 Best demonstrated with the stomach fully insufflated and the GE
junction observed with a retroflexed endoscope.

43. HUMAN ANTI-REFLUX MECHANISM

44.  The anti-reflux mechanism prevents the retrograde flow of the gastric content into
the esophagus.
 It is composed of three components–
1. A mechanically effective LES
2. Efficient esophageal clearance
3. Adequately functioning gastric reservoir.
 There is a high-pressure zone located at the esophagogastric junction in humans –
Lower Esophageal Sphincter.
 There are three characteristics of the LES that work in unison to maintain its barrier
function.
a) resting LES pressure,
b) its overall length and the intra-abdominal length that is exposed to the positive
pressure environment of the abdomen.
c) another characteristic of the LES that impacts its ability to prevent reflux is its position
about the diaphragm

45.  A permanently defective sphincter is defined by one or more of the following
characteristics:
A. An LES with a mean resting pressure of less than 6 mmHg,
B. An overall sphincter length of <2 cm and
C. Intra-abdominal sphincter length of <1 cm.

46. GASTROESOPHAGEAL REFLUX DISEASE

47. GASTROESOPHAGEAL REFLUX
 GER occurs when intra-gastric pressure is greater than the high pressure zone of the
distal esophagus.
 This develops under two conditions –
a) The LES resting pressure is too low ( Hypotensive LES)
b) The LES relaxes in the absence of peristaltic contraction of the esophagus
(Spontaneous LES relaxation).
 GER is a normal physiological process that occurs even in the setting of a normal LES.
 Distinction from pathologic reflux hinges on :
a) The total amount of esophageal acid exposure
b) The patient’s symptoms and
c) Presence of mucosal damage of the esophagus.

48. Pathophysiology of GER
In the setting of defective LES
Associated with reduced
esophageal body function
Decrease clearance times
of refluxed material
In the setting of normal LES
Functional problem of gastric emptying
or excessive air swallowing
Gastric
distention
Increased intra-
gastric pressure
Resultant shortening or
unfolding of the LES
Reflux

49. Pathophysiology contd….
 Mechanism by which gastric distention contributes to LES unfolding
provides a mechanical explanation for “transient LES relaxation.”
Large meal volume or Chronic air swallowing
Repeated gastric distention
Repeated unfolding of the LES and subsequent
attenuation of the collar sling musculature
Pathologic and severe
postprandial reflux disease
Physiologic mechanism of
gastric venting