gastroenterology

Question 1

at what level does the oesophagus start and when does it end

Answer 1

start at C6
ends at t10 (where it enters diaphragm at oesophageal hiatus)
27cm length

Question 2

how is the oesophagus divided and what muscle is present in each one

Answer 2

upper third - skeletal
middle third - skeletal and smooth
lower third - smooth

Question 3

what is the mucosa of the upper third

Answer 3

non keratinising squamous epithelium

Question 4

what is the mucosa of the lower third

Answer 4

columnar epithelium

Question 5

what is between the pharynx and the upper oesophagus and what is it composed of

Answer 5

upper oesophageal sphincter
composed of thyropharyngeos and cricopharyngeos muscle

Question 6

where are some normal places of constriction (if you swallowed something for eg)

Answer 6

• level of cricoid
• level of left main atrium/main bronchus
• t10 where it enters diaphragm

Question 7

what is the angle at which the LOS enters the diaphragm

Answer 7

angle of His

Question 8

what do the right and left crux of the diaphragm do

Answer 8

surrounds the LOS forming a muscular ring (mainly right)

Question 9

what is the phrenooesophageal ligament

Answer 9

connective tissue covering oesophagus

Question 10

how many cm are there of abdominal oesophagus

Answer 10

3-4cm

Question 11

describe the stages of swallowing

Answer 11

stage 0 = oral phase
- chewing and saliva prepare bolus
- both UOS and LOS constricted
stage 1 = pharygneal phase
- pharyngeal musculature guides food bolus towards oesophagus
- UOS opens reflexly
- LOS opens by vasovagal reflex (receptive relaxation reflex)
stage 2 = upper oesophageal phase (autonomic)
- upper sphincter closes
- superior circular muscle rings contract and inferior rings dilate
- sequential contractions of longitudinal muscle
stage 3 = lower oesophageal phase (autonomic)
- lower sphincter closes as food passes through

important to note there is an initial relaxation phase then coordinated peristalsis

Question 12

how do we determine oesophageal motility
normal range for peristalsis waves and LOS resting pressure

Answer 12

pressure measurements (manometry)

peristaltic waves - 40 mmHg
LOS resting pressure - 20 mmHg
decreases by <5 mmHg during receptive relaxation
mediated by inhibitory noncholinergic nonadrenergic (NCNA) neurons of myenteric plexus

Question 13

what is the most common disorder of the oesophagus

Answer 13

reflux

Question 14

how would you describe GORD

Answer 14

failure of protective mechanisms for reflux

Question 15

what is dysphagia

Answer 15

difficulty in swallowing
- location important - cricopharyngeal sphincter or distal
type of dysphagia
- for solids or fluids
- intermittent or progressive (red flag symptom for oesophageal cancer)

Question 16

what is odynophagia

Answer 16

pain on swallowing

Question 17

what is regurgitation

Answer 17

return of oesophageal contents from above an obstruction
- can be functional or mechanical

Question 18

what is reflux

Answer 18

passive return of gastroduodenal contents to the mouth

Question 19

what is achalasia

Answer 19

failure of LOS to relax and some abnormality of peristalsis
loss of inhibitory ganglion cells in Aurebachs myenteric plexus in LOS wall
(decreased activity of inhibitory NCNA neurones)
increased resting pressure of LOS
peristaltic waves cease

• cause unknown
  secondary causes
• diseases causes oesophageal motor abnormalities similar to primary achalasia
• chagas disease (caused by parasite - secondary achalasia)
• protozoa infection
• amyloid/sarcoma/eosinophillic oesophagitis

Question 20

what would you see in a barium swallow for achalasia

Answer 20

bird beak appearance
tapering of distal oesophagus and dilating oesophagus
late feature of achalasia :. not diagnostic

Question 21

during the reflex phase how would you compare the pressure in the LOS to the stomach

Answer 21

during the reflex phase the pressure in LOS is markedly higher than in the stomach

Question 22

what causes swallowed foods to collect in the oesophagus in achalasia

Answer 22

increased pressure throughout with dilation of the oesophagus
causing bacterial overgrowth and bad smells

Question 23

what is the disease onset of achalasia

Answer 23

insidious onset
without treatment –> progressive oesophageal dilation of oesophagus

Question 24

what is achalasia a risk factor for

Answer 24

squamous oesophageal cancer

Question 25

what are some treatments for achalasia

Answer 25

palliative treatments
PD - pneumatic dilation = PD weakens LOS by circumferential stretching and sometimes muscle fibre tearing (risk of perforation)
surgery - Hellers myotomy (laparascopic procedure) - 6cm on oesophagus and 3cm on stomach
dor fundoplication - anterior fundus is folder over the oesophagus and sutured onto the right side of myotomy (anti reflex, safe and effetive) but risks = perforation (gastric and oesophageal), division of vagus nerve, splenic injury

Question 26

what is scleroderma

Answer 26

an autoimmune disease
- hypomotility in its early stages due to neuronal defects –> atrophy of smooth muscle of oesophagus
- peristalsis in the distal portion ultimately ceases altogether
- decreased resting pressure of LOS
- leads to gastroesophageal reflux disease (often associated with CREST syndrome)

Question 27

what is the treatment for scleroderma

Answer 27

• exclude organic obstruction
• improve force of peristalsis with prokinetics (cisapride)
• often peristaltic failure occurs –> usually irreversible

Question 28

what is corkscrew oesophagus

Answer 28

diffuse oesophageal spasm
- incoordinate contractions which lead to dysphagia and chest pain
- marked hypertrophy of circular muscle
- corkscrew oesophagus on barium
- pressures of 400-500 mmHg

Question 29

what is the treatment for corkscrew oesophagus

Answer 29

may respond to forceful PD of cardia
- results are not as predictable as achalasia

Question 30

what are the 3 anatomical areas of constriction

Answer 30

cricopharyngeal constriction (upper OS)

aortic and bronchial constriction

diaphragmatic and sphincter constriction

Question 31

where are the most likely places for oesophageal perforations

Answer 31

the 3 areas of constriction

Question 32

what are some causes of oesophageal perforations (most common at the top)

Answer 32

iatrogenic (OGD) >50%
spontaneous (Boerhaaves)
foreign body
trauma
intraoperative
malignant