Upper GI Tract Flashcards
How long is the oesophagus?
Approx. 27 cm
At what level does the oesophagus enter the abdominal region?
T10
What are the anatomical contributions to the lower oesophageal sphincter?
3-4 cm distal oesophagus within abdomen
Diaphragm surrounds LOS (Lt & Rt crux)
An intact phrenoesophageal ligament
Angle of His - angle at which oesophagus enters stomach
Describe the phases of swallowing
Stage 0: Oral phase
- Chewing & saliva prepare bolus
- Both oesophageal sphincters constricted
Stage 1: Pharyngeal phase
- Pharyngeal musculature guides food bolus towards oesophagus
- Upper oesophageal sphincter opens reflexly
- LOS opened by vasovagal reflex (receptive relaxation reflex)
Stage 2: Upper oesophageal phase
- Upper sphincter closes
- Superior circular muscle rings contract & inferior rings dilate
- Sequential contractions of longitudinal muscle
Stage 3: Lower oesophageal phase
- Lower sphincter closes as food passes through
How do you assess oesophageal motility?
Manometry - motility is determined by pressure measurements
What is the approximate pressure of peristaltic waves?
40 mmHg
What is the resting pressure of the LOS and what is it mediated by?
20mmHg
Drops <5mmHg during receptive relaxation
Mediated by inhibitory noncholinergic nonadrenergic neurons (NCNA) of myenteric plexus
What is dysphagia?
Difficulty when swallowing
What is important to consider when taking a history of dysphagia?
Localisation - cricopharyngeal sphincter or distal
Types of dysphagia:
- Solids or fluids
- Intermittent or progressive (red flag for OC)
- Precise or vague in appreciation
What is odynophagia?
Pain on swallowing
What is regurgitation?
Return of oesophageal contents from above an obstruction
May be functional or mechanical
What is reflux?
Passive return of gastroduodenal contents to the mouth
What is achalasia?
A condition characterised by the failure of the LOS to relax plus some abnormality in oesophageal peristalsis
What is the primary cause of achalasia?
Unknown
What is the pathophysiology of achalasia?
Loss of ganglion cells in Auerbach’s myenteric plexus in LOS wall
Leads to decreased activity of inhibitory NCNA neurons
What are the secondary causes of achalasia?
Chagas’ Disease - caused by parasites
Protozoa infections
Amyloid/sarcoma/eosinophilia
Oesophagitis
Diseases cause oesophageal motor abnormalities similar to primary achalasia
When a person with achalasia undertakes a barium swallow, how does the oesophagus appear?
Bird’s beak appearance - tapering of distal oesophagus and dilated oesophagus proximal to this
Must a person have a bird beak appearance of their oesophagus in order to be diagnosed with achalasia?
No, shouldn’t be used as a diagnostic tool, instead perform manometry
Person can have achalasia with a normal barium swallow
Bird beak appearance is a later stage sign
What is achalasia a risk factor of?
squamous oesophageal cancer
What happens when a person with achalasia eats?
Increased resting pressure of LOS
During reflex phase, pressure in LOS is much greater than in stomach as receptive relaxation sets in too late (and is too weak)
Swallowed food collects in oesophagus - increases pressure and causes dilation
Propagation of peristaltic waves cease
N.B. three types of achalasia - absence of peristaltic waves is one type
Describe the disease course of achalasia
Insidious onset - symptoms can persist for years before seeking help
Without treatment -> progressive oesophageal dilation
Increases oesophageal cancer risk 28x
What is a risk of food build-up in oesophagus?
Bacterial overgrowth - people may report a bad smell
is there a cure for achalasia?
No, all treatments are palliative and designed to relieve symptoms
How does pneumatic dilatation work?
Treatment for achalasia
Weakens LOS by circumferential stretching and in some cases tearing of muscle fibres
Patients receive it every few months
Majority of patients respond initially and then later relapse
What is a risk of pneumatic dilatation?
Perforation of oesophagus
What is Heller’s Myotomy and what procedure is often carried out in addition to prevent acid reflux?
Continuous myotomy (division of muscle) performed for 6cm of oesophagus and 3cm of stomach
Dor fundoplication is carried out alongside to prevent reflux -> anterior fundus is folded over oesophagus and sutured to the right side of myotomy
What are the risks of Heller’s Myotomy?
Oesophageal and gastric perforation
Division of vagus nerve - rare
Splenic injury
What is Scleroderma?
Autoimmune disease
Smooth muscle atrophy
Hypomotility in early stages due to neuronal defects
Peristalsis in distal oesophagus ultimately ceases
Decreased resting pressure of LOS
Development of GORD
What condition is Scleroderma often associated with?
CREST syndrome