Upper GI Tract Flashcards
What is the angle of His and what does it contribute to the LOS?
The angle between the abdominal stomach and the fundus of the stomach
It prevents reflux
How does the diaphragm contribute to the efficacy of the LOS?
The left and right crux of the diaphragm contract against the sphincter to help its efficacy
What ligament allows the diaphragm and LOS to move independently of each other?
Phrenoesophageal ligament
What are the stages of swallowing?
Stage 0: Oral phase
Stage 1: Pharynx phase
Stage 2: Upper oesophageal phase
Stage 3: Lower oesophageal phase
What is manometry and its units?
A test to measure the motility and muscle contractions of the oesophagus
in mmHg
What is the usual manometry value for peristaltic waves?
around 40 mmHg
What is the resting pressure of the LOS?
around 20 mmHg
What is the role of the noncholinergic noradrenergic neurones (NCNA) of the myenteric plexus?
They mediate the decrease of LOS pressure (to <5 mmHg) during receptive relaxation
They are inhibitory neurones
What is receptive relaxation?
The Vagus nerve is activated when food is swallowed and relaxes stomach muscle to prepare for bolus.
What is the state of the oesophageal sphincters during stage 0 of swallowing?
Both oesophageal sphincters are constricted
What is the state of the oesophageal sphincters during stage 1 of swallowing?
Upper oesophageal sphincter opens on reflex
LOS is opened by the receptive relaxation reflex
What is the state of the oesophageal sphincters during stage 2 of swallowing?
Upper sphincter closes
What is the state of the oesophageal sphincters during stage 3 of swallowing?
Lower sphincter closes as food passes through
What happens to the muscles during stage 2 of swallowing?
Peristalsis:
Superior circular muscle rings contract
Inferior circular muscle rings dilate
Longitudinal muscles contract sequentially - (act antagonistically, contracting ahead of the bolus)
What is the effect of cholinergic fibres on sphincters?
Increase contraction of sphincter - exciting shortening of fibres
What causes Achalasia?
A loss of ganglionic cells in Aurebach’s myenteric plexus.
Decreased activity of inhibitory NCNA neurones
LOS remains constricted
What is Achalasia?
Hypermotility of oesophageal muscles
What are the causes of Achalasia?
Primary - aetiology unknown
Secondary -
Chagas’ Disease
Protozoa infection
Amyloid/Sarcoma/Eosinophilic Oesophagitis
How does Achalasia affect oesophageal motility?
Increases resting pressure of the LOS (pressure in LOS much higher than in stomach)
Delay in receptive relaxation and decrease in effect
Increased pressure in oesophagus caused by collection of swallowed food
Propagation of peristaltic waves ceases
What are the symptoms of Achalasia?
weight loss
dysphagia
regurgitation
retrostomach pain
What is Chagas’ disease
Infection by a parasite (Trypanosoma cruzi) that causes damage to the heart, oesophagus and other digestive tracts
What is Amyloid Oesophagitis?
Deposits of amyloid in the oesophagus (in the submucosa), puts pressure on and causes destruction of surrounding cells
What is Sarcoma Oesophagitis?
A form of malignant neoplasm arising from the oesophagus
What is the pathophysiology of Chagas’ disease?
The parasite damages the oesophageal myenteric plexus, causing:
- loss of esophageal peristalsis
- partial or absent lower esophageal sphincter relaxation
- megaesophagus - secondary oesophageal achalasia
What is the pathophysiology of Chagas’ disease?
The parasite damages the oesophageal myenteric plexus, causing:
- loss of oesophageal peristalsis
- partial or absent lower oesophageal sphincter relaxation
- megaoesophagus - secondary oesophageal achalasia
How is Achalasia treated?
Pneumatic Dilatation
Surgery
What is Pneumatic Dilatation?
An air-filled cylinder shaped balloon forcefully dilates the LOS and weakens it by circumferential stretching.
Forceful dilation tears the muscle fibres but doesn’t damage the mucosa
How effective is Pneumatic Dilatation?
71-90% respond initially but many relapse
What surgeries are given for Achalasia?
Heller’s Myotomy with Dor fundoplication
Peroral endoscopic myotomy (POEM)
What is Heller’s Myotomy?
A continuous myotomy for 6cm on oesophagus and 3cm of stomach
Remove muscles and leave only mucosa
What are the risks for Achalasia surgery?
Oesophageal perforation (10-16%) Division of vagus nerve (rare) Splenic injury (1-5%)
What is Dor fundoplication?
attach anterior fundus to right side of myotomy on oesophagus
What is Peroral endoscopic myotomy?
minimally invasive procedure to divide the inner muscle layer of the LOS through a submucosal tunnel.
What is the disease course of Achalasia
insidious onset
progressively dilates oesophagus without treatment
increases risk of oesophageal cancer 28 fold
What is the annual incidence of oesophageal cancer?
0.34%
What is Scleroderma?
An autoimmune disease causing hardening and tightening of skin and connective tissues.
How does early stage hypomotility affect the oesophagus?
Atrophy of smooth muscle of oesophagus
How does Scleroderma affect the oesophagus?
No peristalsis in distal oesophagus
Decrease resting pressure of LOS (can cause GORD)
What is CREST syndrome?
C - Calcinosis R - Raynaud's phenomenon E - Oesophageal dysmotility S - Sclerodactyly T - Telangiectasias
What is Calcinosis?
Calcium deposits in the skin (hard nodules under skin)
What is Raynaud’s phenomenon?
Spasms of blood vessels in response to cold or stress
What is Oesophageal dysmotility?
Acid reflux and decreased motility of oesophagus
What is Sclerodactyly?
Thickening and tightening of skin on hands and fingers
What is Telangiectasias?
Dilatation of capillaries causing red marks on the skin
How is Hypomotility treated?
Exclude organic obstruction
Cisapride (prokinetic to improve force of peristalsis)
Once peristaltic failure occurs its usually irreversible
What is Corkscrew Oesophagus?
A type of disordered contraction
Diffuse oesophageal spams with incoordinate contractions
What are the symptoms of Corkscrew Oesophagus?
Dysphagia
Chest pain
What manometric changes are seen in Corkscrew Oesophagus?
Pressures of 400-500 mmHg
What cellular changes occur in Corkscrew Oesophagus?
Marked hypertrophy of circular muscle
What is the treatment for Corkscrew oesophagus?
Pneumatic Dilatation may be effective
Results are unpredictable
What vascular anomalies can cause dysphagia?
Dysphagia Lusoria
Double Aortic arch
What is Dysphagia Lusoria?
An aberrant right subclavian artery compresses the oesophagus
What are the 3 areas of oesophageal constriction?
Cricopharyngeal
Aortic and bronchial
Diaphragmatic and sphincter
What are they 3 types of pathological narrowing of the oesophagus?
Cancer
Foreign body
Physiological dysfunction
What are the different causes of Oesophageal perforation?
Iatrogenic - >50% Spontaneous (Boerhaave's) - 15% Foreign body - 12% Trauma - 9% Intraoperative - 2% Malignant - 1%
What is Iatrogenic Oesophageal Perforation?
Perforation of the oesophagus as a result of endoscopy and other investigations
More common if diverticula or cancer are found
What investigations can cause Iatrogenic Oesophageal Perforation?
Endoscopy - 0.03%
Stricture dilatation - 0.1-2%
Sclerotherapy - 1-5%
Achalasia dilatation - 2-6% (more interventions increase likelihood of perforation)
What is Boerhaave’s syndrome?
Sudden increase in intra-oesophageal pressure with negative intra-thoracic pressure
Rupture of oesophagus due to forceful vomiting against a closed epiglottis
What part of the oesophagus is Boerhaave’s syndrome likely to affect?
Left posterolateral aspect of the distal oesophagus
What foreign objects are likely to cause oesophageal perforation?
Disk batteries - electrical burns if in contact with mucosa Magnets Sharp objects Dishwasher tablets Acid/Alkali
What differentiates penetrating trauma from blunt force trauma?
Neck - penetrating
Thorax - blunt force
What are the symptoms of trauma causing oesophageal perforation?
Dysphagia
Blood in saliva
Haematemesis
Surgical emphysema
What operations may cause Oesophageal perforation?
Hiatus hernia repair
Heller’s Cardiomyotomy
Pulmonary surgery
Thyroid surgery
What is dysphagia?
difficulty swallowing
