Upper GI tract Flashcards
Where is the lower oesophageal sphincter (LOS)?
- 3-4 cm distal oesophagus within abdomen
- An intact phrenoesophageal ligament
- Angle of His
What surrounds LOS?
Diaphragm surrounds LOS (Lt & Rt crux)
What is stage 0?
oral phase
What happens during stage 0?
- Chewing & saliva prepare bolus
2. Both oesophageal sphincters constricted
What is stage 1?
Pharyngeal phase
What happens during stage 1?
- Pharyngeal musculature guides food bolus towards oesophagus
- Upper oesophageal sphincter opens reflexly
- LOS opened by vasovagal reflex (receptive relaxation reflex)
What is stage 2?
Upper oesophageal phase
What happens during stage 2?
- Upper sphincter closes
- Superior circular muscle rings contract & inferior rings dilate
- Sequential contractions of longitudinal muscle
What is stage 3?
Lower oesophageal phase
What happens during stage?
Lower sphincter closes as food passes through
What is oesophageal motility determined by?
by pressure measurements (manometry)
What is the pressure of peristaltic waves?
40 mmHg
What is the LOS resting pressure?
20 mmHg
When does the pressure of LOS decrease? What is it mediated by?
- ↓<5 mmHg during receptive relaxation
2. Mediated by inhibitory noncholinergic nonadrenergic (NCNA) neurons of myenteric plexus
What is can functional disorders of oesophagus be caused by?
- Abnormal oesophageal contraction
2. Failure of protective mechanisms for reflux
Why might there by abdnormal oesophageal contraction?
- Hypermotility
- Hypomotility
- Disordered coordination
Why could there be Failure of protective mechanisms for reflux?
GastroOesophageal Reflux Disease (GORD)
What is dysphagia?
difficulty in swallowing
Why is it important to localise dysphagia?
Localisation is important – cricopharyngeal sphincter or distal
What are the types of dysphagia?
-For solids or fluids
-Intermittent or progressive
-Precise or vague in appreciation
What is odynophagia?
pain on swallowing
What is regurgitation?
refers to 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?
hypermobility
What is the cause of achalasia?
- Due to loss of ganglion cells in Aurebach’s myenteric plexus in LOS wall
- leads to decreased activity of inhibitory NCNA neurones
- Cannot relax LOS
What is the primary and secondary causes of achalasia?
• Primary: aetiology unknown
• Secondary
-Diseases causing oesophageal motor abnormalities similar to primary achalasia
•Chagas’ Disease
•Protozoa infection
•Amyloid/Sarcoma/Eosinophilic
Oesophagitis
What happens to the resting pressure of LOS in achalasia?
increased
What is the result of achalasia?
- Receptive relaxation sets in late and is too weak
- During reflex phase pressure in LOS is
markedly higher than stomach
3. Swallowed food collects in oesophagus causing increased pressure throughout with dilation of the oesophagus - Propagation of peristaltic waves cease
What is the disease course of achalasia?
- Has insidious onset - symptoms for years prior to seeking help
- Without treatment: progressive oesophageal dilatation of oesophagus
What happens to the risk of oesophageal cancer in achalasia?
- increased 28-fold
- annual incidence only 0.34%
What is the treatment of achalasia?
pneumatic dilation (PD)
How does pneumatic dilation work?
PD weakens LOS by circumferential stretching & in some cases, tearing of its muscle fibres
How effective is PD?
71 - 90% of patients respond initially but many patients subsequently relapse
What are the surgical options for achalasia treatment?
- Heller’s myotomy
2. Dor fundopilaction
What happens in heller’s myotomy?
A continuous myotomy performed for 6 cm on the oesophagus & 3 cm onto the stomach
What happens in dor fundoplication?
anterior fundus folded over oesophagus and sutured to right side of myotomy
What are the risk of surgical treatment of achalasia?
- Oesophageal & gastric perforation (10 – 16%)
* Division of vagus nerve – rare •Splenic injury – 1 – 5%
What happens in peroral endoscopic myotomy (POEM)?
- Mucosal incision
- Creation of submucosal tunnel
- Myotomy
- Closure of mucosal incision
What is disorder of hypomobility?
Scleroderma
What is scleroderma?
autoimmune disease
What does the scleroderma lead to?
- Hypo mobility in its early stages due to neuronal defects
- Lead to atrophy of smooth muscle of oesophagus
- Peristalsis in distal portion ultimately ceases altogether
- Decreased resting pressure of LOS
- Lead of GORD develop (assoicated with CREST syndrome)
What is the treatment of scleroderma?
- Exclude organic obstruction
- Improve force of peristalsis with prokinetics (cisapride)
- Once peristaltic failure occurs (usually irreversible)_
What can cause disorder coordination?
Corckscrew oesophagus
What does diffuse oesophageal spasm lead to?
•Incoordinate contractions
-dysphagia & chest pain
•Pressures of 400-500 mmHg
•Marked hypertrophy of circular muscle
What is the treatment of corckscrew oesophagus?
- May respond to forceful PD of cardia
- Results not as predictable as achalasia
What vascular anomalies cause dysphagia?
- Dysphagia lusoria
2. Double aortic arch
What is the anatomy of oesophageal perforations?
- 3x areas of anatomical constriction
- cricopharyngeal constriction
- Aortic and bronchial constriction
- Diaphragmatic and ‘sphincter’ constriction - Pathological narrowing (cancer, foreign body, physiological dysfunction)
What are NCNA secreted by?
postganglionic non-cholinergic neurons of the enteric nervous system
What are NCNAs? What are examples
- hormone that affects ‘nerves’
- vasoactive intestinal peptide (VIP), gastrin release peptide (GRP), and enkephalins
What is Chagas’ disease?
South American chronic infection with parasite Trypanosoma Cruzi
What are the symptoms of achalasia?
- dyspha- gia (trouble swallowing)
- regurgitation of food (not vomiting)
- retrosternal pain
- weight loss
What are the serious complications of achalasia?
- esophagitis
2. pneumonia, caused by aspiration of esophageal contents (contain- ing bacteria)
What are the causes of oesophageal perforation?
- Iatrogenic (OGD) >50%
- Spontaneous (Boerhaave’s) - 15%
- Foreign body - 12%
- Trauma - 9%
- Intraoperative - 2%
- Malignant - 1%
When is the the oesophageal perforation latrogenic?
-Usually at OGD
-More common in presence of
diverticula or cancer
What is the incidence of latrogenic oesophageal?
- OGD = 0.03%
- Stricture dilatation = 0.1-2% 3, Sclerotherapy = 1-5%
- Achalasia dilatation = 2-6%
What happens in Boerhaave’s?
- Sudden increase in intra-oesophageal pressure with negative intra thoracic pressure
- Vomiting against a closed glottis
- Massive pressure
How common is Boerhaave’s?
3.1 per 1,000,000
What sort of foreign bodies are found in oesophageal perforations?
• Disk batteries growing problem • Cause electrical burns if impact in mucosa •Magnets •Sharp objects •Dishwasher tablets •Acid/Alkali
What sort of trauma would cause neck oesophageal perforation?
penetrating
What sort of trauma would cause thorax oesophageal perforation?
blunt force
Why can it be difficult to diagnose oesophageal perforations- what do you look out for?
- Dysphagia
- Blood in saliva
- Haematemesis
- Surgical empysema
What sort surgeries can cause oesophageal perforation?
•Hiatus hernia repair
•Hellers Cardiomyotomy
•Pulmonary surgery
•Thyroid surgery
When can there be malignant oesophageal perforation?
- Advanced cancers
- Radiotherapy
- Dilatation
- Stenting
- Poor prognosis
When does the oesophagus start and end?
C5-T10 and around 25cm
What do you need to make sure when diagnosing a functional disorder of oesophagus?
absence of stricture
What are some proposed ideas of the model of achalasia pathophysiology?
- environmental trigger
- Genetic predisposition
1. Then non autoimmune inflammatory infiltrates
2. This promotes wound repair and fibrosis
3. Then loss of immunological tolerance
4. Then autoimmune so causes apoptosis
5. Then get humoral response
6. Then get autoimmune myenteric plexistis/gangolitis vascultisis etc