upper GI Flashcards
What are the upper/middle/lower parts of oesophagus made of muscle wise?
Upper part - skeletal. Middle - skeletal + smooth. Lower - smooth.
What are the contributions to the lower oesophageal sphincter?
- 3-4cm distal oesophagus within abdomen (abdominal oesophagus)
- diaphragm surrounds LOS (contracts against LOS more effective)
- intact phrenoesophageal ligament
- angle of His (normally acute angle between abdominal oesophagus and fundus of stomach - prevents reflux)
What are the phases of swallowing and what happens at each phase?
Stage 0: oral phase - chewing & saliva prepare bolus (both UOS and LOS constricted). Stage 1: pharyngeal phase - guides bolus to oesophagus - UOS opens reflexly & LOS opened by vasovagal reflex (receptive relaxation reflex). Stage 2: upper oesophageal phase - UOS closed and superior circular muscle rings contract & inferior rings dilate - sequential contraction of longitudinal muscle guides bolus down. Stage 3 - lower oesophageal phase - LOS closes as food passes through
What is motility of the oesophagus determined by clinically?
Manometry - measures/records pressure of contractions during swallowing.
What is normal peristaltic wave pressure? Normal LOS resting pressure? When does LOS resting pressure decrease?
Normal peristaltic wave pressure = 40mmHg. Normal LOS resting pressure = 20mmHg. Decreases more than 5mmHg during receptive relaxation of LOS mediated by inhibitory non-cholinergic non-adrenergic neurones (NCNA) of myenteric plexus
What can abnormal oesophageal contraction be divided into?
Hypermotilty, hypomotility, disordered coordination or failure of protective mechanisms for reflux
What is dysphagia? How do we differentiate between types?
Difficulty swallowing. Localisation important (proximal, distal) and type (solids, fluids, both, intermittent/progressive, vague/precise)
What is odynophagia?
Pain when swallowing
What is regurgitation?
Return of oesophgeal contents from above an obstruction
What is reflux?
Return of gastroduodenal contents to the mouth
What is hypermotility (achalasia) due to?
Due to loss of ganglion cells in aurebach’s myenteric plexus in LOS wall thus decreases activity of inhibitory NCNA neurones.
What are causes of secondary achalasia?
Chagas disease (trypanosomiasis), protozoa infection, amyloid/sarcoma/eosinophilic oesophagitis
What is pathophysiology of hypermotility (achalasia)? What does it lead to?
Decreased activity of inhibitory NCNA neurones so increased resting LOS pressure. Receptive relaxation happens too late and is too weak. Because pressure in LOS a lot higher than stomach pressure, swallowed food collects in oesophagus causing increased pressure throughout with dilation of oesophgaus. Loss of peristalsis in distal oesophagus because LOS constricted so food cant pass. Resultant dysphagia, regurgitation, oesophgaitis, weight loss, possible pneumonia due to aspirating oesophageal contents.
What is the disease course of hypermotility (achlasia) and what happens if untreated? Risks?
Insidious, symptoms gradually worsen over years. Untreated can lead to progressive oesophageal dilatation. Risk of oesophgeal cancer high.
What are treatments for achalasia and what do they involve?
- pneumatic dilatation (PD): weakens LOS by by stretching and inflating it. Efficacious but many relapse. Surgical –> 1. heller’s myotomy: continous myotomy on oesophagus and stomach 2. dor fundoplication: anterior fundus sutured to distal oesophagus. Risks - oesophgeal/gastric perforation, division of vagus nerves, splenic injury.
What is hypomotility (scleroderma)? What does it cause? What is it often assoicated with?
Scleroderma is autoimmune disease. Neuronal defects cause atrophy of smooth muscle of oesophagus, peristalsis in distal portion stops, decreasing resting pressure of LOS. Get GORD as a result. Associated with CREST syndrome.
What is treatment for hypomotility (scleroderma)?
Exclude organic obstruction (malignnacy), give prokinetics to improve peristalsis (cisapride) but not very effective (usually peristaltic failure irreversible)
What is disordered coordination of oesophagus and what does it cause?
Disordered coordination of oesophgeal contractions lead to dysphagia and chest pain. Very high pressures of 400-500mmHg. Marked hypertrophy of circular muscle
Why do we see corkscrew oesophagus on barium in disordered coordination?
Marked hypertrophy of circular muscle in oesophagus so corkscrew oesophagus
Treatment for corkscrew oesophagus?
May respond to forceful PD of cardia (pneumatic dilatation but response unpredictable)