Oesophagus Disorders Flashcards
1
Q
Anatomy of oesophagus?
A
- Fibromuscular tube (25cm) of striated squamous epithelium
- Posterior to trachea
- Begins at end of laryngopharynx
- Joins stomach a few cm from diaphragm (at cardiac orifice)
- Extends from lower border of cricoid cartilage (C6) to cardiac orifice of stomach (T12)
2
Q
Composition of oesophagus wall?
A
striated muscle in upper part
smooth muscle in lower part
mixture in middle
LOS both squamous + columnar epithelium coexist
3
Q
Role of oesophagus?
A
- Transports food to stomach
- Secretes mucus
- Swallowing (deglutition)
4
Q
What promotes transport of ingested food into stomach?
A
Relaxation of sphincters (UOS + LOS) which involves contraction + relaxation of oesophagus which transports food via GIT
5
Q
Describe how food reaches stomach
A
- swallows food down throat
- food approaches upper oesophageal sphincter
- opens so food/bolus can enter oesophagus
- rhythmic waves of muscular contractions + relaxations = peristalsis propel food downward
- food passes via lower oesophageal sphincter
- into stomach (reservoir)
6
Q
Muscle structure of oesophagus?
A
- Skeletal muscles surrounds oesophagus below pharynx (1/3)
- Smooth muscles surround lower (2/3)
7
Q
Structure of upper oesophageal sphincter (UOS)?
A
- Striated muscle
- Musculo-cartilaginous structure
- Composed of posterior surface of thyroid cartilage, cricoid cartilage, hyoid bone, cricopharyngeus, thyropharyngeus, cranial cervical oesophagus muscles
- 3 muscles spread upwards, posteriorly, insert into oesophageal submucosa after crossing muscle bundles of opposite side
- Thyrophrangeus = obliquely oriented
- Cricophrayngeus = transversely oriented
- Between 2 muscles = zone of sparse musculature – Killian Triangle forms, Zenker’s diverticulum might emerge
8
Q
Role of UOS?
A
- Area of high pressure zone between pharynx + cervical oesophagus
- Constricted to avoid air entering oesophagus
9
Q
Structure of lower oesophageal sphincter (LOS)?
A
smooth muscle
10
Q
Role of LOS?
A
-Acts as flap valve
-Area of high pressure zone located where oesophagus merges with stomach
-Has intrinsic + extrinsic components :
intrinsic = oesophageal muscles under neurohormonal influence
extrinsic = diaphragm muscle (adjunctive external sphincter)
11
Q
Effect of malfunction of intrinsic and extrinsic components of LOS?
A
GORD
12
Q
Muscle arrangment of oesephagus?
A
- Inner circular + outer longitudinal muscles
- Upper part = striated
- Middle third = gradual transition from striated to smooth
- Lower end = smooth muscle
Killian’s triangle →Zenker’s diverticulum
13
Q
Role of pharyngeal raphe?
A
raphe that’s origin + insertion for pharyngeal constrictors (thyropharyngeal part of inferior, middle, superior pharyngeal constrictor muscle)
14
Q
Define raphe + eg?
A
a groove, ridge, or seam in an organ or tissue marking line where 2 halves fused in embryo
eg connecting ridge between 2 halves of medulla oblongata or tegmentum of midbrain
15
Q
Control of function of UOS?
A
Afferent inputs to motor neurons
16
Q
Reflexes lead to?
A
Contraction/relaxation
17
Q
What’s Sellick manoeuvre?
A
=when anaesthetics press on cricoid cartilage during
endotracheal intubation to prevent gastric reflux
Intubate: put tube in, commonly used to refer to insertion of breathing tube into trachea for mechanical ventilation
18
Q
Weak spot of thyropharyngeus + cricopharyngeus muscles?
A
Pharyngeal diverticulum
19
Q
Role of cricoid cartilage?
A
provides attachment points for cricothyroid muscle, posterior + lateral cricoarytenoid muscles, ligaments vital for opening/closing airways + speech
20
Q
What are efferent nerves?
A
motor nerves that communicate need for action on part of organs or muscles to maintain efficiency of body
21
Q
How cervical oesophagus runs?
A
- Begins at lower end of pharynx (C6 or lower border of cricoid cartilage)
- Extends to thoracic inlet (suprasternal notch); 18 cm from upper incisors
22
Q
Features of thyroid cartilage?
A
- Largest of 9 cartilages of laryngeal skeleton
- Doesn’t encircle larynx in full (cricoid cartilage encircles larynx)
23
Q
How does trachea run?
A
- Anterior to oesophagus
- Connected to oesophagus by loose connective tissue
- Connects pharynx to stomach
- Begins in neck at pharyngo-oesophageal junction (C5-C6 vertebral interspace at inferior border of cricoid cartilage)
- Descends anteriorly to vertebral column via superior + inferior mediasternum
24
Q
Define dehiscence
A
splitting at maturity along a built-in line of weakness in a plant structure to release its contents
involve complete detachment of a part, structures that open like this are dehiscent
25
Intrinsic components of LOS?
-Thick circular smooth muscle layers
-Clasp-like semicircular smooth muscle fibres (encircle gastroesophageal junction medially) on right side : myogenic activity (some resting tone), but less ACh-responsive
-Oblique gastric muscle fibres on left lateral side :
prevent regurgitation (responsive to cholinergic innervation)
26
Why's reflux common in infants?
oblique angle underdeveloped in infants, oesophagus makes a vertical junction with stomach
27
What's myogenic?
contractions initiated by cells within (myocytes) so no nerve innervation required for contraction
28
What's angle of his (oblique angle)?
-Acute angle created between entrance to stomach (cardia), oesophagus
29
Role of angle of his (oblique angle)?
Forms a valve = preventing reflux of duodenal bile, enzymes, gastric acid from entering oesophagus so no irritation of oesophageal lining, inflammation, Barrett's oesophagus
30
Extrinsic components of LOS?
-Crural diaphragm encircles LOS:
forms channel so oesophagus enters abdomen
-Fibres of crural diaphragm has a “pinchcock-like” (clamp regulates flow of fluid via tube) action (extrinsic sphincter; diaphragmatic sphincter)- myogenic tone
31
Antireflux barriers?
- Sphincters : LOS diaphragmatic sphincter
| - Anatomic configuration at gastroesophageal junction (mucosal folds)
32
Role of diaphragm in LOS?
=extrinsic component LOS has diaphragm muscle
| -Adjunctive external sphincter raises pressure in terminal oesophagus related to movements of respiration
33
Role of crural diaphragm?
- Form oesophageal hiatus
- Encircles proximal 2-4cm of LOS
- Determines inspiratory-spike-like increase in LOS pressure as measured by oesophageal manometry
34
What's oesophageal opening created by?
loop of right crux of diaphragm
35
Innervation of oesophagus?
Cholinergic (via ACh)
| Non-cholinergic, NANC in control of tone of LOS
36
What causes contraction of intrinsic sphincters?
Ach, SP
37
What causes relaxation of intrinsic sphincters?
NO + VIP
38
Describe how NO causes relaxation of smooth muscle cells
- NO interacts with AC
- converts GTP -> cGMP
- cGMP activates PKG
- PKG acts on myosin phosphatase on smooth muscle cells
- causes smooth muscle relaxation
is an enzyme which. The
39
Role of myosin phosphatase?
- dephosphorylates regulatory chain of myosin II
- occurs in smooth muscles
- initiates relaxation
- so myosin phosphatase undoes muscle contraction process initiated by initiated by myosin light-chain kinase
40
What's upper part of oesophagus innervated by?
striated muscle
somatic motor neurons of vagus w/o interruption
-Vagus nerve
-Splanchnic nerves (thoracic sympathetic trunks)
41
What's lower part of oesophagus innervated by?
smooth muscles
visceral motor neurons of vagus with interruptions (synapse with postganglionic neurons; cell bodies in oesophagus, splanchnic plexus)
42
What's oesophageal plexus?
encircles oesophagus
43
What are somatic motor neurons?
alpha, beta, gamma efferent neurons (muscle contraction)
| alpha motor neurons = innervate skeletal muscle + cause muscle contractions that generate movement
44
Define viscera
internal organs in main cavities of body eg intestines.
45
What are splanchnic nerves?
- Paired visceral nerves (contribute to innervation of internal organs)
- Carry sensory fibres from organs (visceral afferent fibres) + ANS fibres (visceral efferent fibres)
- Carry sympathetic fibres except pelvic splanchnic nerves which carry para fibres
46
Where do integration of impulses occur?
nucleus of tractus solitarius (NTS), nucleus ambiguus (NA), dorsal vagal nucleus
47
Features of dorsal vagal nucleus?
- Of vagus nerve or posterior motor nucleus of vagus
- Cranial nerve nucleus for vagus nerve in medulla
- Lies under floor of 4th ventricle
- Serves para vagal functions in GIT, lungs, other thoracic + abdominal vagal innervations.
48
Role of nucleus ambiguus?
contain cell bodies for preganglionic para vagal neurons that innervate the heart reside
49
How phrenic nerve passes?
- originates from the 4th cervical nerve, but also receives contributions from 5th + 3rd cervical nerves (C3-C5) so receives innervation from parts of both cervical plexus + brachial plexus of nerves
- passes down between lung + heart
- reaches diaphragm
50
Role of phrenic nerve?
- Breathing
- Innervates external, internal intercostal muscles, diaphragm
- Passes motor info to diaphragm
- Receives sensory info fro diaphragm
- Contain motor, sensory, sympathetic nerve fibres
- Provide only motor supply to diaphragm
- Provide sensation to central tendon
- Supplies mediastinal pleura + pericardium
51
Describe swallow reflex
- excitation of receptors in pharynx (oesophageal peristalsis + relaxation)
- afferent stimulus travels to nucleus solitarius
- set of events from dorsal vagal nucleus, nucleus ambiguus mediates oesophageal peristalsis + sphincter relaxation
- efferent impulses pass to pharyngeal musculature + tongue
- vagal efferent fibres communicate with myenteric neurons
- mediates relaxation of LOS
52
eg of postganglionic transmitters
NO, VIP
53
What's contraction of crural diaphragm controlled by?
inspiratory centre in brainstem + nucleus of phrenic nerve
54
What's crural diaphragm innervated by
right + left phrenic nerves via ACh
55
Describe reflux reflex
- transient lower oesophageal sphincter relaxation, the principal mechanism of reflux uses same efferent neural pathway as swallow reflex.
- origin of afferent signals for transient lower oesophageal sphincter relaxation in pharynx, larynx, or stomach
- efferent pathway is in vagus nerve
- NO = postganglionic neurotransmitter relaxes LOS
56
Afferent impulses that triggers swallowing?
in trigeminal, glossopharyngeal, vagus nerves
57
Efferent impulses from swallowing?
pass to pharyngeal musculature + tongue
58
Features of trigeminal nerve?
CN 5
Sensation in face
1 on each side of pons with 3 major bundles:
-ophthalmic nerve (V1)
-maxillary nerve (V2)
-mandibullary nerve (V3) for motor functions - chewing, biting
59
Role of glossopharyngeal nerve?
- Branch to tongue
- Taste + general sensation
- Serve carotid body, carotid sinus, parotid gland (major salivary gland), palatine tonsils (tonsils on left and right side of back of throat)
60
Features of nucleus of tractus solitarius?
=brainstem nucleus on each side of upper medulla
- Lies lateral to dorsal nucleus of vagus
- Has many connecting neurons
- Medial to spinal tract + nucleus of trigeminal nerve
- Has afferent fibres extending inferiorly within upper medulla as the tract of solitarius
61
What initiates swallowing?
- Voluntary – collect material on tongue + push backwards into pharynx (skeletal muscle, mucus membrane)
- Waves of involuntary contractions push material into oesophagus
mouth→oropharynx→laryngopharynx→oesophagus
62
Reflex responses when swallowing?
- Inhibition of respiration (breathing)- nasopharynx closed off
- Closure of glottis (around vocal cords) by epiglottis (prevents food from entering trachea)
- Ring of peristaltic waves (4cm/s) behind food move it towards stomach (primary peristalsis)
- 2nd wave of peristalsis moves food remnants along (secondary peristalsis)
- Coordinated opening + closing of upper, lower sphincters
63
What's primary peristalsis?
Ring of peristaltic waves (4cm/s) behind food move it towards stomach
64
What's secondary peristalsis?
2nd wave of peristalsis moves food remnants along
65
Where's swallowing centre?
brain stem; sensory + cortical input with respect to swallowing integrated in NTS + NA
66
What moves food towards stomach + along GIT?
Progressive muscular contractions + relaxations
67
Cause of oropharyngeal dysphagia?
Swallowing difficulty by inability of UOS to open or discoordination of timing between opening of UOS + pharyngeal push of ingested bolus
68
Describe secondary peristalsis
- relaxation of UOS so food passes
- UOS closes as soon as food passes
- glottis opens
- breathing resumes
- LOS opens + stays open throughout swallowing
- LOS closes after material passed
- large food material doesn't reach stomach after 1st peristaltic wave
- food distenses oesophagus lumen stimulating receptors
- repeated waves of peristalsis (secondary peristalsis)
69
What prevents reflux of gastric contents?
- LOS closes after material passed
- “Pinchcock” effect of diaphragmatic sphincter on lower oesophagus
- Plug-like action of mucosal folds in cardia which occludes lumen of gastro-oesophageal junction:
* abdominal pressure acting on intra-abdominal parts of oesophagus
* valve-like effect of oblique entry of oesophagus into stomach in adults
70
Where's anti-reflux barrier?
region of gastro-oesophageal junction where transition from smooth muscles that line oesophagus to rugal folds (wrinkles or gastric folds)
71
When does gastro-oesophageal junction must maintain competence?
- At rest
| - Raised intra abdominal pressure
72
What happens if gastro-oesophageal sphincter becomes incompetent?
GORD
73
Describe transition from smooth oesophageal lining to rugal folds
- empty state = mucosa + submucosa thrown into folds
| - distended = folds “ironed out” + flat
74
What's Collar of Helvitius (or loop of Willus)?
where circular muscular fibres of the oesophagus join oblique fibres of stomach
75
What's zigzag line (Z-line)?
squamocolumnar mucosal junction between oesophagus + stomach – invisible radiologically
76
Role of mucous cells?
secrete an alkaline mucus that protects epithelium against shear stress + acid
77
Role of parietal cells?
secrete HCl aicd
78
Role of chief cells?
secrete pepsin, a proteolytic enzyme
79
Role of G cells?
secrete gastrin hormone
80
Types of secretory epithelial cells that cover stomach surface + extend down into gastric pits + glands?
mucous, parietal, chief, G cells
81
SUMMARY
- Anti-reflux barriers stop reflux of gastric contents into the oesophagus
- Anti-reflux barriers: LOS, diaphragmatic sphincter, gastro-oesophageal junction
- Both sphincters maintain tonic closure of sphincter + relax upon swallowing, but can also relax w/o swallow, because transient spontaneous relaxation reflex (TSR) of LOS
- LOS: smooth muscles; myogenic (tonic contraction), neurogenic properties; vagal innervation (NO, VIP)
- Diaphragmatic sphincter: striated muscles that exhibit tone + contract due to excitatory nerves
- Swallowing + TSR of LOS relax diaphragm
- Loss of inhibitory mechanisms of sphincters --> achalasia
- Dysfunctional anti-reflux barriers →GORD or dysphagia
- Increased frequency of TSR of LOS → GORD
82
Types of oesophageal disorders?
- Achalasia : Disorders of motility or peristalsis of oesophagus (assess the motor function of UOS, LOS, oesophageal body)
- GORD: Reflux of stomach acids into oesophagus; regurgitation (weak LOS)
- Aphagia: Swallowing difficulty must determine the cause
- Oesophageal spasm: Abnormal oesophageal contractions + food is ineffectively reaching stomach
- Diffuse oesophageal spasm: Chest pain coming from oesophagus (~angina)
83
What's achalasia?
- Failure to relax (disease of muscle of oesophagus; causes swallowing difficulties)
- Oesophageal motor disorder characterised by increased LOS pressure, diminished to absent peristalsis in distal oesophagus composed of smooth muscle, lack of a coordinated LOS relaxation in response to swallowing
84
Pathophysiology of achalasia?
- 1/100,000 presents at any age
- Impaired LOS relaxation;
- Accompanied by impaired peristalsis;
- Food + liquids fail to reach stomach --> dilation of lower oesophagus;
- Long period of sporadic dysphagia
- Regurgitation of food
85
Aetiology of achalasia?
- Disorders of motility or peristalsis of oesophagus (assess motor function of UOS, LOS, oesophageal body)
- Damage to innervation of oesophagus
- Degenerative lesions to vagus + loss of myenteric plexus ganglionic cells in oesophagus
- Initiating factor unknown - autoimmune or triggered by infection
86
Effect of loss of ganglionic cells in oesophagus mesenteric plexus?
-Vital inhibitory neurons induce LOS relaxation + coordinate proximal-to-distal peristaltic contraction of oesophagus
In Achalasia lack of coordination of contraction + relaxation of LOS
87
Role of myenteric plexus?
major nerve supply to GIT + controls motility
88
Development of achalasia?
- genetic predisposition
- eg HLA (human leukocyte antigen) class II susceptibility, gene mutations, certain SNPs (single nucleotide polymorphism) have a viral trigger (herpes simplex virus 1, varicella zoster, measles)
- aggressive inflammatory response
- interactions between T-cell–mediated inflammatory infiltrate, extracellular matrix turnover proteins, development of humoral response (myenteric antibodies)
- apoptosis of ganglionic neurons
- myenteric plexitis + fibrosis
- impaired relaxation of LOS + no oesophageal peristalsis
89
Symptoms of achalasia?
- Dysphagia = difficult or painful swallowing (solids + liquids) since LOS fails to relax enough to allow food to be emptied into stomach; poor peristalsis
- Vomiting/regurgitation
- Weight loss = failure to thrive
- Heartburn =
* retrosternal burning sensation due to oesophageal dysmotility
* retention of ingested (acidic) food
* generation of lactic acid from decomposition of retained food
* retention of acid reflux in oesophagus due to poor emptying + incomplete relaxation of LOS
90
Diagnosis of achalasia?
1) Barium radiography (barium swallow): dilatation of oesophagus with beak deformity at lower end + evaluate entire swallowing channel (mouth, pharynx, oesophagus)
2) Oesophageal manometry: absent peristalsis
91
Why do a oesophageal manometry?
- Determine cause of non-cardiac chest pain
- Evaluate cause of reflux (regurgitation) of stomach acid (GORD?)
- Determine cause of dysphagia (does UOS/LOS contract + relax properly?)
- Allows evaluation of strength of coordination of muscle contractions
- Relaxation function of LOS enable food to enter stomach
Overall if oesophagus contracting + relaxing properly
92
Define aphagia
inability or refusal to swallow
93
Normal results of oesophageal manometry?
- Normal LOS pressure = 15mmHg but when swallowing, less than 10 mm Hg – as it relaxes to let food pass into stomach
- LOS pressure <26 mmHg + normal muscle contractions upon swallowing
- Pressure of muscle contractions moving food down oesophagus is normal
- Muscle contractions follow normal pattern down oesophagus
94
GORD results of oesophageal manometry?
Low LOS pressure suggests GORD, but note that GORD can occur in individuals with normal LOS pressure
95
High results of oesophageal manometry?
>100 mm Hg is achalasia
| > 200 mm Hg is nut cracker achalasia
96
What type of disease is achalasia + diff types?
- Heterogeneous disease
- 3 distinct types based on manometric patterns
- Type I (classic) = minimal contractility in oesophageal body
- Type II = intermittent periods of panesophageal pressurisation
- Type III (spastic) = premature or spastic distal oesophageal contractions
97
Abnormal results of oesophageal manometry show/are characterised by?
- Presence of muscle spasms in oesophageal body so increased tone
- Achalasia = high LOS pressure which fails to relax after swallowing
- Weak contractions along length of oesophagus
98
Effect of loss of inhibitory neurons secreting VIP + NO?
unopposed excitatory activity + failure of LOS relaxation.
99
Procedure of oesophageal manometry?
- spray local anaesthetic/apply a numbing gel (no sedation)
- lubricated pressure-sensitive tube (catheter) inserted into nostril→ throat → oesophagus→ stomach
- take deep breath + swallow water
- measure strength + coordination of muscle contractions
- evaluates strength + relaxation function of LOS
- slowly remove catheter
- data helps determine where in oesophagus to place pH probe
100
Characteristic manometric findings?
-LOS fails to relax upon wet swallow (<75% relaxation)
-Pressure of LOS :
<26 mm Hg is normal
>100 is achalasia
> 200 is nut cracker achalasia.
-Aperistalsis in oesophageal body
-Relative increase in intra-oesophageal pressure as compared with intra-gastric pressure
101
Role of calcium channel blockers used in achalasia + eg?
relax the oesophageal sphincter
| nifedipine, verapamil
102
Why surgical myotomy?
provides best long term control of symptoms
103
Why laparoscopic myotomy used in achalasia?
initial treatment for most individuals with achalasia
104
Why is old age a favourable predictor for pneumatic dilation?
- LOS has 2 components:
* clasp fibres encircling gastroesophageal junction medially
* gastric sling fibres on left lateral side
- in PD, only clasp fibres targeted so gastric sling fibres remain unaffected so contribute to residual LOS tone
- tone higher in younger patients
- Patients with long-standing symptoms have mild improvement in oesophageal emptying as dramatic relief from dysphagia
- Perceive less pain compared to younger when balloon distended in oesophagus
- Expected to have weaker LOS muscles that might be easily torn during PD
105
Why Is pneumatic dilation less effective in younger men?
- LOS muscles stronger among men
| - Higher LOS tone in younger men
106
Why endoscopic balloon dilation of LOS or surgery for achalasia?
weaken sphincter
107
Why heller’s myotomy used for achalasia?
laparoscopic (minimally invasive) surgical procedure used to treat achalasia
108
Why botulinum toxin used in achalasia?
- neurotoxic protein from Clostridium botulinum
- blocks cholinergic nerve endings (stops ACh release) in ANS
- Well tolerated, safe, efficacious
- But PD superior to botulinum toxin
109
What's reflux?
Retro-grade movement of gastric content into oesophagus due to relaxation of LOS - brief, relatively infrequent occuring after meals in normal individuals (transient spontaneous LOS relaxation)
110
Why does salivia come from reflux?
- stimulates salivia
- saliva is an effective natural antacid
- dilutes + neutralises refluxed gastric contents
111
Effet of low rate of salivation?
- lack of ability to swallow own saliva
- prolongation of contact of refluxed material with oesophagus
- oesophageal irritation + oesophageal damage
- gastro-oesophageal reflux disease (GORD)
112
What's gastro-oesophageal reflux disease (GORD)?
- Retro-grade movement of gastric content into oesophagus due to relaxation of the LOS --> burning sensation in chest after meals – angina-like pain
- When reflux more frequent + troublesome
113
Causes of reflux in those with GORD?
-Transient spontaneous LOS relaxation (TSR)
98% of reflux events associated with TSR LOS
60% in patients (40% from malfunction of extrinsic + intrinsic of LOS)
-Resting LOS pressure too weak to resist pressure within stomach
-Sudden relaxation of LOS that's not induced by swallowing
114
What's intrinsic component
Thick circular muscle layers of oesophagus :
- clasp-like semicircular smooth muscles (↑myogenic activity, less ACh responsive)
- sling-like oblique fibres (little resting tone, ACh-responsive)
115
Features of pneumatic dilation?
- Effective alternative to surgery
- Response to PD depends on age, gender, size of the balloon
- Long-term response predicted with help of post-PD manometry + timed barium oesophagogram
- Balloon size chosen according to gender
- Performed with diff dilators of variable balloon compliances eg low compliance polyethylene pneumatic dilator (Rigiflex dilator)
116
Features of transient spontaneous relaxation reflex (TSR) of LOS?
- pathway for TSR of LOS is vagal reflex pathway
- triggered by gastric distention or pharyngeal stimulus + integration that occurs in brainstem
- threshold for triggering TSR lowered by concurrent stimulation of pharynx (+ larynx)
- threshold increased by supine posture
117
Factors that contribute to severity of GORD?
- Weak or uncoordinated oesophageal contractions
- Time oesophagus exposed to gastric acid
- ↑Gastric acid secretion + bile in gastric contents
- Pressure placed on anti-reflux barrier
- Impaired gastric emptying alone --> severe GORD
118
When does reflux occur?
after eating, lying down (supine), delayed gastric emptying
119
Overall, GORD is caused by?
Reflux of gastric contents through the LOS (acid or bile)
Chronic oesophagitis (erosive or non-erosive)
Prevalence: 30%
120
Factors associated with GORD?
Pregnancy
Obesity
Fat, chocolate, coffee, alcohol ingestion
Large meals, tomatoes, orange juice, onions,
Cigarette
Drugs (eg anticholinergic agents, calcium channel blockers, nitrate drugs)
121
Describe complications of GORD?
- Oesophagus has squamous mucosa
- acid reflux
- desquamation of oesophageal cells (injury of squamous mucosa)
- ↑cell loss
- basal cell hyperplasia
- excessive desquamation → ulceration
- ulcers haemorrhage, perforate, heal by fibrosis with strictures
- Barrett’s oesophagus + oesophageal cancer
122
Pathophysiology of GORD?
- Resting LOS tone is low or absent
- LOS tone fails to increase when lying flat or during pregnancy
- Poor oesophageal peristalsis so ↓ clearance of acid
- Hiatus hernia impairs LOS + diaphragm closing mechanisms
- Delayed gastric emptying
123
Symptoms of GORD?
Heartburn and acid regurgitation
Wake up at night – reflux irritates the larynx
Dysphagia
124
Investigating GORD?
- Low dose proton pump inhibitor (PPI) challenge is 1st line
- Upper GI endoscopy
- Manometry
- 24hr ambulatory pH monitoring
125
Findings from continuous pH monitoring?
Normal reflux on a daily basis so GORD implies presence of excess reflux + heartburn doesn't improve when lying down
126
Pregnancy + GORD?
- Foetus increases pressure on abdominal contents + pushes terminal segments of oesophagus into thoracic cavity
- Last trimester of pregnancy associated with increased abdominal pressure + forces gastric contents into oesophagus
- Heartburn subsides in last months of pregnancy as uterus descends into pelvis
127
Describe heartburn after a large meal
- eating large meals
- less efficient LOS
- gastric contents episodically refluxed into oesophagus
- heartburn
- ulcer, scarring, obstruction, perforation of lower oesophagus
128
Potential long term effects of GORD?
- Oesophagitis, oesophageal strictures
- Squamous cell carcinoma
- Barrett's syndrome-predispose someone to oesophageal adenocarcinoma
- Oesophageal ulcer
129
When's manometry ordered?
Symptoms of:
- heartburn or nausea after eating (GORD)
- problems swallowing (feeling that food is stuck behind breast bone - achalasia)
130
Management + drug treatment of GORD?
- Life-style changes - raise head of bed at night, weight loss, modify food
- ↓Foods + drink which cause symptoms
- Laparoscopic anti-reflux surgery (Nissen fundoplication – wrap fundus around LOS strengthening it + creates valve mechanism)
- Take antacids
- Take H2 receptor antagonists + proton pump inhibitors
- Take metoclopramide/domperidone enhancing peristalsis + help gastric acid clearance
- Fundoplication causes dysphagia as it reduces distensibility of LOS
131
Lifestyle changes that alleviate symptoms of GORD?
- Avoid large meals : increase likelihood of increased gastric (stomach) pressure + reflux
- Lose weight
- Avoid foods that increase gastric acidity
- Avoid foods that slow gastric emptying
- Avoid lying down after meals - elevate head of bed
- Avoid some drugs + smoking
- Decease fat intake : decrease LES pressure + delay stomach emptying --> increasing risk of reflux
- Avoid chocolate : contains methylxanthine, which reduces LES pressure by causing relaxation of smooth muscle
- Avoid coffee : promote gastroesophageal reflux
132
Role of antacids in GORD?
- Neutralise gastric acid; ↑ pH of gastric lumen
| - Inhibit peptic activity + stop acid secretion
133
Features of anatcids?
- Magnesium salts→ diarrhoea
- Aluminium salts→ constipation
- Use mixture of 2 to ensure bowel function
- Combine alginates eg gaviscon with antacids for oesophageal reflux
- Alginic acid + saliva form a raft which floats on content of gastric lumen + protects oesophageal mucosa from reflux
- ↓acid secretion + heal ulcer, but removal of H. pylori is vital to stop ulcer returning.
