Oesophagus Flashcards
Types of Achalsia
Type 1 (classic): absence of any contractions or pan-oesophageal pressurisations that fail to reach 30mmHg. Type 2 (most): pan-oesophageal pressurisations that occur in ≥20% of swallows, reaching ≥30mmHg. These are due to residual contractile activity in both circular and longitudinal muscles Type 3 = spastic activity, shortened latency =\> premature/spastic contraction
T score Oesaphgeal Cancer
T-factor
- Tis: carcinoma in situ, high-grade dysplasia
- T1: invades lamina propria or submucosa
o T1a: lamina propria or muscularis mucosa
o T1b: submucosa
- T2: Invades muscularis propria
- T3: invades adventitia
- T4: invades adjacent structures
o T4a: resectable tumour invading pleura, pericardium, azygous vein, diaphragm, peritoneum
o T4b: unresectable tumour invading other structures (aorta, vertebrae, airway)
N/ M score Oesophageal Cancer
● N-factor (at least 6 nodes should be assessed)
- N0: no regional LN mets
- N1:mets in 1-2 regional LNs
- N2:mets in 3-6 regional LNs
- N3:mets in 7+ regional lymph nodes
● M factor
- M0: no distant mets
- M1: distant mets (most common = liver, lung, bone, adrenal)
Management of Patients with metastatic oesophageal cancer
o combination chemo e.g. FOLFOX (leucovorin, 5FU, oxaliplatin) as first line o HER2 assay for consideration of trastuzumab (herceptin)
o enroll in clinical trial
o tumours with dMMR, MSI-H, or overexpression of programmed cell death
ligand 1 (PD-L1) is immunotherapy with an immune checkpoint inhibitor e.g.
pembrulizumab or VEGF inhibitor (ramucirumab)
o If not fit => supportive mx and palliation
Oesophageal Embryology
Develops as part of the foregut from the endodermal primitive gut tube.
The gut tube forms during weeks 6-8 (abnormalities lead to atresia or stenosis.
The region of the foregut just caudal to the pharynx develops two longitudinal ridges called the tracheoesophageal folds that divide the tube ventrally into the trachea (and subsequent lung buds), and dorsally into the oesophagus.
As with the rest of the gut tube, the lumen of the oesophagus becomes temporarily OCCLUDED around the 5th week of development and recanalises by around the 9th week.
The oesophagus is initially short and must grow in length to “keep up” with the overall growth in length of the embryo The heart and lungs descend with the oesophageal lengthening and reach their final position at week 7
Clinical consideration of oesophageal embryology?
Oesophageal atresia
○ occurs when the tracheoesophageal ridges deviate too far dorsally causing the upper oesophagus to end as a closed tube.
○ usually is accompanied by a tracheoesophageal fistula, in which case gut contents can be aspirated into the lungs after birth causing inflammation (pneumonitis) or even infection (pneumonia).
○ typically associated with polyhydramnios prenatally (the fetus cannot swallow amniotic fluid and it accumulates in the amniotic cavity). Postnatally, the child will regurgitate IMMEDIATELY upon feeding and, if a tracheoesophageal fistula is present, there will be congestion in the lungs.
Oesophageal stenosis
○ occurs when the oesophagus fails to recanalise (week 7)
○ also typically associated with polyhydramnios prenatally. Postnatally, the child will regurgitate IMMEDIATELY upon feeding. However, there is usually NOT a tracheoesophageal fistula, so the lungs will usually NOT be congested.
Congenital hiatal hernia
○ occurs when the oesophagus fails to grow adequately in length. As a result, the oesophagus is too short and therefore pulls the cardiac stomach into the oesophageal hiatus in the diaphragm. The resulting compromised structure of the hiatus can allow gut contents (usually loops of small bowel) to herniate up into the thoracic cavity.
Oesophageal Anatomy
Describe the anatomy and relations of the oesophagus
- The oesophagus is a muscular tube between the cricoid (C6) superiorly and the gastric cardia inferiorly. It measures 25 cm in length. It passes through the oesophageal hiatus at T10. During its descent it inclines initially to the left, returns to the midline, then deviates left again to sit 2.5cm to the left of the midline on entry to the abdomen. Its lumen is indented at 4 points; its origin by cricopharyngeus (15cm from incisors), by the aorta (22cm from incisors), and by the left main bronchus (27cm from incisors) – also described as the bronchoaorticconstriction- and finally at the diaphragmatic hiatus (38cm from incisors). It is* often described as having 3 parts: the cervical, thoracic, and abdominal oesophagus. The intra-abdominal part of the oesophagus is only 1-2cm in length.
- Posteriorly it is related to the trachea until the trachea bifurcates at T4. At the same point, the azygous is to its right and the aortic arch to its left and the thoracic duct crosses from the right to the left side of the oesophagus. Between the tracheal bifurcation and the diaphragm the left atrium is the anterior relation. On either side the mediastinal pleura touches the oesophagus.*
Oesophageal Blood supply?
Inferior thyroid (cervical)
Aortic branches (thoracic)
Left Gastric (abdominal)
Arterial supply is via branches of the _inferior thyroid artery_ superiorly, direct _aortic branches_ in its mid-portion, and from ascending oesophageal branches from the _left gastric_ distally. Venous drainage corresponds to arterial supply, _importantly the left gastric-ascending oesophageal veins are a site of porto-systemic shunt and possible varices_.
- Lymphatic drainage is via a rich submucosal plexus throughout its length; the oesophagus may drain to the cervical, mediastinal, or coeliac lymphatic plexuses.*
- Nerve supply is segmental; its upper portion is supplied by the recurrent laryngeal nerves, the vagus and thoracic splanchnics supply autonomic nerves for the remainder.*
Epithelium??
Muscularis?
Stratified squamous, cuboidal at GOJ
Striated proximally, mixed mid, smooth distally.
Thicks muscular mucosal + no adventitia/serosa - therefore join to this
Oesophageal nerve supply
PARASYMPATHETIC - VAGUS
Sympathetic - middle cervical ganglion (proximal) + upper 4 ganglia (distal)
GOJ: What contributes to the anti reflux barriers
- The intrinsic musculature of the distal oesophagus is in a state of tonic contraction - relax after swallowing to allow the passage of food/liquid
- Sling fibres of the gastric cardia are oriented diagonally from the cardia funds junction to the lesser curve of the stomach (insert into submucosa) → located same anatomic depth as the circular muscles of oesophagus
- The crura of the diaphragm surrounds the oesophagus - compressed the oesophagus during inspiration
- Increased intra-ado pressure transmitter to GOJ which increases the pressure in the distal oesophgus
- Normal pressure gradient between the stomach and the oesophagus. The oesophagus is -5mm and the stomach is +5mmhg
- Neurological control of the lower oesophageal sphincter.
Central – dorsal efferents-> vagal efferents (sensory via tractus solitarus, neurotransmitters include glutamate, adrenaline, dopamine, acetylcholine and nitric oxide).
Peripheral – vagus fibres synapse in the myenteric plexus using Ach
Inhibitory control via nitric oxide and the interstitial cells of cajal
Physiology of swallowing??
Relaxation of upper and lower oesophageal sphincters
Food bolus is propelled by peristaltic wave due to sequential oesophageal muscle segmental contraction
- Primary peristalsis initiated centrally after swallowing: Wave starts in pharynx
o Initiated centrally (via vagus) - Nucleus ambiguous (skeletal muscle) + Dorsomotor complex (smooth muscle)
o Modified peripherally (local myogenic mechanisms)→ Affected by temperature, volume, acidity. Warm boluses exaggerate peristaltic wave
Secondary peristaltic wave
o Persistent bolus triggers local mechanisms by distending oesophagus
Tertiary contractions - Aberrant + No role in peristalsis
Peristaltic wave can be interrupted by subsequent peristaltic wave. This allows multiple swallows for same bolus. First swallow peristaltic wave is aborted. Mediated by intrinsic nitric oxide inhibition
Factors leading to GORD?
- GOJ incompetence due to … increased transient LOS relaxation (65%), incompetent/hypotensive LOS (18%) and Anatomic disruption of the GOJ and HH (17%)
- Abnormal oesophageal motility/laxity (achalasia, scleroderma) - relfux peristalsis is induced by oesophageal acid receptors
- Gastric abnormality - gastro paresis, gastric outlet obstruction, acid hyper secretion
Other contributers to antireflux…
- Mucosal rosette
- Oesophageal clearance - reflux peristalsis when acid high (reduced in motility disorders/ scleroderma)
- tissue resistance
- preepithelial - buffer layer/saliva
- epithelial - tight junction, pH dependant cation channels, intracellular buffers, transmural electrochemical gradients
- post-epithelial - adapter perfusion and epithelial repair
What is GORD?
GORD is a disorder where gastric contents reflux into the oesophagus resulting in symptoms and/or mucosal damage.
It is a risk factor for oesophageal carcinoma
Extent of symptoms and mucosal injury is proportional to frequency of reflux, duration of acid exposure and caustic potency of refluxed fluids.
Objectives of Investigation in GORD?
- Confirm the diagnosis of GORD
- Look for complications
- Define the anatomy of the oesophagus
- Exclude a motility disorder
Indications for endoscopy in GORD
Severity of symptoms: >4weeks, persistent symptoms despite treatment, relapsing symptoms
Alarm symptoms: new onset age 40-50, dysphagia, odynophagia, persistent vomiting, anorexia, weight loss, anaemia, GI bleeding, first degree relative with cancer
Abnormal imaging
Los Angeles Classification
Grade A: 1 or more mucosal breaks <5mm in length
Grade B - 1 of more mucosal breaks > 5mm but not continuous between the tops of adjacent folds
Grade C - 1 or more mucosal breaks that is continuous between the tops of folds but not circumferential
Grade D - mucosal breaks involving > ¾ of the oesophagus circumference
What is the Gold standard for the investigation of GORD?
pH studies
Indications: refractory typical symptoms, atypical symptoms, motility disorder suspected
Atypical reflux symptoms or non erosive disease for whom antireflux surgery is being considered.
What parameters are generated by pH studies
- Number of episodes
- Episodes > 5mins
- Total reflux time
- Longest episode
- Upright and supine times
Reflux episodes start when the pH is less than 4 and ends when it is above 5
Pathogenesis of GORD
The development of gastroesophageal reflux disease (GORD) reflects an imbalance between injurious or symptom-eliciting factors (reflux events, acidity of refluxate, oesophageal hypersensitivity) and defensive factors (oesophageal acid clearance, mucosal integrity). The extent of mucosal injury is proportional to the frequency of reflux events, the duration of mucosal acidification, and the caustic potency of refluxed fluid
What is the DeMeester score?
% of total time pH is <4 in 24 hours
Positive if above 14.72 (a bit more than 3.5 hours)
What are the risk factors for Barrett’s Oesophagus
GORD symptoms of 5 years
Nocturnal reflux
FH, obesity, smoking
Demographics: older white males.
WHAT IS THE GOLD STANDARD FOR MOTOR FUNCTION?
Manometry
Measures: baseline sphincter pressure and length of oesophageal sphincter, contraction amplitude, pressure wave duration, peristaltic velocity, LOS function and position
Medical Management of GORD
- *Suggested approach**
- Usually start with an 8-week trial of PPI + general measures (scope if alarm symptoms) - If symptoms controlled -> stop
- If recurrence within 3 months -> continue medical Rx long-term + scope (needs to be off PPI prior to Dx H pylori)
- If recurrence after 3 months -> repeat 8-week trial + scope (needs to be off PPI prior to Dx H pylori)
- If any evidence of severe oesophagitis or barrett’s, continue long-term
- In pregnancy -> diet and lifestyle modification, antacids + sucralfate (antacids containing sodium bicarbonate and magnesium trisilicate should be avoided) -> fail to respond = H2B -> PPI
PPI MOA?
Binds irreversably to the hydrogen/potassium ATPase enzyme on gastric parietal cells and block the secretion of hydrogen ions.
GORD: Surgical indications and Aims
Indications:
- Chronic GORD and want to avoid lifelong medications
- Symptoms on medical management
- HH and GORD
AIMS: Restore the anatomy and function of the anti reflux barriers by reducing any hiatus hernia and GOJ into the abdomen and creating a competent LOS by fundoplication + tightening the oesophageal hiatus
What is Barrett’s Oesophagus
The adaptive replacement of the normal stratified squamous epithelium of the distal oesophagus with metaplastic columnar epithelium as a result fo sustained exposure to reflux.
The z-line is situated more that 1cm from the GOJ. If less than 3cm the short segment, if more then long segment.
2% prevalence
White dudes → white to african american 20:1, M:F 1.7:1
histopath: intestinal metaplasia = intestinal type crypts lined by goblet and columnar cells
Pathogenesis of Barrett’s
Develops as an adaptive response to cell loss secondary to chronic inflammation in the setting of GORD.
Clonal expansion of metaplastic cell population that can survive in low pH
Inflammation drives cycle of proliferation and accumulation of genetic defects - p53 and p16 in submucosal oesophageal glands + loss of e-CADHERIN
Leads to dysplasia adenocarcinoma sequence - high grade dysplasia has nuclear pleomorphism and loss of crypto architecture, low grade has loss of cell differentiation and loss of goblet cells. Carcinoma when invasion past basement membrane.
0.25% per year progress to cancer
Natural History of Low Grade dysplasia
Characterised by mild to moderate atypic, loss of cellular differentiation, crowded elongated and hyperchromatic cells, loss of goblet cells
Majority will regress. 0.5% per year progress to cancer
Natural History and Features of High grade dysplasia
15-59% progress. 4-8%/yr progress to cancer
(there is a 40% rate of occult cancer in resected specimens)
Severe atypia, loss of crypt architecture, nuclear pleomorphism, and increased mitoses.
Histopathology of nondysplastic Barrett’s esophagus (a, NDBE), low-grade dysplasia (b, LGD), high-grade dysplasia (c, HGD), and (d) cancer. Yellow arrow in a indicates goblet-cell-positive mucosa adjacent to the squamocolumnar junction. Goblet cells are the hallmark for the diagnosis of Barrett’s esophagus without dysplasia
Describe the Prague Criteria for Barretts Oesophagus?
Barrett’s on endoscopy - proximal displacement of the squamous-columnar epithelium, salmon pink columnar mucosa with tongue extensions proximally or columnar islands.
C and M criteria
C - extent of the circumferential involvement in comfort OGJ
M - maximal length (including tongues but not islands) in cm from the GOJ
What is the Seattle protocol?
Seattle protocol: biopsy of any mucosal irregularity and four quadrant biopsies every 2 cm including normal mucosa proximally, unless known or suspected dysplasia then four quadrant biopsies every 1 cm
Every 2 years
Management of Barretts
- Indefinite PPI
- Consider fundoplication
- Surveillance, recommendations vary according to presence of dysplasia
American Gastroenterology association
- Barretts without dysplasia-short repeat in 3-5, long 2-3
- indefinite - repeat after 8-12 weeks high dose PPI
- LG dysplasia: Repeat OGD with 4 quadrant bx every 1cm in 8-12 weeks after high dose PPI - if confirmed to be LGD => can either continue to survey every 6months with 4 quadrant bx every 1cm + high dose PPI or refer for endoscopic eradication(resection/ablation) or anti-reflux surgery. Surveillance 2yearly if regresses to non dysplasia on two consecutive examinations.
- HG dysplasia: Repeat OGD with 4 quadrant bx every 1cm in 8-12 weeks after high dose PPI if confirmed by 2nd expert pathologist needs endoscopic eradication
Treatment of High Grade Dysplasia in Barretts
Goal - removal of all dysplastic and metaplastic tissue
- Endoscopic resection of an =visible mucosal irregularities prior to ablation. If specimen shows invasion of submucosa requires oesophagectomy. If mucosal - RFA (radiofrequency ablation) remainder of disease.
- Oesophagectomy (5yr survival 90%) only therapy that removes all neoplastic epithelium + occult malignancy + regional lymph nodes → risk of LN mets only 1% in HGD. BUT significant morbidity and mortality (2-5% at high volume centres) → CONSIDER with long segment/multifocal disease not amenable to endoscopic Mx
Type of Hiatus Hernia??
Hiatus hernia results from derangements in the normal anatomy - attenuation of the phreno-oesophageal ligament and laxity of the hiatus.
The phrenology-oesophageal ligament is the fused end-thoracic and endo-abdominal fascia that circumferentially inserts into the oesophageal musculature close to the squamous-columnar junction.
Type 1 - sliding (90%)L gastric cardia and LOS herniates into chest + phrenology-oesophageal ligament is attenuated but intact
Type 1 - true para-oesophageal hernia (3%).GOJ remains in usual position and gastric fungus herniates through the hiatus
Type 3 - mixed (7%). type one defect enlarges and fungus and upper stomach herniate into the chest. Predisposes to gastric volvulus.
Type 4 - large hiatus hernia with other organs in the hernia sac (1%) → 5% incidence of acute symptoms and volvulus
Giant Paraoesophageal hernia: ½ stomach + hernia >6cm on endoscopy + 5cm crural distance
Indications for Surgery in Hiatus Hernia
Type 1 - if symptomatic refractory to medical therapy or patient prefers surgery
All other types should be offered an operation if surgically fit due to high rate of complications if needing emergency repair (gastric volvulus, uncontrolled bleeding, strangulation, perforation or respiratory compromise). There is a 30% mortality after emergency surgery vs 1% for elective cases
30% of asymptomatic patients w/ para-oesophageal hernias will potentially develop devastating complications - such as strangulation or perforation
Types of Hiatus Hernia Repair Failure?
MORTALITY 1.4%, leak rate 2.5%
1A: fundoplication slips into chest
1B: Hiatus hernia recurs but wrap remains in abdomen
2: paraoesophagheal hiatus hernia
3: Wrap malpositioned
Patients with long standing HH have delayed gastric emptying after repair due to atrophic gastric musculature and vagal neuropraxia during dissection
Anatomical Classification of Gastric volvulus?
Organoaxial (60%) around longitudinal axis - strangulation in up to 30%. Predisposed by large paraoesophagheal hernia
Mesoentericoaxial - 30%: around the transverse axis
What does this XR show?
CXR demonstrating a retro cardiac air fluid level and another one below the diaphragm. Barium swallow with obstruction at the level of the volvulus would confirm the diagnosis of GASTRIC VOLVULUS
▪ organoaxial volvulus -> lies in a horizontal plane
- *▪** mesenteroaxial volvulus -> spherical stomach on supine images but- Due to anatomical abnormalities that result in abnormal mobility of the stomach two air-fluid levels on upright films, with the antrum positioned superior to the fundus
- *▪ Abnormal course of NGT**
Caustic Oesophageal Injury
- 30-50% will develop strictures after caustic injury
- Manage with endoscopic dilatation - delay 6 weeks post injury to minimise risk of perforation
- 0.5% risk of perforation at dilatation
- Consider surgery if young patients as likely to require multiple dilatation with cumulative risk of perforation + RISK of oesophageal Cancer is increased 1000x after caustic injury + 16% risk of SCC
*
What is a B ring?
A B ring is a mucosal structure (smooth and thin) at thsquamocolumnar junction. A Schatzki’s ring is a narrowed B ring.
6-14% of barium swallows for dysphagia
Schatzki’s ring found on 13% of endoscopies for dysphagia.
What is diffuse oesophageal spasm?
A motility disorder where normal peristalsis is replaced by simultaneous, repetitive high amplitude disordered contraction
Physiology unclear. F>M, 5 x less common than achalasia.
Worsened by emotional stress(associated with IBS/pyloric spasm) - psych input + cold liquids, acid reflux and biliary colic
Oesophagogram - corkscrew oesophagus (tertiary contractions and late disease), distal bird beak narrowing
Manometry: simultaneous high amplitude or long duration, multi peaked contractions (120mmHg, <2.5sec) occurs after >10% wet swallows
What is Nutcracker/ Jackhammer Oesophagus?
Hyper contractile oesophagus.
Affects oesophageal body; hypertensive peristalsis or high amplitude peristaltic contractions.
High-amplitude contractions (>180mmHg) with normal peristalsis during standard manometry → normal LOS, relaxation after every wet swallow, distal contractile integral >8000
Commonest motility disorder. M=F
oesophagogram may be normal
Mx: avoid triggers, muscle relaxants, endoscopic bogie dilatation
Systemic Sclerosis? CREST?
Autoimmune collagen vascular disease characterised by thickening, oedema and sclerosis of the skin associated with subcutaneous calcinosis
- C-Calcinosis
- R - Raynaud’s phenomenon
- E-oesophageal Dysmotility
- S - sclerodactyly
- T - Telangiectasia
Visceral involvement is rare apart from the oesophagus → affected in 80%: smooth muscle atrophy affecting LOS, weak peristalsis, reflux is common
Manometry - almost no peristalsis or loss of tone
Mx - PPI, manage strictures and complications
Integrated Relaxation Pressure (IRP) is the mean of the 4 seconds of maximum deglutive relaxation in the 10 second window beginning at the upper oesophageal sphincter relaxation referenced to gastric pressure
Distal contractile integral is the amplitude x duration x length of the distal oesophageal contraction exceeding 20mmHg from the transition zone to the proximal margin of the lower oesophageal sphincter.
Achalasia Oesophagogram (Barium swallow)
- Hold up in distal oesophagus, dilatation of oesophageal body, peristaltic dysfunction, tapering to ‘birds beak’ stricture of distal oesophagus
- dilated oesophagus with distal narrowing → birds beak
- sphincter spasm, dilated oesophageal body, delayed emptying
- Lack of gastric bubble (tight LOS not allowing air to pass)
- LATE PHASE → megaoesphagus, (>6cm) sigmoidal oesophagus, massive oesophageal dilatation
Zenker’s Diverticulum - Pharyngo-oesophageal
Due to loss of tissue elasticity
False diverticulum - doesn’t contain all layers of oesophageal wall (mucosa and submucosa)
Found at Killian’s triangle → between oblique fibres of the thyropharygeus and horizontal fibres of cricopharyngeus (2 parts of inferior constrictors). Mucosa/submucosa dissect down left side of oesophagus into the superior mediastinum and then posteriorly into the prevertebral space.
Treatment - open repair through the side of the neck. <2cm → myotomy of proximal and distal thyropharyngeus and cricopharyngeus. >2cm myotomy and the excision of sac. Diverticulopexy → fixing sac to posterior pharynx (not prevertebral fascia)
