Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Surgery 20 Esophagus Surgical Anatomy PPT-Powerpoint Presentations and lecture notes
Esophagus- surgical anatomy
Anatomy
Relations...
? Right side- mediastinal pleura &
terminal part of azygous vein
? Left side- left subclavian artery,
aortic arch, thoracic duct,
mediastinal pleura
? When esophagus pierces the
diaphragm, it is accompanied by
two vagi, branches of left gastric
artery & lymphatic vessels.
? In abdomen ? left lobe of liver
anteriorly & left crus of diaphragm
posteriorly.
Constrictions
I ? Pharyngo-esophageal junction
-15cm from incisor teeth.
I - Aortic arch and left bronchus
crosses esophagus
anteriorly- 25cm from
incisor teeth.
Clinical importance of constrictions of
esophagus
? Common site for lodgment of foreign body
? Common site for stricture formation after corrosive ingestion
? Common site for carcinoma of esophagus
? Difficult sites for passage of esophagoscope.
Length of the Esophagus
? The distance between the cricoid cartilage and the gastric orifice.
? In adults, it ranges from 22 to 28 cm, 3 to 6 cm of which is located in
the abdomen.
? length of the esophagus is related to the subject's height rather than
sex.
? Cervical ? 5cm
? Thoracic -18-20cm
? Abdomen ? 2-4cm
Blood supply
? Upper 1/3 ? inferior thyroid
artery
? Middle 1/3 ? direct branches
from aorta.
? Lower 1/3 ? left gastric artery
Venous drainage
? Upper 1/3 ? inferior thyroid vein
? Middle 1/3 ? Azygous and hemi-
azygous vein.
? Lower 1/3- left gastric vein
Nerve supply (Extrinsic)
? Esophageal plexus ? formed by
vagus nerves by joining with
sympathetic nerves below the
root of lungs.
? LARP- left vagus anteriorly
? Right vagus posteriorly
Nerve suply
? Extrinsic ?vagus
? Intrinsic ?
? Auerbach /myentric plexus - between longitudinal and circular muscle
? Peristalsis
? Meissner's plexus-
at submucosal level ?
for secretion
? Meissner's submucosal plexus is sparse in the esophagus.
? The parasympathetic nerve supply is mediated by branches of the
vagus nerve
? that has synaptic connections to the myenteric (Auerbach's) plexus.
Lymphatic drainage
? Upper 1/3-
? deep cervical nodes.
? Middle 1/3-
? superior & posterior mediastinal
nodes
? Lower 1/3-
? celiac nodes
Diameter of the Esophagus
? The esophagus is the narrowest tube in the intestinal tract.
? At rest, the esophagus is collapsed; it forms a soft muscular tube .
? Flat in its upper and middle parts, with a diameter of 1.6 cm.
? The lower esophagus is rounded, and its diameter is 2.4 cm.
Musculature
? The musculature of the upper
esophagus & UES is striated.
? This is fol owed by a transitional
zone of both striated and smooth
muscle.
? proportion of the smooth muscle.
progressively increasing.
? In the lower half of the esophagus,
there is only smooth muscle.
? It is lined throughout with
squamous epithelium.
Layers
1. Mucosa ?
? epithelium
? Basement membrane
? Lamina Propria
2. Submucosa- strongest layer
3. Muscular propria-
? Inner circular
? Outer longitudinal
4. Adventitia ?visceral peritoneum
Periesophageal Tissue, Compartments, and
Fascial Planes
? Unlike the general structure of the digestive tract, the esophageal
tube has neither mesentery nor serosal coating.
? Its position within the mediastinum and a complete envelope of
loose connective tissue allow the esophagus extensive transverse
and longitudinal mobility.
? The esophagus may be subjected to easy blunt stripping from the
mediastinum.
Clinical relevance
? The connective tissues in which the esophagus and trachea are
embedded are bounded by fascial planes,
? the pretracheal fascia anteriorly and
? the prevertebral fascia posteriorly.
? In the upper part of the chest, both fascia unite to form the carotid
sheath.
Tunica Adventitia
? This thin coat of loose
connective tissue envelops the
esophagus.
? connects it to adjacent
structures,
? contains small vessels, lymphatic
channels, and nerves.
Tunica Muscularis
? The tunica muscularis coats the
lumen of the esophagus in two
layers :
? the external muscle layer paral els
the longitudinal axis of the tube,
? the muscle fibers of the inner layer
are arranged in the horizontal axis.
? For this reason, these muscle layers
are classical y cal ed longitudinal
and circular, respectively.
Tela Submucosa
? The submucosa is the connective tissue layer that lies between the
muscular coat and the mucosa.
? It contains a meshwork of small blood and lymph vessels, nerves, and
mucous glands.
? The duct of deep esophageal glands pierce the muscularis mucosae.
Tunica Mucosa
? The mucous layer is composed of three components:
? the muscularis mucosae,
? the tunica / lamina propria, and
? the inner lining of nonkeratinizing stratified squamous epithelium .
Physiology of the Esophagus and Its
Sphincters
Physiology
? The musculature of the esophagus = predominantly striated at the
level of the UES and proximal 1 to 2 cm of the esophagus.
? mixed striated = smooth muscle transition zone spanning 4 to 5 cm
? Entirely smooth muscle structure = in the distal 50% to 60% of the
esophagus, including the LES
SWALLOWING PROCESS
? Normal human subjects swallow on average 500 times a day.
? The act of swallowing can be divided into three stages:
1. the oral (voluntary) stage,
2. the pharyngeal (involuntary) stage, and
3. the esophageal stage.
? These stages are a continuous process closely coordinated through
the medullary swallowing centers.
Esophageal Stage
? The esophageal stage of swallowing starts once the food is
transferred from the oral cavity through the UES into the esophagus.
? This active process is achieved by contractions of the circular and
longitudinal muscles of the tubular esophagus and coordinated
relaxation of the LES.
? Esophageal peristalsis is controlled by afferent and efferent
connections of the medullary swallowing center via the vagus nerve
(cranial nerve X).
? The vagus nerve carries both stimulating (cholinergic) and inhibitory
(noncholinergic, nonadrenergic) information to the esophageal
musculature.
? In addition to the central nervous system control, the myenteric
(Auerbach) plexus
? plays a major role in coordinating peristalsis in the smooth muscle portion of
the distal esophagus.
Esophageal peristalsis
? Esophageal peristalsis is the result of sequential contraction of the
circular esophageal muscle.
? Three distinct patters of esophageal contractions have been
described:
1. Primary peristalsis
2. Secondary peristalsis
3. Tertiary contractions.
Primary peristalsis
? Primary peristaltic contractions are the usual form of the contraction
waves of circular muscles that progress down the esophagus;
? they are initiated by the central mechanisms that follow the
voluntary act of swallowing.
? During primary peristalsis, the LES is relaxed, starting at the initiation
of swallowing and lasting until the peristalsis reaches the LES.
Secondary peristalsis
? Secondary peristaltic contractions are the contraction waves of the
circular esophageal muscle occurring in response to esophageal
distention.
? They are not a result of central mechanisms.
? The role of secondary peristaltic contractions is to clear the
esophageal lumen of ingested material not cleared by primary
peristalsis or material that is refluxed from the stomach.
? Tertiary contractions are primarily identified during barium x-ray
studies and represent non-peristaltic contraction waves that leave
segmental indentations on the barium column.
LES
? Normal LES resting pressure ranges from 10 to 45 mm Hg above the
gastric baseline level.
? The function of the LES is to
? prevent gastroesophageal reflux and
? to relax with swallowing to allow movement of ingested food into the
stomach.
Perforation of the oesophagus
? Causes -
1. usually iatrogenic (at therapeutic endoscopy) or
2. due to `barotrauma' (spontaneous perforation).
3. Pathological perforation- rare
4. Penetrating injury
Barotrauma (spontaneous perforation, Boerhaave syndrome)
? This occurs classically when a person vomits against a closed glottis.
? The pressure in the oesophagus increases rapidly, and the
oesophagus bursts at its weakest point in the lower third, sending a
stream of material into the mediastinum and often the pleural cavity
as well.
? The condition was first reported by Boerhaave , who reported the
case of a grand admiral of the Dutch fleet who was a glutton and
practised auto emesis.
Boerhaave syndrome...
? Most serious type of perforation
? because of the large volume of material that is released under pressure.
? mediastinitis
? Barotrauma has also been described in relation to other pressure
events when the patient strains against a closed glottis (e.g.
defaecation, labour, weight-lifting).
Diagnosis of spontaneous perforation
? history
? severe pain in the chest or upper abdomen following a meal or a bout of drinking.
? shortness of breath
? O/E-
? rigidity on examination of the upper abdomen, even in the absence of any peritoneal
contamination.
? D/D
? myocardial infarction,
? perforated peptic ulcer or
? pancreatitis if the pain is confined to the upper abdomen.
Boerhaave syndrome...
1. Chest x-ray - confirmatory
? air in the mediastinum, pleura or peritoneum.
2. A contrast swallow or
3. CT scan
Pathological perforation
? Free perforation of ulcers or tumors of the oesophagus into the
pleural space is rare.
? Erosion into an adjacent structure with fistula formation is more
common.
? Aerodigestive fistula is most common and usually encountered in
primary malignant disease of the oesophagus or bronchus.
? Covering the communication with a self-expanding metal stent is the
usual solution.
Penetrating injury
? Perforation by knives and bullets is uncommon
Instrumental perforation
? Instrumentation is by far the most common cause of perforation.
? Incidence - 1:4000 examinations /UGIE
Diagnosis of instrumental perforation
? History and physical signs may be useful pointers to the site of
perforation.
1. Cervical perforation:
? pain localised to the neck,
? hoarseness,
? painful neck movements and
? subcutaneous emphysema.
2. Intrathoracic and intra-abdominal perforations,
(more common),
? Immediate symptoms and signs
? chest pain,
? haemodynamic instability,
? oxygen desaturation .
? evidence
of
subcutaneous
emphysema,
pneumothorax
or
hydropneumothorax.
Treatment of oesophageal perforations
? Perforation of the oesophagus usually leads to mediastinitis.
? The loose areolar tissues of the posterior mediastinum allow a rapid
spread of gastrointestinal contents.
? Aim of treatment
? limit mediastinal contamination and
? prevent or deal with infection.
Decision between operative and non-
operative management rests on four factors
1. the site of the perforation (cervical versus thoraco-abdominal
oesophagus);
2. the event causing the perforation (spontaneous versus
instrumental);
3. underlying pathology (benign or malignant);
4. the status of the oesophagus before the perforation (fasted and
empty versus obstructed with a stagnant residue).
Non-operative treatment of Instrumental
perforations
? Cervical oesophagus - are usually small perforation and can nearly
always be managed conservatively.
? The development of a local abscess is an indication for cervical
drainage preventing the extension of sepsis into the mediastinum.
Indication for non-operative management
(thoraco-abdominal perforation)
? when the perforation is detected early and prior to oral alimentation.
? absence of
? crepitus,
? diffuse mediastinal gas,
? Hydro-pneumothorax or pneumo-peritoneum;
? mediastinal containment of the perforation with no evidence of widespread
extravasation of contrast material;
? no evidence of ongoing luminal obstruction or a retained foreign body.
? patients who have remained clinically stable despite diagnostic delay.
Principles of non-interventional management
? nasogastric suction and
? broad-spectrum intravenous antibiotics
Indication of Surgical management
? unstable with sepsis or shock;
? have evidence of a heavily contaminated mediastinum, pleural space
or peritoneum;
? have widespread intra-pleural or intra-peritoneal extravasation of
contrast material.
Surgery
? direct repair,
? the deliberate creation of an external fistula or,
? rarely, oesophageal resection with a view to delayed reconstruction.
? Direct repair
? if the perforation is recognised early (within the first 4?6 hours) and the
extent of mediastinal and pleural contamination is small.
? After 12 hours, the tissues become swollen and friable , primary
repair not possible.
MALLORY?WEISS SYNDROME
? Forceful vomiting may produce a mucosal tear at the cardia rather
than a full perforation.
? In Boerhaave's syndrome, vomiting occurs against a closed glottis,
and pressure builds up in the oesophagus.
? In Mallory? Weiss syndrome, vigorous vomiting produces a vertical
split in the gastric mucosa, immediately below the squamo-columnar
junction at the cardia in 90 per cent of cases.
? In only 10 per cent is the tear in the oesophagus.
MALLORY?WEISS SYNDROME...
? Clinical feature
? Haematemesis
? Surgery is rarely required.
This post was last modified on 08 April 2022