Download MBBS Surgery Presentations 20 Esophagus Surgical Anatomy Lecture Notes

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