Cervical Esophagus

The cervical esophagus is the uppermost portion of the esophagus. It begins at the pharyngoesophageal junction, where the inferior part of the pharynx continues into the esophagus, and descends through the lower neck before entering the thorax through the superior thoracic aperture.

The esophagus begins approximately at the level of the lower border of the cricoid cartilage and the C6 vertebra. In the neck, it lies immediately posterior to the trachea and anterior to the cervical vertebral column and prevertebral muscles. The cervical esophagus is therefore positioned within the visceral compartment of the neck and is closely related to the thyroid gland, recurrent laryngeal nerves, carotid sheaths, and surrounding cervical fascial planes.

The cervical segment is clinically important because it contains the transition from the pharynx to the esophagus, includes the region of the upper esophageal sphincter, and is related to structures that may be encountered during neck surgery, endoscopy, and procedures involving the thyroid, trachea, or cervical spine.

Extent

The cervical esophagus extends from the pharyngoesophageal junction to the superior thoracic aperture.

It begins at approximately the level of C6 and continues inferiorly until it enters the superior mediastinum.

Pharyngoesophageal Junction

The pharyngoesophageal junction marks the transition from the laryngopharynx to the esophagus.

It lies near the lower border of the cricoid cartilage at approximately the C6 vertebral level.

Relationship to the Cricoid Cartilage

The beginning of the esophagus is conventionally identified at the level of the inferior border of the cricoid cartilage.

The cricoid cartilage therefore provides an important surface and surgical landmark for the upper end of the esophagus.

Vertebral Level

The cervical esophagus begins at approximately the C6 vertebral level.

It descends through the lower neck toward the superior thoracic aperture, where it continues as the thoracic esophagus.

Course

From its origin, the cervical esophagus descends posterior to the trachea.

Although initially near the midline, the esophagus may deviate slightly toward the left as it approaches the thoracic inlet.

Transition to the Thoracic Esophagus

The cervical portion becomes continuous with the thoracic esophagus as the organ passes through the superior thoracic aperture into the superior mediastinum.

There is no abrupt structural boundary between the cervical and thoracic portions.

General Position in the Neck

The cervical esophagus lies within the visceral compartment of the neck.

Its most important immediate relationship is with the trachea anteriorly.

Anterior Relations

The principal anterior relation of the cervical esophagus is the trachea.

Other anterior or anterolateral relationships may include structures associated with the thyroid gland and connective tissues of the visceral compartment.

Relationship to the Trachea

The trachea lies directly anterior to the cervical esophagus.

Loose connective tissue between the two structures allows movement during swallowing and provides a plane that can be identified surgically.

Tracheoesophageal Grooves

The longitudinal spaces between the lateral margins of the trachea and esophagus are known as the tracheoesophageal grooves.

These grooves are important because the recurrent laryngeal nerves commonly ascend within or close to them.

Posterior Relations

Posterior to the cervical esophagus are the prevertebral fascia, prevertebral muscles, and cervical vertebral column.

These relationships separate the esophagus from the bony cervical spine.

Relationship to the Vertebral Column

The cervical vertebral column lies posterior to the esophagus, with prevertebral muscles and fascial layers intervening.

This relationship is important during anterior approaches to the cervical spine.

Prevertebral Muscles

The longus colli and related prevertebral musculature lie posterior to the cervical esophagus.

The prevertebral fascia covers these muscles and contributes to the fascial organization of the posterior neck spaces.

Lateral Relations

The cervical esophagus has important lateral relationships with the thyroid gland, carotid sheaths, and recurrent laryngeal nerves.

The exact relationships vary with the level within the neck.

Relationship to the Thyroid Gland

The thyroid lobes lie anterolateral to the upper cervical esophagus and trachea.

The close relationship between the thyroid, esophagus, and recurrent laryngeal nerves is particularly important during thyroid surgery.

Relationship to the Carotid Sheaths

The carotid sheaths lie laterally to the cervical visceral compartment.

Each sheath contains the common carotid artery, internal jugular vein, vagus nerve, and associated lymphatic and sympathetic structures.

Recurrent Laryngeal Nerves

The recurrent laryngeal nerves ascend in close relationship to the cervical esophagus, commonly within or near the tracheoesophageal grooves.

They provide motor innervation to most intrinsic muscles of the larynx and also contribute branches to the esophagus.

Right Recurrent Laryngeal Nerve

The right recurrent laryngeal nerve loops around the right subclavian artery before ascending toward the larynx.

Its course in the neck can be somewhat more oblique and variable than that of the left recurrent laryngeal nerve.

Left Recurrent Laryngeal Nerve

The left recurrent laryngeal nerve loops around the aortic arch in the thorax and then ascends toward the neck.

It commonly follows a relatively consistent course within the left tracheoesophageal groove.

Relations of the Cervical Esophagus

Direction	Important Relations
Anterior	Trachea
Posterior	Prevertebral fascia, prevertebral muscles and cervical vertebral column
Lateral	Thyroid lobes and carotid sheaths
Anterolateral	Recurrent laryngeal nerves in or near tracheoesophageal grooves

Wall of the Cervical Esophagus

The wall of the cervical esophagus follows the general organization of the gastrointestinal tract but has several distinctive features.

From the lumen outward, the major layers are the mucosa, submucosa, muscularis externa, and an outer connective tissue adventitia.

Mucosa

The esophageal mucosa is lined by nonkeratinized stratified squamous epithelium.

This epithelium provides protection against mechanical abrasion as swallowed material passes toward the stomach.

Lamina Propria

Beneath the epithelium lies the connective tissue of the lamina propria.

It contains small blood vessels, immune cells, and other connective tissue components.

Muscularis Mucosae

The muscularis mucosae forms the deepest portion of the mucosa and consists primarily of longitudinally oriented smooth muscle fibers.

Submucosa

The submucosa consists of connective tissue containing blood vessels, lymphatics, nerves, and esophageal glands.

Its elastic properties allow the esophageal lumen to expand during passage of a swallowed bolus.

Esophageal Glands

Submucosal esophageal glands produce mucus that helps lubricate the luminal surface.

This secretion assists the passage of swallowed material through the esophagus.

Muscularis Externa

The muscularis externa generally contains an inner circular and outer longitudinal muscle layer.

These layers generate coordinated contractions that propel material through the esophagus.

Skeletal Muscle in the Cervical Esophagus

The upper portion of the esophagus is composed predominantly of skeletal muscle.

This reflects its functional continuity with the pharyngeal musculature and the transition from voluntary initiation of swallowing to involuntary esophageal transport.

Muscle Transition Along the Esophagus

Region	Predominant Muscle Type
Upper third	Skeletal muscle
Middle third	Mixture of skeletal and smooth muscle
Lower third	Smooth muscle

Adventitia

Most of the cervical esophagus is surrounded externally by adventitia rather than a serosal covering.

The adventitia consists of connective tissue that blends with surrounding cervical tissues and helps anchor the esophagus while permitting movement.

Absence of Serosa

The cervical esophagus does not possess the complete serosal covering typical of many intraperitoneal gastrointestinal organs.

This anatomical feature affects the way inflammation and disease can extend into surrounding tissues.

Upper Esophageal Sphincter

The upper esophageal sphincter is a functional high-pressure region at the junction between the pharynx and esophagus.

The cricopharyngeal part of the inferior pharyngeal constrictor is a major muscular component of this sphincteric region.

Cricopharyngeus

The cricopharyngeus forms the inferior portion of the inferior pharyngeal constrictor.

Its fibers arise from the cricoid cartilage and encircle the pharyngoesophageal junction.

Function of the Upper Esophageal Sphincter

At rest, the upper esophageal sphincter remains tonically contracted.

During swallowing it relaxes transiently, allowing the bolus to pass from the pharynx into the cervical esophagus.

Functions of the Upper Esophageal Sphincter

• Controls passage from pharynx to esophagus
• Helps prevent entry of air into the esophagus during respiration
• Helps limit retrograde movement of esophageal contents into the pharynx
• Coordinates with pharyngeal muscles during swallowing

Pharyngoesophageal Constriction

The beginning of the esophagus is one of the normal anatomical constrictions encountered along the esophageal lumen.

This pharyngoesophageal constriction occurs near the level of the cricoid cartilage.

Importance of Esophageal Constrictions

Normal constrictions are clinically important because swallowed foreign bodies may become lodged at these sites.

They also represent regions where resistance may be encountered during endoscopic instrumentation.

Swallowing

The cervical esophagus participates in the transition between the pharyngeal and esophageal phases of swallowing.

Once the bolus passes through the upper esophageal sphincter, coordinated muscular contractions propel it inferiorly.

Pharyngeal Phase

During the pharyngeal phase of swallowing, coordinated contraction of pharyngeal muscles directs the bolus toward the pharyngoesophageal junction.

The upper esophageal sphincter relaxes to permit entry into the esophagus.

Esophageal Phase

During the esophageal phase, peristaltic contractions move the bolus through the cervical esophagus and into the thoracic portion.

This process continues until the swallowed material reaches the stomach.

Primary Peristalsis

Primary peristalsis is the continuation of the coordinated swallowing wave into the esophagus.

Sequential muscular contraction moves the bolus distally.

Arterial Supply

The cervical esophagus receives arterial blood primarily from branches of the inferior thyroid arteries.

These vessels form longitudinal and circumferential anastomoses within and around the esophageal wall.

Inferior Thyroid Artery

The inferior thyroid artery usually arises from the thyrocervical trunk of the subclavian artery.

In addition to supplying the thyroid gland and surrounding structures, it gives branches to the cervical esophagus.

Esophageal Arterial Anastomoses

Arteries supplying the esophagus form extensive anastomotic connections along its length.

Cervical branches communicate inferiorly with esophageal branches supplying the thoracic segment.

Venous Drainage

Venous blood from the cervical esophagus drains through an esophageal venous plexus and primarily reaches the inferior thyroid veins.

These veins ultimately communicate with the brachiocephalic venous system.

Inferior Thyroid Veins

The inferior thyroid veins descend from the thyroid and neighboring cervical visceral structures.

They commonly drain into the brachiocephalic veins and receive tributaries from the cervical esophagus.

Lymphatic Drainage

Lymphatic vessels from the cervical esophagus drain primarily toward deep cervical and paratracheal lymph nodes.

Longitudinal lymphatic channels within the esophageal wall permit communication between lymphatic territories at different levels.

Deep Cervical Lymph Nodes

The deep cervical lymph nodes form a major lymphatic chain along the internal jugular vein.

They receive lymph directly or indirectly from numerous structures of the head and neck, including the cervical esophageal region.

Paratracheal Lymph Nodes

Paratracheal lymph nodes lie adjacent to the trachea and receive lymph from structures within the cervical visceral compartment.

They contribute to lymphatic drainage from the cervical esophagus.

Innervation

The cervical esophagus receives autonomic and motor innervation through branches associated principally with the vagus nerves, recurrent laryngeal nerves, and sympathetic trunks.

Vagal Innervation

The vagus nerves provide parasympathetic fibers to the esophagus.

In the cervical region, esophageal branches are closely associated with the recurrent laryngeal nerves and vagal pathways.

Recurrent Laryngeal Nerve Contributions

The recurrent laryngeal nerves give branches to the upper esophagus as they ascend through the tracheoesophageal region.

These branches participate in the motor and autonomic innervation of the proximal esophageal musculature.

Sympathetic Innervation

Sympathetic fibers reach the cervical esophagus from the cervical sympathetic trunks.

They contribute to the autonomic plexus surrounding the esophagus and its blood vessels.

Esophageal Plexus

Nerve fibers form plexuses on and within the esophageal wall.

These neural networks coordinate motor activity, glandular secretion, vascular tone, and sensory signaling.

Myenteric Plexus

The myenteric plexus lies between the circular and longitudinal layers of the muscularis externa.

It contributes importantly to coordination of esophageal motility.

Submucosal Plexus

The submucosal plexus lies within the submucosal region and participates in regulation of glandular secretion, local blood flow, and mucosal function.

Neurovascular Supply Summary

Feature	Main Structure
Arterial supply	Inferior thyroid arteries
Venous drainage	Inferior thyroid veins and esophageal venous plexus
Lymphatic drainage	Deep cervical and paratracheal nodes
Parasympathetic supply	Vagus and recurrent laryngeal branches
Sympathetic supply	Cervical sympathetic trunks

Cervical Fascial Relationships

The cervical esophagus is surrounded by connective tissue and fascial planes that permit movement during swallowing while maintaining its relationship with the trachea and other cervical viscera.

These fascial planes are clinically important because they can influence the spread of infection, air, blood, or leaked esophageal contents.

Retropharyngeal Region

The pharynx and upper esophagus lie anterior to deep cervical fascial spaces.

Infections originating in the pharyngeal or esophageal region may extend along these tissue planes toward the thorax.

Esophageal Perforation

Cervical esophageal perforation creates an abnormal communication between the esophageal lumen and surrounding cervical tissues.

Escaped air, saliva, food material, and microorganisms can spread through the fascial planes of the neck.

Spread Toward the Mediastinum

Because cervical fascial spaces communicate with the superior mediastinum, infection or contamination following esophageal injury can descend into the thorax.

This anatomical continuity makes prompt recognition of significant perforation important.

Foreign Bodies

The pharyngoesophageal junction is a common region where swallowed foreign bodies may become impacted because it represents a physiological narrowing of the upper digestive tract.

Endoscopy

During upper gastrointestinal endoscopy, the instrument passes through the pharynx, upper esophageal sphincter, and cervical esophagus before entering the thoracic esophagus.

Knowledge of the normal constriction at the pharyngoesophageal junction is important during instrumentation.

Zenker Diverticulum

Zenker diverticulum is a pharyngoesophageal pulsion diverticulum arising in the posterior region of the pharyngoesophageal junction.

It develops through an area of relative muscular weakness superior to the cricopharyngeus.

Killian Dehiscence

Killian dehiscence is a triangular area of relative weakness between portions of the inferior pharyngeal constrictor musculature.

It is the characteristic region through which a Zenker diverticulum develops.

Cricopharyngeal Dysfunction

Abnormal relaxation, coordination, or compliance of the cricopharyngeal region can interfere with passage of swallowed material into the esophagus.

This may contribute to oropharyngeal swallowing difficulty.

Dysphagia

Dysphagia refers to difficulty swallowing and can arise from structural or functional abnormalities involving the pharynx, upper esophageal sphincter, cervical esophagus, or more distal portions of the gastrointestinal tract.

The anatomical level at which symptoms are perceived does not always correspond exactly to the site of the underlying abnormality.

Cervical Esophageal Stricture

Narrowing of the cervical esophagus can result from inflammatory, neoplastic, traumatic, postoperative, or other structural processes.

Significant narrowing can interfere with normal passage of swallowed material.

Esophageal Carcinoma

Malignant tumors can arise within the cervical esophagus and may extend through the esophageal wall into neighboring structures.

The absence of a complete serosal covering and the presence of longitudinal lymphatic channels influence patterns of local and lymphatic spread.

Local Spread of Cervical Esophageal Tumors

Advanced lesions may involve neighboring structures such as the trachea, thyroid gland, recurrent laryngeal nerves, prevertebral tissues, or major cervical neurovascular structures.

Recurrent Laryngeal Nerve Involvement

Disease involving the cervical esophagus or neighboring tissues can affect a recurrent laryngeal nerve.

Because these nerves control most intrinsic laryngeal muscles, injury may alter vocal fold movement.

Thyroid Surgery

The close relationship between the cervical esophagus, thyroid gland, and recurrent laryngeal nerves is important during thyroidectomy and other operations in the central neck.

Recognition of the tracheoesophageal groove helps orient the surgeon to these structures.

Anterior Cervical Spine Surgery

Anterior approaches to the cervical vertebral column require mobilization of the cervical visceral structures, including the esophagus and trachea.

The esophagus is therefore potentially vulnerable to traction or direct injury during these procedures.

Cervical Esophagus on CT

On axial CT, the cervical esophagus is usually identified posterior to the trachea and anterior to the prevertebral musculature and cervical spine.

Its lumen may be collapsed or may contain small amounts of air or fluid.

Cervical Esophagus on MRI

MRI can demonstrate the soft tissue relationships of the cervical esophagus with the trachea, thyroid gland, vertebral column, muscles, and surrounding fascial planes.

Contrast Swallow Studies

Contrast swallow examinations can demonstrate the pharyngoesophageal junction and cervical esophageal lumen during swallowing.

They are useful for evaluating structural abnormalities, diverticula, narrowing, and aspects of swallowing function.

Endoscopic Evaluation

Direct endoscopic examination allows visualization of the mucosal surface of the cervical esophagus.

It can also permit biopsy or selected therapeutic procedures when clinically indicated.

Cervical Versus Thoracic Esophagus

Feature	Cervical Esophagus	Thoracic Esophagus
Location	Neck	Mediastinum
Superior limit	Pharyngoesophageal junction near C6	Superior thoracic aperture
Major anterior relation	Trachea	Trachea superiorly, then other mediastinal structures
Primary arterial source	Inferior thyroid artery branches	Esophageal branches from thoracic vessels
Major lymphatic drainage	Deep cervical and paratracheal nodes	Mediastinal lymphatic pathways

Key Anatomical Relationships

Structure	Relationship
Cricoid cartilage	Marks approximate level of esophageal origin
Trachea	Anterior
Recurrent laryngeal nerves	Ascend in or near tracheoesophageal grooves
Thyroid gland	Anterolateral
Carotid sheaths	Lateral
Prevertebral muscles	Posterior
Cervical vertebral column	Posterior

Key Features of the Cervical Esophagus

Feature	Key Point
Beginning	Lower border of cricoid cartilage at approximately C6
Superior continuity	Laryngopharynx
Inferior continuity	Thoracic esophagus
Major anterior relation	Trachea
Major posterior relations	Prevertebral fascia, muscles and cervical spine
Upper muscle type	Predominantly skeletal muscle
Outer covering	Adventitia
Upper sphincter	Functional region strongly associated with cricopharyngeus
Arterial supply	Primarily inferior thyroid artery branches
Venous drainage	Primarily inferior thyroid veins
Lymphatic drainage	Deep cervical and paratracheal nodes
Important nerves	Vagal and recurrent laryngeal branches with sympathetic contributions

Anatomical and Clinical Importance

The cervical esophagus forms the first segment of the esophageal pathway between the pharynx and stomach. Beginning near the lower border of the cricoid cartilage at approximately C6, it descends posterior to the trachea and continues through the superior thoracic aperture into the thoracic esophagus.

Its close relationships with the trachea, recurrent laryngeal nerves, thyroid gland, carotid sheaths, prevertebral muscles, and cervical spine make the cervical esophagus an important structure during operations involving the neck. The pharyngoesophageal junction also contains the functional upper esophageal sphincter, in which the cricopharyngeus plays a major role.

Knowledge of cervical esophageal anatomy is particularly important in understanding swallowing, Zenker diverticulum, foreign-body impaction, esophageal perforation, cervical esophageal tumors, and complications of thyroid or anterior cervical spine surgery.