COMPARTMENTS OF THE HEAD AND NECK – SURGICAL ANATOMY & APPLIED ASPECTS
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Fascial Spaces “The facial spaces or compartments are regions of loose C.T. that fill the areas between facial layers”. The concept of fascial ‘spaces’ is based on anatomists knowledge that all ‘spaces’, exist only potentially, until fasciae are separated by pus, blood, drains or a surgeon’s finger. www.indiandentalacademy.com
How did the concept of facial spaces arise? “If I have seen further, it is by standing on the shoulder of Gaints”. Issac Newton” • In the 1930s the classic anatomical studies of Grodinsky and Holyoke established the modern understanding of the fascial layers and the potential anatomical spaces through which infection can spread in head and neck. www.indiandentalacademy.com
What is fascia and its functions? • It is a sheet or layer of more / less condensed connective tissue. • Fascial layers are like tissue paper surrounding each item of clothing within a garment box, which allows them to pass over each other without their becoming unfolded. www.indiandentalacademy.com
Functions of the fascia • Acts as a musculovenous pump• Limits outward expansion of muscles as they contract. • Contraction of muscles compress the intramuscular veins (push the blood towards the heart). • Prevent penetrating objects eg knife & low velocity bullets from vital structures • They also afford the slipperiness that allows the structures in the neck to move & pass over one another esply during swallowing & turning the neck. • Determine the direction of spread of infection www.indiandentalacademy.com
CLASSIFICATION FASCIAE IN THE NECK
SUPERFICIAL (SCF)
DEEP (DCF)
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Superficial fascia Superficial fascia is not a fascial sheet in the classic sense, but rather a fatty loose connective tissue in which are embedded the www.indiandentalacademy.com voluntary muscles of facial expression and the platysma muscle.
Superficial fascia Skin + Superficial fascia + Platysma muscle
Complex morphological unit
Superficial musculoaponeurotic system (SMAS)
Clinical considerations: 1. Surgeons consider SMAS most important component of rhytidectomy / face-lift surgery / plastic surgery of the face. 2. Necrotizing fascitis – Infection of this fascia causes necrosis of the tissues in the subcutaneous space leading to necrotizing www.indiandentalacademy.com fascitis.
Deep fascia Superficial layer of deep fascia
Middle layer of deep fascia
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Deep layer of deep fascia
Superficial layer of deep cervical fascia
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Superficial layer of deep cervical fascia
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Middle layer of deep cervical fascia
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Buccopharyngeal fascia
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Deep layer of deep cervical fascia
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Deep layer of deep cervical fascia
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Schematic diagram showing the arrangement of deep neck spaces
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Schematic diagram showing the arrangement of deep neck spaces
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The greatest clinical implication of cervical fascia is that it divides the neck into potential spaces that function as a unit but are anatomically separate. Hyoid bone is considered the most important structure limiting the spread of infection. For this reason infection are classified by dividing the potential spaces into 3 general divisions: 1. Space of entire neck. 2. Supra hyoid spaces. 3. Infra hyoid spaces. www.indiandentalacademy.com
Classification of the spaces of Face & Neck I Spaces of the Face A.
Maxillary spaces 1. Buccal space. 2. Canine space. B. Mental space.
II Spaces of neck A.
Spaces involving the entire length of the neck. 1. Superficial space 2. Deep neck spaces (all involve only the posterior side of the neck) a) b) c) d)
Retropharyngeal space (Space 3). Danger space (Space 4) Prevertebral space (Space 5) Visceral vascular space (within carotid sheath). www.indiandentalacademy.com
B. Suprahyoid spaces: 1) Mandibular space • • • •
Submandibular space. Submental space. Sublingual space. Space of the body of the mandible.
2) Masticatory space. 3) Lateral pharyngeal space (Pharyngomaxillary, peripharyngeal / parapharyngeal). 4) Peritonsillar space. 5) Parotid space.
C. Infrahyoid space (involves anterior side of the neck only). 1. Pretracheal space. www.indiandentalacademy.com
Concepts about space infections • The spaces are not empty they contain various organs, nerves, blood vessels, salivary glands, lymph nodes and fat surrounded by loose fibrous connective tissue. • The spaces of head and neck are not perfectly enclosed they are pathways around the muscles through which infection can spread.
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Concepts about space infections • Infections within each space has its own diagnostic signs and tends to spread in an orderly, anatomic fashion from one space to another by continuous extension. • If the surgeon understands this process, he can anticipate the spread of infection into dangerous spaces and abort the process by timely incision and drainage. www.indiandentalacademy.com
Pathways of spread of dental infection
Pericoronitis of third molar area
Spread of infection from erupted and infected third molar area
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General pathways of spread of maxillary and mandibular infection
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Predisposing factors •
Primary predisposing factors leading to deep infection of the neck were: 1. Local dental disease like dental caries or diseases of the gums. 2. Lowered body resistance due to result of conditions such as tuberculosis, diabetes mellitus, syphiles, scurvy. Primary signs & symptoms of these infections: - Cellulitis / phlegmons. - Localized pain. - Tenderness. - Redness. www.indiandentalacademy.com - Edema of the overlying tissue.
Relationship of point of bone perforation to spread of infection
Infection enters soft tissue through thinnest bone
www.indiandentalacademy.com In respect
to buccinator muscle
Relationship of point of bone perforation to muscle attachment
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Stages of infections • • • •
Stage I – Inoculation Stage II – Cellulitis Stage III – Abscess Stage IV – Resolution
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Surgical anatomy of deep facial spaces of head and neck
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Buccal space
Clinical evaluation: Examination of the patient with the buccal space infection demonstrate swelling confined to the cheek with abscess forming beneath the buccal mucosa and bulging into the mouth. www.indiandentalacademy.com
• Haemophilus influenzae cellulitis with the marked buccal www.indiandentalacademy.com swelling.
Canine space / Infraorbital space
• Clinical evaluation: Patient exhibits swelling lateral to the nose obliterating the nasolabial fold, grouping at the corner of the mouth and swelling of the upper lip, edema occurs in the www.indiandentalacademy.com upper and lower lid that may close the eye.
Differential diagnosis of upper face infections
Dacrocystitis with minimal involvement of nasolabial fold.
Odontogenic cellulitis. The nasolabial fold is effaced. www.indiandentalacademy.com
Suprahyoid spaces 1) Mandibular space • • • •
Submandibular space. Submental space. Sublingual space. Space of the body of the mandible.
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Mandibular spaces Submandibular space
Clinical Evaluation: Infection mostly arises from 2nd or third molar. Induration and erythema in the submandibular area obliterating the mandibular line and extending to the level of hyoid bone. www.indiandentalacademy.com No trismus.
Submandibular space
Relationship of Sublingual.S with submandibular.S www.indiandentalacademy.com
Submandibular space abscess A.Contrast enhanced axial CT section demonstrating decreased myositis and fasciitis of RT submandibular space B. Contrast enhanced axial CT demonstrating deep and superficial portion of right submandibular space.
A
B
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Sublingual space
Clinical evaluation: Edema and induration of the floor of the mouth on the affected side displacing tongue medially and superiorly. Hot potato voice. Elevation of tongue to palate causing airway compromise. Prevents patient from extending tongue beyond the vermilion border of upper lip. www.indiandentalacademy.com
Submental space
Boundary Clinical evaluation Management Complications
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Ludwig’s Angina
Ludwig’s angina is a firm, acute, toxic cellulitis of the submandibular and sublingual spaces bilaterally and of the submental space. Three ‘fs’ of Ludwig’s Angina -feared -rarely fluctuant www.indiandentalacademy.com -often fatal
Ludwig’s Angina •
The original description of the disease was given by Wilhelm Friedrich von Ludwig.
•
Ludwig’s original description he emphasized that the angina
1.
Is characterized by rapidly spreading gangrenous cellulitis.
2.
Originates in the region of submandibular gland but never involves one single space and
3.
Arises from extension by continuity and not by lymphatics and
4.
Produces gangrene with serosanguinous, putrid infiltration but very little or no frank pus. www.indiandentalacademy.com
Ludwig’s Angina
Clinical evaluation: - It is characteristically aggressive and rapidly spreading. - Patient will appear toxic with elevation of WBC count, fever, chills. - Airway compromise occurring quickly and with little fore warning. - Drooling, dysphagia, mouth pain and neck stiffness are not uncommon. - Physical examination. - Anteriorly protruding tongue, induration and erythema of the floor of the mouth and indentation of the tongue by the teeth. - A woody induration in the suprahyoid region of neck. - Trismus is usually absent. www.indiandentalacademy.com
Management of Ludwig’s Angina • • • •
Hospitalization. Airway control – tracheostomy. Early I.v. antibiotics. External surgical exploration with division of mylohyoid muscle and drainage. • Blind or nasotracheal intubation is unsafe. • Drainage: ‘Classic’ horizontal incision midway between chin and hyoid bone is no longer advocated. • Bilateral through and through drainage of submandibular space with simultaneous exploration of submental and sublingual space is recommended. www.indiandentalacademy.com
Incision for surgical drainage of Ludwig’s Angina
X
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Masticator space
The masticatory spaces are called secondary spaces and are combination of four smaller spaces. Clinically if one space is involved with infection, this usually implies that all spaces are involved. These are known as secondary spaces because they are usually involved with infection via spread from one of the primary spaces like buccal, sublingual or www.indiandentalacademy.com submandibular.
Clinical examination • Difficulty in swallowing. • Severe pain. • Swelling extending over the ramus of the mandible with obliteration of subungular depression. • Marked trismus. • Posterior portion of tongue is impossible to depress. • No fluctuance • Parotid secretions are clear. • Patient is not acutely illed. www.indiandentalacademy.com
MASTICATOR SPACE- APPLIED ASPECTS. • Lesions which could present in this spaceNerve sheath tumours Mandibular & soft tissue sarcomas Dental tumours Cysts & abscesses Osteomyelitis
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Drainage of parotid and Masseter space infection
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Lateral pharyngeal space infection
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Drainage of lateral pharyngeal space
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Lateral pharyngeal space infections • It lies immediately posterior and lateral to the pharynx and extend forward into the sublingual region so that together they form a ring about the pharynx. • Anatomically the lateral pharyngeal space may be thought of as an inverted pyramid-the base of the pyramid being the skull base and the apex the hyoid bone. • In 1929 Mosher called this potential avenue of infection the “Lincoln highway” of the body. www.indiandentalacademy.com
Lateral pharyngeal space infections
This space is further divided by the styloid process and the surrounding musculature into a prestyloid and post styloid compartment. The prestyloid compartment contains fat, lymph nodes and internal maxillary artery. The post styloid compartment contains the carotid artery, internal jugular vein, cervical sympathetic chain and cranial nerves IX, X, XI, XII
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Clinical evaluation • Firm induration with surrounding erythema lateral and anterior to sternocleidomastoid muscle between angle of mandible and hyoid bone. • Difficulty of flexing and turning of neck. • Trismus secondary pterygoid muscle involvement. • Dysphagia. • Dyspnea. • Extended into mediastenum along the carotid sheath (surgical emergency and prompt intervention with thoracic surgery indicated). • Diagnostic evaluation www.indiandentalacademy.com • Chest CT scan, Gram stain, Chest radiographs
Management • • • •
Hospitalization with I.v. antibiotics. Airway protection. Rapid surgical drainage. Surgical approach always through neck not through oral cavity. • Incision is made at the level of hyoid bone across the sternocleidomastoid muscle. • If abscess not present that means the infection material had no time to form an abscess. www.indiandentalacademy.com
Complications • Suppurative jugular venous thrombosis. • Patient will have shaking chills, spiking fevers, prostration. • Tenderness at the mandibular angle and along sternocleidomastoid muscle. • Carotid artery rupture. • Internal carotid artery most commonly involved than external. www.indiandentalacademy.com
Peritonsillar space infection • Peritonsillar space consists of an area of loose CT between the fibrous capsule of the palatine tonsil medially and superior constrictor laterally. Clinical evaluation: • 3-7 day H/o pharyngitis that has been Rx with antibiotics without resolution. • Severe sore throat, dysphagia, Odyonophagia and referred otalgia. • The speech is muffled and classically described as hot potato voice. • Trismus is not present www.indiandentalacademy.com • Management
Parotid space infection • The parotid space infection is the name applied to the closed space occupied by the parotid gland fascial nerve, lymph nodes ECA and the posterior fascial vein. Its walls are formed by split of superficial layer of deep cervical fascia. • Clinical evaluation: Symptoms of the infection in the parotid space include marked swelling of the angle of the jaw without associated trismus or pharyngeal swelling. • The symptoms of parotitis include pain and induration over the involved gland. Purulent secretions may sometimes be expressed after massage from the parotid depth. • The symptoms of patients with parotid gland abscess will manifest in much the same way as those of patients with parotitis but very characteristics pitting edema of the gland is the pathognamicwww.indiandentalacademy.com for parotid gland abscess. •
Relationship showing lateral pharyngeal, peritonsillar and pterygomandibular spaces
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Deep neck infections • All involve only posterior side of neck. a)Retropharyngeal space (space 3, posterior visceral space). b)Danger space (space 4). c)Prevertebral space (space 5). d)Visceral vascular space (within the carotid sheath) www.indiandentalacademy.com
Principles for Rx of the deep neck spaces • 1. 2. 3.
4. 5.
Benjamin J. Gans, in his Atlas of oral
surgery, articulated these principles: Drain all significant deep space infections. Do not wait for fluctuance. Fluctuance is a late sign. Determine incision placement, incisions designed to avoid important anatomical structures, provide dependent drainage and leave cosmetically acceptable scar. Institute definitive treatment as soon as possible, Offending tooth to be removed. www.indiandentalacademy.com Check for systemic disease.
Retropharyngeal space Retropharyngeal space is the potential space sandwiched between alar and prevertebral layers of deep layer of the deep investing fascia. Extension
Base of the skull Mediastinum
Most dangerous of all types of deep neck infections
Two compartments: Suprahyoid
Sagittal section of retropharyngeal space
Infrahyoid
1. Only fat 1. Lymph nodes and fat.www.indiandentalacademy.com
Clinical Evaluation • Children less than 4 yrs commonly affected. • In adults it manifests as cold abscess. • Sore throat, dysphagia, odynophagia, difficulty handling secretions. • Hot potato voice. Early signs:
Late signs
•Refusal to take food.
•Neck tilts towards involved side.
•Cervical lymphadenopathy.
•Hyperextended complete inability to flex the neck.
•Slight neck rigidity. •Noisy breathing due to laryngeal edema.
•Respiratory embarssment may occur if abscess not ruptured or drained.
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Oblique section of retropharyngeal space www.indiandentalacademy.com
Mediastinits, occurring 9 days after drainage of the retropharyngeal space
CT Scan A-P view
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Diagnosis of the soft tissue radiograph for retropharyngeal space infection Step I: • Look at the prevertebral or retropharyngeal soft tissue shadow. • In the area of 2nd and 3rd CV, RP soft tissue shadow should be less than 7mm wide. • In the area of 6 cervical vertebra soft tissue shadow is behind the trachea and includes the thickness of esophagus making it approx. Children – 14mm wide adults – 22mm wide www.indiandentalacademy.com
Step II. The second feature that should be looked for in this radiograph is the presence of gas. Anaerobic bacteria will produce gas that can be seen as emphysema in the soft tissues of the neck
Areas of Emphysema in the submandibular and lateral www.indiandentalacademy.com pharyngeal space region
Step III. - Finally, the lateral soft tissue radiograph will show the curve of the cervical spine - Loss of the lordotic curve is a strong indication of retropharyngeal space infection. - Tipping of the head forward in sniffing position to maintain an open airway.
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Management of Retropharyngeal space infection
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Danger space
• Danger space or space for cannot be reliably differentiated from the retropharyngeal space on imaging and is therefore combined with retropharyngeal space for discussion. www.indiandentalacademy.com
Prevertebral space • Is found by the deep cervical fascia. • Facia attaches to the transverse process of the cervical vertebra dividing this space into anterior and posterior compartments. Anterior compartment contains: -Vertebral bodies. -Spinal cord. -Vertebral arteries. -Phrenic nerve. -Prevertebral and scalene muscles Posterior compartment contains: -Posterior vertebral elements. -Paraspinous muscles. www.indiandentalacademy.com
Lesions in prevertebral space • Arise in the vertebral body, intervertebral disc spaces Or Prevertebral / paraspinous muscles. E.g. vertebral osteomyelitis and metastatic rare lesions chondroma and nerve sheath tumors. Imaging: • Prevertebral lesions anteriorly displace the retropharyngeal space and Retropharyngeal tuberculous abscess anterior border of the prevertebral muscles. CT demonstrates hypodense fluid collection involving the • Posteriorly displace the retropharyngeal space (Asterisks) posterior triangle fat. www.indiandentalacademy.com
Carotid space / Visceral vascular space • The cylindrical space extends from base of the skull to the aortic arch. • It is invested with all three layers of the deep cervical fascia Thrombosed internal jugular vein Left IJV fails to fill with contrast. The lumen is hypodense
Vascular complications: 1. Artery rupture – 20 to 40% mortality www.indiandentalacademy.com
2. Venous thrombosis – Life threatening problem
Complications of space infection Frontal view of the patient with right cavernous sinus thrombosis
• Venous congestion of the fundus of the left eye. • the same patient two weeks later. Clinically One eye experiences early involvement than the other. www.indiandentalacademy.com
Cranial nerve most likely to be involved is abducens.
Diagnosis of cavernous sinus thrombosis • Eagleton’s six features. – Known site of infection. – Evidence of blood stream infection. – Early sign of venous obstruction in retina, conjunctiva or eyelids. – Paresis of III, IV, VI cranial nerves resulting from inflammatory edema. – Abscess forms and neighboring tissues and – Evidence of meningeal irritation. www.indiandentalacademy.com
• Venous drainage of the head including the dural sinuses.
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Mediastinitis
• Extension of infection from deep neck spaces into the mediastinum is heralded by – – – –
chest pain severe dyspnea Unremitting fever, Radiographic demonstration of mediastinal widening. www.indiandentalacademy.com
Surgical incisions used to approach deep neck infections
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Diagnostic Imaging of Fascial & Neck Spaces Plain film.
CT.
MRI
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Ultrasound
Plain Film • Diagnostic imaging of a patient with a known or suspected fascial space infection often starts with a plain film study of pharyngeal or cervical airways. • Views taken
AP view
– AP view – Lateral view
• Plain film findings: - In the AP view the normal cervical airway should appear symmetrical over the middle third of the cervical spine. - It should have distinct shoulders in the proximal segment of the trachea. - Lateral view – In the adult the width of the prevertebral soft tissue should not exceed 7mm at the C3 level and 20mmwww.indiandentalacademy.com at C7 level.
Lateral view
Ultrasound • Not been used extensively in the evaluation of inflammatory lesions involving the H & N. • Major limitation is it cannot penetrate osseous structures such as maxilla/mandible. • Useful in differentiating between solid and cystic masses and in demonstrating the relationships of these masses to various structures. • An echomorphological classification of soft tissue head and neck swelling, consisting of edema, infiltrate, preabscess echo-poor and echo-free abscess, has been reported.
US of submandibular region demonstrating a branchial cleft cyst
US of Rt parotid showing an www.indiandentalacademy.com echogenic shadowing sialolith in hilus of Rt parotid
Principles of incision and drainage • Incise in healthy skin and mucosa when possible. • Incision placed at the site of maximum fluctuance results in a puckered, unesthetic scar. • Place the incision in an esthetically acceptable area. • When possible place the incision in a dependent position to encourage drainage by gravity. • Dissect bluntly with closed surgical clamp or finger, through deeper tissues. • Place a drain and stabilize it with sutures. www.indiandentalacademy.com
Principles of incision and drainage • Consider use of through and through drains in bilateral submandibular space infections. • Do not leave drains in place for an overly extended period. • Remove them when drainage becomes minimal. • Clean wound margins daily under sterile conditions to remove clots and debris. • Another approach to drainage is the use of computed tomographic (CT) guided catheter. www.indiandentalacademy.com
Computed Tomography – Guided Percutaneous Drainage of a Head and Neck Infection – JOMS 1992 Left submandibular space abscess
Percutaneous needle being guided into the abscess www.indiandentalacademy.com
Radiopaque markers on the skin
Aspiration to evacuate the abscess
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