2. INTRODUCTION
• The cervical fascia invests muscles and organs of the neck, limiting and
influencing the direction of spread of infection.
• The cervical fascia is divided into two layers: the superficial layer that
envelops platysma and the muscles of facial expression and the deep
layer, which, in turn, comprises superficial, middle and deep layers.
• Superficial (or investing) layer of deep cervical fascia
• attached superiorly to the superior nuchal line of the occipital bone, the
mastoid process, the zygomatic arch, the inferior border of the mandible,
the hyoid and the spinous processes of the cervical vertebrae.
• inferiorly to the manubrium, the clavicle and the acromium and spine of
the scapula
• forms the roof of the anterior and posterior triangles of the neck
• forms the most superficial fascial boundary of the deep neck spaces
• provides a robust barrier to the spread of infection, such that abscesses
tend to track deep to it into adjacent, deeper neck spaces, or even into the
mediastinum.
3. • Middle layer of deep cervical fascia (or pre-tracheal
fascia)
• limited to the anterior aspect of the neck limited to the anterior aspect of the
neck
• splits to invest the thyroid gland, trachea and oesophagus and blends with the
carotid fascia laterally
• descends into the superior mediastinum where it blends with the fibrous
pericardium.
• Consequently, it bounds a deep space which extends from the neck into the
mediastinum
• Deep layer of deep cervical fascia (prevertebral fascia)
• forms part of a fascial sleeve for the prevertebral muscles that surround the
vertebral column.
• extends from the skull base to the third thoracic vertebra where it fuses with
the anterior longitudinal ligament in the posterior mediastinum
• extends laterally as the axillary sheath.
• Alar fascia
• component of the deep layer of deep cervical fascia although it is described
separately from it as it lies between the deep and middle layers of deep
cervical fascia
4.
5. NECK SPACES
• Parapharyngeal space (lateral pharyngeal space, pharyngomaxillary
space)
• forms an inverted cone, base bounded by the petrous portion of the
temporal bone, apex at the level of the hyoid.
• crossed by the styloid process and attachments thus dividing the space
into pre and post-styloid compartments.
• The pre-styloid compartment (anterior to the styloid complex) contains
fat, connective tissue, the maxillary artery, the inferior alveolar nerve, the
lingual nerve and the auriculotemporal nerve.
• the post-styloid (posterior) compartment contains the carotid sheath and
its contents, the glossopharyngeal and hypoglossal nerves, the
sympathetic chain and associated lymph nodes.
• can become infected either primarily or as a consequence of direct spread
of infection from the submandibular and/or the retropharyngeal spaces.
• A recent study of DNSIs of this space in particular demonstrated different
clinical features depending on whether the anterior or posterior
parapharyngeal space (APPS and PPPS respectively) is infected.
6. • The APPS contains fat which in the presence of infection may liquefy,
develop into pus and hence abscess formation.
• The PPPS is rich in lymph nodes and vessels. Infection in this space causes
lymphadenitis, but less likely to develop into abscess formation.
• more conservative approach possible in PPPS and aggressive surgical
drainage of pus required for APPS.
7. Retropharyngeal space
• contains lymph nodes.
• Bounded anteriorly by the middle layer of deep cervical fascia and posteriorly
by the alar fascia.
• Extends craniocaudally from the skull base to the tracheal bifurcation.
• Midline raphe is formed by the attachment of the superior constrictor muscles
to the alar fascia.
• Retropharyngeal space abscess
• Usually in adults by penetrating trauma through the posterior mucosal wall of
the pharynx or cervical esophagus.
• in children, secondary to suppuration of retropharyngeal lymph nodes
following an upper respiratory tract infection, although retropharyngeal lymph
nodes tend to regress after the age of 5 years.
• a significant cause of airway compromise, and as a consequence surgical
tracheostomy is not commonly required.
• Once the airway has been appropriately secured the abscess can be drained in
a controlled fashion.
• The incision is made at the most inferior aspect of the collection such that
further accumulation of pus will drain through gravity into the pharynx.
8.
9. So-called ‘danger space’
• The so-called ‘danger space’ is a potential space between the alar fascia
anteriorly and the deep layer of deep cervical fascia (prevertebral fascia)
posteriorly, which extends craniocaudally from the skull base to the
diaphragm.
10. Submandibular space
• Cranially by floor of mouth mucosa
• Laterally by Mandible
• Anteroinferiorly by the anterior belly of digastric
• Posteroinferiorly by the posterior belly of digastric
• The mylohyoid muscle lies anteriorly and the stylomandibular ligament
posteriorly.
• The space is divided by the mylohyoid muscle into sublingual and
submandibular compartments
• These compartments are continuous around the posterior free edge of the
mylohyoid muscle and the submandibular gland lies within both as it straddles
this free edge.
• Ludwig’s Angina
• Acute infection of bilateral sublingual and submandibular spaces, and the
submental space.
• occurs most commonly as a consequence of anterior dental infection.
• Gross oedema of the floor of mouth and of the anterior tongue, such that the
tongue becomes grossly swollen, protuberant and immobile.
• The result is significant risk of life-threatening airway obstruction
• Emergency tracheostomy, a primary treatment option.
11.
12.
13. Masticator space
• lies inferior to the skull base
• Bounded by the pharyngeal mucosa medially and the medial surface of
the ramus of the mandible laterally.
• The lateral pterygoid plate, superior constrictor, tensor and levator palatini
muscles constitute the posteromedial border and can be subdivided into
superficial temporal space superolaterally, deep temporal space
superomedially, pterygoid space inferomedially and masseteric space
inferolaterally.
• Communication with the pterygopalatine fossa exists via the
pterygomaxillary fissure
• The muscles of mastication and the mandibular division of the trigeminal
nerve are contained within it.
• Masticator Space Infection
• usually arises secondary to odontogenic infection
• Less commonly as spread from infection from the parotid space,
submandibular space or peritonsillar space.
• Trismus due to oedema of the adjacent pterygoid muscles.
14.
15. Visceral space
• formed anteriorly by the middle layer of deep cervical fascia
• Posteriorly by the deep layer of deep cervical fascia
• contains the larynx, hypopharynx, cervical oesophagus, proximal trachea,
thyroid and parathyroid glands.
• Suppurative Thyroiditis
• due to abnormal development of the 4th branchial pouch
• results in a communicating sinus between pharynx and thyroid bed
• in some cases, a proximal orifice may be identified as a defect in the
mucosa of the piriform fossa.
• Barium swallow examination and/ or cross-sectional imaging with
contrast-enhanced CT or MRI may demonstrate the sinus tract, and the
orifice will usually be identifiable by careful inspection of the piriform
fossa mucosa under anaesthetic using direct pharyngoscopy.
• Preponderance for the left side of the hypopharynx.
• Treatment:- excision of the sinus tract including the ipsilateral hemithyroid
• Alternatively, obliteration of the sinus opening in the hypopharynx using
monopolar diathermy.
16. Carotid space
• Formed by the carotid sheath
• Carotid Sheath formed from all three layers of deep cervical fascia
blending together.
• contains the common carotid artery, the internal jugular vein (IJV) and the
vagus nerve
17. Parotid space
• formed by the superficial layer of deep cervical fascia
• splits to invest the parotid gland
• therefore also contains the facial nerve, the retromandibular vein, the
external carotid artery and its terminal branches.
18. Peritonsillar space
• lies lateral to the pharyngeal tonsil
• Medial to the superior constrictor muscle.
• contains loose connective tissue
• Site of accumulation of pus in peritonsillar abscess, or quinsy.
• direct communication exists between the posterior aspect of the
parapharyngeal space and the retropharyngeal space, as well as the
anterior parapharyngeal space and the submandibular space.
• peritonsillar space abscess can directly spread to the parapharyngeal
space by direct extension, via lymph and/or blood vessels which traverse
the superior constrictor muscle.
19.
20. Aetiology of DNSI
• odontogenic infection most common aetiological factor causing 31–49% of
DNSIs.
• Peritonsillitis in approximately 7–20% of cases
• Whilst in 17– 57% of cases, the primary source of infection is not clinically
apparent
• Ingestion of foreign body, coexisting Diabetes Mellitus (DM), Human
Immunodeficiency Virus (HIV) infection and intravenous (IV) drug abuse
• Mycobacterial infection, mandibular fracture, sialolithiasis, parotitis and
thyroid infection
21. • Pain, pre-eminent symptom in most patients
• Pain, at the neck space harbouring the infection, but can also be referred
to the ear, cause odynophagia, trismus or torticollis.
• Other symptoms:- dysphonia, dysphagia, sialorrhoea or cough.
• swelling in the neck, pyrexia and trismus.
• Skin fistulae, medial or anterior displacement of the lateral or posterior
pharyngeal wall and gingival swelling.
• Sex:- male to female ratio is 1.6:1
• Age:- 20-40 years
• Coexistent diseases:- dental caries, DM, IV drug abuse and HIV infection.
Clinical Features
22. Clinical Assessment and Investigations
• full clinical history, a thorough examination including fibre-optic
nasoendoscopy to assess the upper aerodigestive tract mucosa and airway
patency simultaneously.
• Due to the potential for DNSIs to cause significant airway compromise it is
essential that the initial assessment of patients is performed with high
priority.
• Pulse rate, blood pressure, temperature. sPO2, respiratory rate
• urea, creatinine and electrolytes assays, blood count, including differential
white cell count, C-reactive protein and erythrocyte sedimentation rate.
• Pustulating skin fistulae and obviously infected dental sockets or roots
may be swabbed for microbial cultures but routine pharyngeal
microbiology swabs must not be taken to avoid precipitating an airway
crisis as a consequence of triggering the gag reflex.
23. • Contrast-enhanced CT:- gold-standard imaging modality
• Due to potential communication of the visceral, retropharyngeal, danger
and prevertebral spaces with the mediastinum it is imperative to include
the mediastinum in the CT scan field.
• Where there is clinical concern of septic emboli spreading to the brain,
lungs or liver these organs are required to be imaged also.
• Abscesses:- characteristic rim enhancement on CT imaging
• Cellulitis:- fluid and fat stranding in the subcutaneous tissues and along
fascial planes
• Myositis:- enlargement and hyperenhancement of the adjacent
musculature
• Ultrasound:- whether an abscess has sufficiently liquified to be drained,
targeting attempted drainage.
• Orthopantomogram:- infection of dental origin
24. Microbiology and Pharmacology
• Peptostreptococcus spp., Viridans Group Streptococci,
Staphylococcus aureus, Staphylococcus epidermidis
and Klebsiella pneumoniae
• Typically, broad-spectrum antibiotics are commenced
prior to receipt of microbiological results,
• Polymicrobial cultures are commonly seen.
• amoxicillin/clavulanate, or 2nd or 3rd generation
cephalosporins with metronidazole
• Clindamycin and vancomycin are commonly used as
second-line agents, or potential first-line agents when
drug allergy or sensitivity restrict choice.
25. Surgical Treatment
• Neck space infection:- life threatening infection
• Crude mortality rates of up to 2%.
• Ensure protection of the airway primarily, consider surgical drainage of
pus secondarily.
• conservative management wherever possible
• Without impending airway compromise, surgical intervention follows a
period of conservative management of 24–48 hours
• Conventional surgical drainage procedures:- incise the skin over the area
of maximal fluctuance or induration
• Following evacuation of the abscess contents, the abscess wall is curetted,
and any loculations or boundaries between adjacent and communicating
neck spaces (e.g. retropharyngeal, parapharyngeal and submandibular)
are broken down – often with digital dissection
• In classical Ludwig`s angina:- multiple transcutaneous stab incisions
26. • Drains are secured to permit further drainage of pus
• The underlying dental infection should be dealt with during the same
general anaesthetic
• ultrasound-guided aspiration of pus.
27. Airway Management
• Maintaining a patent and safe airway is the pre-eminent step
• Mortality due to asphyxiation, hypoxia, delayed septic complications
• The widespread use of antibiotics has reduced the morbidity and mortality
from pharyngeal oedema, permits a watch and wait policy in selected
cases.
• large abscesses causing a precarious airway:- secure the airway prior to
surgical drainage, maintain the airway post-operatively.
• Conventional endotracheal intubation is not always possible due to
trismus, reduced neck extension, laryngopharyngeal oedema, mass effect
from the abscess and the friable nature of the mucosa
• Airway secured via Tracheostomy.
28. Complications
• Tracheostomy, either planned or ‘crash’, is reported as necessary in 3–22%
of patients
• patients with Ludwig’s and retropharyngeal abscess:- higher risk of airway
obstruction than those presenting with lateralized abscesses
• Other complications:- pneumonia, IJV thrombosis, carotid artery
aneurysm and rupture, necrotizing fasciitis, skin fistulae and defects, vocal
cord and facial palsies, descending mediastinitis, upper gastrointestinal
bleeding, iatrogenic bleeding following tracheostomy insertion, septic
emboli from IJV thrombosis, sepsis, multi-organ failure and death.
• Patients with pre-existing comorbidities are more likely to suffer from
complications, as are patients that have infection in more than two neck
spaces
29. Paediatric Neck Space Infections
• more often results from an upper respiratory tract infection than from
odontogenic aetiologies
• methicillin-resistant Staphylococcus aureus (MRSA) is more frequently
isolated from pus samples
• The management is the same as that in adults.
