Surgical Anatomy of Scalp Flashcards
SCALP
Hair-bearing skin and subcutaneous tissue covering the
neurocranium
•From the occipital bone → Supra-orbital margins on the
frontal bones
•Extends over temporal fascia → zygomatic arches
•5 LAYERS of SCALP
1st three layers → intimately connected and function as UNIT
S – SKIN
o Thin (except in occipital region) o Contains many sweat and sebaceous glands and hair follicles o ↑ arterial supply o Good venous and LN drainage
C – CONNECTIVE TISSUE
o Thick, ↑ vascularized subcutaneous layer
o ↑ cutaneous nerves
A – APONEUROSIS
o A.k.a. EPICRANIAL APONEUROSIS/EPICRANIUM o Broad, strong tendinous sheet o Covers calvaria and attachment for muscle bellies converging from: Forehead and occiput (Occipitofrontalis Muscles) Temporal Bones (Temporoparietalis and Superior Auricular Muscles)
Frontal Belly of
Occipitofrontalis
Pulls scalp anteriorly,
wrinkles forehead, raises
eyebrows
Superior Auricular Muscle
part of temporoparietalis
Elevates auricle of
external ear (wiggle the
ears)
SCALP PROPER = First 3 Layers of the Scalp
•Clinically regarded as a single layer
•Remain together when scalp flap is made
surgically/avulsed
L – LOOSE AREOLAR CONNECTIVE TISSUE
o Spongy layer
o Allows free movement of the scalp proper over the calvaria
o Has potential spaces that may distend with fluid (injury/infection)
P – PERICRANIUM
o Dense Layer CT o Forms external periosteum of the neurocranium o Firmly attached, can be stripped off in vivo except at attachments to cranial sutures
BLOOD SUPPLY OF THE SCALP
Highly vascularized, vessels anastomoses freely
Blood vessels arises from anterior, lateral, and
posterior scalp regions
Blood vessels to the scalp supply little blood to
the calvaria
o CALVARIA is supplied by the MIDDLE
MENINGEAL ARTERIES
Loss of scalp does not produce necrosis of the
calvarial bones
ARTERIES of Scalp
INTERNAL CAROTID arteries → OPHTHALMIC arteries o Supratrochlear arteries o Supraorbital arteries EXTERNAL CAROTID arteries o Posterior auricular arteries o Occipital arteries o Superficial temporal arteries
Venous Drainage of S
Supratrochlear veins Supraorbital veins Superficial temporal veins Posterior auricular veins Occipital veins
Epicranial Aponeurosis is strong
Prevents superficial scalp wounds from gaping
Holds margins of the wound together
Does not need deep sutures
Deep Scalp Wounds
Gape widely when aponeurosis is lacerated in coronal plate
From pull of frontal and occipital bellies of occipitofrontal muscle in A-P direction
LOOSE CONNECTIVE TISSUE (Layer 4)
Danger area of the scalp – fluid can collect
Pus/blood spreads easily
Infection spreads → cranial cavity from emissary
veins → calvaria → meninges
Infection is limited by
Occipitofrontalis muscle attachment at neck
Temporal fascia at zygomatic arches
Occipitofrontalis muscle inserts into skin and SQ
o Fluid can enter eyelids and root of the
nose
o Even slight injury/inflammation → ↑fluid
in periorbital region
o Fluid collection should be limited
laterally and posteriorly, but flows easily
anteriorly
PERIORBITAL ECCHYMOSSES:
“black eyes”,
can result from injury to scalp and/or forehead.
o From extravasation of blood into SQ and skin
SCALP LACERATIONS
Most common type of head injury requiring surgical care
Bleed profusely
Arteries entering periphery of scalp bleed from both ends (from anastomoses)
o Do not retract, held open by dense CT
layer
o Occipitofrontalis muscle spasms ↑ wound gape open if 3rd layer is injured
SCALP INJURIES
Arteries arising at sides of head area wellprotected by dense CT
o Anastomose freely
Partially Detached Scalp/avulsed scalp injuries
common among motorbike vehicular accidents can
be replaced with good healing if 1 vessel supplying
scalp is intact
SCALP INCISIONS
ATTACHED CRANIOTOMY
Surgical removal of calvarial segment + soft tissue
scalp
Incisions are made convex and upward
SUPERFICIAL TEMPORAL ARTERY is included
in tissue flap
CEPHALHEMATOMA
Bleeding between the baby’s pericranium and
calvaria → blood trapped
Usually over parietal bone
Will resolve on its own without interventions
After difficult delivery
o Birth trauma that ruptures multiple minute
periosteal arteries to the calvaria → fluid
collection under the scalp
CRANIUM
a.k.a. SKULL Skeleton of thehead Most complicated bony structure in the human body 28 INDIVIDUAL BONES: o 11 = paired o 6 = single 2 PARTS: o NEUROCRANIUM (protects thebrain) o VISCEROCRANIUM (skeleton in the face)
THE EAR
Organ of hearing and balance
AURICLE
Collects air vibrations
Thin plate of elastic cartilage covered by skin
Possesses extrinsic & intrinsic muscles
N: Facial Nerve
TEMPORAL BONE (2)
o Help form the base and lateral walls of the skull
o Contain auditory and vestibular apparatuses
o Contain mastoid air cells
PARTS of Temple
o Squamous
o Petrous
o Tympanic
o Styloid
TEMPORAL BONE FRACTURES
o Occur in 1/5 of the skull fractures
CAUSE of TBF
Blunt trauma (VA/Assault)
GSW (gunshot wound)
DIAGNOSIS of TBF
Cranial CT
2 PATTERNS of TBF
Longitudinal and Transverse
Longitudinal TBF
s (80%): Associated with: o Lateral Skull Trauma o Facial Nerve Injury (20%) S/SX o Conductive hearing loss o Ossicular Injury o Bloody Otorrhea (ear discharge) o Labyrinthe Concussion
Transverse TBF
(20%): From fronto-occipital trauma Associated with: o (+) Facial nerve injury (50%) o (+) Otic capsule injury
S/SX: Sensorineural hearing loss, ↓ vestibular function, hemotympanum, CSF leak in the nose or ears
Oblique TBF
– combination of the
two patterns; most fractures in
practice
FACIAL NERVE STATUS
Most significant in management (+) Delayed/Partial Paralysis → usually resolve in 1 week, with conservative management
INDICATIONS FOR SURGERY of TB
Persistent facial nerve paralysis after 1 week post injury → Nerve Decompression >90% degeneration >72 hours after onset of complete paralysis
SURGICAL TREATMENT of TBF
Facial Nerve Decompression o If persistent, may have to sacrifice hearing Manage any severe intracranial/vascular injuries first Protect the eye from desiccation o (-) blink reflex o Artificial tears, lubricant eye taping
PTERION
Junction between sphenoid, squamous
temporal, frontal and parietal bones
2 fingerbreadths superior to zygomatic
arch
Thumb’s breadth posterior to frontal
process of zygomatic bone
Overlies the frontal branches of the middle meningeal vessels
Hard blow to side of head → fracture →
rupture frontal branch of middle
meningeal artery or vein
Bleed from middle meningeal artery →
EPIDURAL HEMATOMA
Hematoma exerts pressure on underlying cerebral cortex
White concave lesions (blood) seen on CT scan that reflects the shape of the epidural hematoma
It causes brain herniation wherein, it
pushes the brain parenchyma to one side
and the brainstem herniates downward to
the foramen magnum
LANDMARKS OF AURICLE
Helix Crura Anti-Helix Concha Tragus Antitragus External Acoustic Meatus Lobule of the Auricle
AURICULAR LACERATIONS
Carefully align Helical Rim & Antihelix
o Apply pressure dressing
Repair injuries so that cartilage is covered
o Cartilage has no intrinsic blood supply & is susceptible to ischemic necrosis
o Suture should be passed through
perichondrium but NOT cartilage itself!
o Suture the skin not the cartilage, no
vessels, may necrose
o Injuries are usually from earrings
AURICULAR HEMATOMA
Occurs after injury / laceration Prompt drainage with needle And most importantly, apply pressure dressing with bolus dressing so to prevent the fluid from accumulating again usually: - Recording: 24 hours at least - Old trans: at least 3 days - Book: at least 4 days
EXTERNAL AUDITORY MEATUS
Curved tube that leads from auricle to tympanic membrane
lined by skin
conducts sound waves from auricle → tympanic membrane
outer 1/3: cartilage
lined with hairs, sebaceous glands & Ceruminous glands (modified sweat glands) – glands that make your earwax
inner 2/3: bone (tympanic plate)
N: Auriculotemporal nerve
Auricular branch of vagus nerve
LN: Superficial parotid, mastoid & superficial cervical LN
OTOSCOPIC EXAMINATION
Straighten EAM by gently pulling auricle:
upward and backward (adult)
backward and downward (infant)
Tympanic membrane is pearly gray & concave
Adult EAM
length = 2.5 cm
narrowest 5 mm from the tympanic membrane
EAR INFECTIONS
May involve external, middle, or internal ear
May follow an acute / chronic course → otological & intracranial complications
OTITIS EXTERNA
Infection of skin in EAC
Acute / chronic course
ACUTE OTITIS EXTERNA / SWIMMER’S EAR
Moisture in EAC after swimming remains→ skin
maceration & itching → scratching → erodes the skin
most common organism →
Pseudomonasaeruginosa
if prolonged, may result in Chronic Otitis Externa
CHRONIC OTITIS EXTERNA
Profound itching for prolonged periods (months to years) → gradual thickening of EAC skin
MALIGNANT OTITIS EXTERNA
Fulminant necrotizing infection of otological soft tissues Osteomyelitis of temporal bone PX: Diabetes mellitus, elderly,immunodeficient SX/ SYMPTOMS: o (+) Cranial nerveneuropathy o Persistent otalgia > 1 month o Purulent Otorrhea x several weeks o Classic PE Finding = (+) granulation tissue along EAC Floor
Complications of MOE
Complications:
o Progress to involve skull base, soft
tissue → meningitis → brain abscess →
death
treatment of MOE
Treatment: o IV Antibiotics vs Pseudomonas o Wound GS/CS o Surgical Debridement – if no response to medical management
MIDDLE EAR
Air-containing cavity in the petrous part of the temporal
bone (from Tympanic Membrane → Oval window)
Lined with mucous membrane
Contains ossicles
Narrow, slit-like cavity
TYMPANIC MEMBRANE
Thin, fibrous, pearly gray membrane
Obliquely placed (Down, forward, and lateral)
Circular, 1cm in diameter
Extremely sensitive to pain
UMBO - Small lateral depression, from tip of the
handle of the malleus
CONE OF LIGHT- radiates anteroinferiorly from
umbo; the otoscope is used
PARS FLACCIDA
Small triangular area bounded by
folds
PARS TENSA
Tense remainder of membrane
Nerve supply of ME
Auricotemporal nerve, Aurical branch of Vagus Nerve
OSSICLES
Smallest bones in the human body Transmit vibrations of the tympanic membrane (eardrum) to perilymph of the inner ear MALLEUS (Hammer) INCUS (Anvil) STAPES (Stirrup)
AUDITORY TUBE / EUSTACHIAN TUBE
Connects anterior wall of the tympanic membrane
cavity to nasal pharynx
Posterior 1/3 = bony
Anterior 2/3 = Cartilaginous
Equalizes air pressures in tympanic cavity and nasal
pharynx
In children, Eustachian tube is shorter and more
horizontal which makes them more prone to infections
in the middle ear
MASTOID ANTRUM
Behind the middle ear in the petrous part of the
temporal bone
bony pocket filled with air
Communicates with the middle ear by aditus
MASTOID PROCESS
Begins to develop during 2 year of life
MASTOID AIR CELLS
Series of communicating cavities within the process that
are continuous above with the antrum and the middle
ear.
Lined with mucous membrane
OTITIS MEDIA
Bacterial infection of the Middle ear
Ascending infection for the URTI via Auditory tube from nasopharynx
Acute redness, infection, bulging and fluid accumulation behind your tympanic membrane
ACUTE OTITIS MEDIA
Bacterial infection of the middle ear (< 3 weeks) Most common bacterial infection of the childhood (25%) ASSOCIATED WITH: o < 2 years old o From immaturity of the Eustachian tube –straight, while in adults -oblique o Craniofacial conditions (e.g. Cleft Palate) o Chronic URT
S/SX of AOM
o Otalgia (Ear pain) –due to pressure build up o Fever
PHYSICAL EXAM of AOM
o Bulging, opaque tympanic membrane
Most common organisms of AOM
o Streptococcus pneumonia
o Haemophilus influenza
o Morazella cattarrhalis
Treatment of AOM
o Oral antibiotics for systemic absorption, otic drops won’t penetrate tympanic membrane Amoxicillin Sulfadrugs Cephalosporin Macrolides (+) Tympanic membrane perforation → will heal spontaneously
SUBACUTE OTITIS MEDIA
Otitis media lasting 3-8 weeks
From unresolved acute otitis media
CHRONIC OTITIS MEDIA
Otitis media > 8weeks Same symptoms Chronic inflammation and hypersecretion by middle ear mucosa
Associated with COM
with: Eustachian tube dysfunction Ciliary dysfunction Viruses/allergies Non-healing tympanic membrane perforation o Erosion of the ossicles
Symptoms of COM
Otalgia
Middle Ear fullness
Conductive hearing loss
Physical exam of COM
Retracted, opaque, tympanic membrane
(+) air fluid levels / bubbles
Treatment of COM
Removal of the debris under otomicroscopy Keep ear dry Topical antimicrobials: o Neomycin/ Polymixin / Quinolone + Steroids o 2ºAcetic acid – for mixed bacterial + fungal infections
INTRATEMPORAL /
OTOLOGIC
COMPLICATIONS
Acute coalescent mastoiditis Petrotitis (infection of the petrous bone) Facial Nerve Paralysis (CN VII passes underneath this structure) Labyrinthitis
INTRACRANIAL
COMPLICATIONS
Otologic meningitis (most common) – Patients come in with neurologic dysfunction. CT scan shows brain abscesses and is usually from a chronic infection Epidural/subdural abscess Brain abscess Otitic hydrocephalus Sigmoid sinus thrombophlebitisInfection channeling in to the blood vessel
ACUTE MASTOIDITIS
Spread of infection from otitis media into the
mastoid antrum and mastoid air cells which
is right behind the brain.
May spread beyond middle ear to meninges
and temporal lobe of the brain →
Meningitis and cerebral abscess
Spreads to facial nerve and inner ear →
Facial nerve palsy, labyrinthitis, vertigo
Destruction of bony lamellae secondary to
acute purulent process
Reddish discoloration and tenderness
behind the ear
Mastoid cells coalesce → form 1
common space filled with pus
S/Sx
o Pain, fever
o Swelling behind the
ear
Treatment of AM
o Myringotomy + Tube placement •To remove effusion and ventilate middle ear o Topical drugs – for otorrhea o Tympanoplasty – for non-healing tympanic membrane perforations o Reconstruction of ossicular chain o Mastoidectomy
INNER EAR (LABYRINTH)
Working part of the Ear Neurologic 2 Parts: o Bony Labyrinth o Membranous Labyrinth
BONY LABYRINTH
￮Series of cavities within the petrous bone
￮Cavities of dense bone that contain PERILYMPH
(which suspends the membranous labyrinth)
￮3 PARTS:
o VESTIBULE (entrance hall)
o SEMICIRCULAR CANALS
o COCHLEA (Snail shell)
MEMBRANEOUS LABYRINTH
- Series of membranous sacs with bony labyrinth
- Lodged within the bony labyrinth
- Filled with ENDOLYMPH
- Surrounded by Perilymph
•PARTS of Labyrinth
○UTRICLE and SACCULE
○3 SEMICIRCULAR DUCTS
○COCHLEAR DUCT
LABYRINTHITIS
Inflammation of the inner ear
SEROUS LABYRINTHITIS
Bacterial products/inflammatory mediators transudate → through round window → inner ear
SUPPURATIVE LABYRINTHITIS
Purulent bacterial infection extends →
inner ear → destroys sensory hair cells &
CN VIII → Meningitis
CHOLESTEATOMA
•Epidermoid cyst or infection of the middle ear &/or
mastoid through enzymes
•Destroys or erodes bone due to expansion &
enzymatic destruction
•ETIOLOGY
Retraction of squamous elements of
tympanic membrane into middle ear \ →
causes Eustachian tube dysfunction &
chronic otitis media
TREATMENT
MASTOIDECTOMY
if (+) chronic mastoiditis that
failed medical management/
develops cholesteatoma
OTOLOGIC MENINGITIS
•Most common intracranial complication of ear infections associated with Haemophilus Influenzae Type B
EAR & TEMPORAL BONE CA
•Uncommon, < 1% of all H&N malignancies
•Usually delayed diagnosis (You don’t you’re your
ears talaga everyday e, usually somebody else
points it out to you)
•Most common CA = Squamous Cell CA
If (+) involvement of middle ear & EAC = 50%
5-year survival rate
Pinna
most common for 1º CA because it
is the most common site of sun exposure
Petrous Bone
most common for
metastasis (breast, kidney, lung)
LIPS
2 fleshy folds that surround the oral surface outside = skin inside = mucous membrane Made of Orbicularis OrisMuscle Radiatefrom thelips intothe face
Landmarks of Lipa
- PHILTRUM: shallow vertical groove in midlineon
outer surface oftheupper lip - Vermillion Border
- Lateral Commissure- corners of your lips
- Cupid’s Bow
- Nasolabial Crease
Lip Injuries
- Close Orbicularis Oris in a separate layer
- Vermillion Border must be carefully approximated
- 1º Closure - done if injury involves 1/3 of width of lip, otherwise, might need flap or graft
Lip Cancer
Most common in Caucasian men (less melanin) 50-70
y/o
RISK FACTORS of LC
Prolonged sunlight exposure Fair complexion Immunosuppresion Tobacco use LN metastasis -> Submandibular & Submental LN (<10%) Most Common Sites: Lower lip (98%) Upper lip (2%) Oral Commissure (<1%)
Histology of LC
Squamous Cell CA (most common)
Basal Cell CA (more common in upper lip) – from shaving due to repetitive trauma
Kerato acanthoma, Verrucous CA melanoma,
minor salivary gland CA, sarcoma
Physical Exam of LC
l Exam
- Ulcerated lesion vermillion/ cutaneous
surface
- Palpation -> determine actual size & extent
of lesion
- Paresthesia adjacent to lesion – indicates
mental nerve involvement
Vestibule
•Slit-like space, communicates with exterior through oral
fissure between the lips
External: Between lips and cheeks
Internal: Between gums & teeth
•R&F: mucous membrane covering lips, cheeks & gums
Oral Cavity Proper
•Roof: Hard Palate (ant) & Soft Palate (post)
•Floor: Anterior 2/3 of the tongue + mucous membrane
of gums (gingiva
