Download Paranasal Sinus Anatomy

Paranasal Sinus
Anatomy
Marilene B. Wang, MD,
FACS
Professor
UCLA Division of Head and Neck
Surgery
Chief of Otolaryngology
VA Greater Los Angeles Healthcare
System
Paranasal Sinus Function
„ Lining
– pseudostratified
ciliated columnar epithelium
„ Mucous and serosanguinous
glands
„ Parasympathetic and
sympathetic innervation
Paranasal Sinus Function
„ Mucous
blanket renewed every
10-15 minutes
„ Warm and humidify air
„ Secrete immunoglobulins,
interferons, inflammatory cells
Paranasal Sinus Function
„ Cilia
beat 10-15 times/second
„ Cilia function varies with
environment, allergies, smoking,
etc.
„ Mucociliary system—cleanse sinus,
immunoprotective
„ Move mucous to natural ostia of
sinuses
Four Paired Sinuses
„Ethmoid
„Maxillary
„Frontal
„Sphenoid
Ethmoid Sinus
„ Greatest
anatomic variation
„ Pyramidal shape with base
posteriorly
„ 4-5 cm length A-P
„ 2.5 cm height
„ 0.5 cm wide anteriorly
„ 1.5 cm wide posteriorly
Ethmoid Sinus
„Numerous
small air cells
„Filled with fluid at birth
„Visualized at 1 year of
age
Ethmoid Sinus
„ Roof---fovea
ethmoidalis
„ Lateral wall—lamina
papyracea
„ Average 9 air cells
„ Anterior group
„ Posterior group
Anterior Ethmoid Cells
„ Frontal
recess
„ Infundibular
„ Bullar
„ Conchal
„ Agger nasi
Posterior Ethmoid Cells
„ Onodi
cells—surrounding optic
nerve within sphenoid bone
„ Posterior ethmoid artery—junction
of fovea ethmoidalis and frontal
bone, anterior to optic nerve
„ Anterior ethmoid artery—dome of
ethmoid posterior to frontal recess
Middle Turbinate
„ Conchal
cell (concha
bullosa)
„ Attached superiorly to the
cribriform plate
Middle Turbinate
„ Attached
to ethmoid
capsule and lamina
papyracea by basal lamellae
„ Posterior end at
sphenopalatine foramen
Maxillary Sinus
„ Present
at birth
„ Rapid growth age 0-3, then
7-12
„ Triangular shape
„ Natural ostium superior
medial wall
Frontal Sinus
„ Not
present at birth
„ Forms by age 12
„ Anterior and posterior table
„ Nasofrontal duct—
misnomer
„ Frontal recess
Frontal Recess
„ Connection
of the frontal
sinus to the anterior
ethmoid
„ Term first used by Killian in
1898
Frontal Sinus
„ Van
Alyea—performed 247
cadaver dissections in 1930s
„ Used the term “frontal recess”
„ Warned of various cells
obstructing it
„
Van Alyea DE. Archives of Otolaryngol 29:881901, 1939
Frontal Sinus Embryology
„4
frontal pits—form frontal and
ethmoid sinuses
„ 1st pit—Agger Nasi cell
„ 2nd pit—Frontal Sinus
„ 3rd pit—other ethmoid cells
„ 4th pit—other ethmoid cells
Schaeffer JP, Amer J Anatomy 1916
Kasper, Archives of Otolaryngol, 1936
Sphenoid Sinus
„ Evagination
of sphenoethmoid
recess at birth
„ Pneumatization begins age 3
„ Reaches sella by age 7
„ Development continues
through adulthood
Sphenoid Sinus
„ 20
mm high, 23 mm deep, 17
mm wide
„ Vessels and nerves on lateral
aspect (internal carotid artery,
optic nerve, vidian nerve)
Sphenoid Sinus
„ Dehiscent
or minimal bony
covering over vessels and
superior wall (dura)
„ Intersinus septum rarely
midline
„ Caution—intersinus septum
often inserts onto carotid canal
Sphenoid sinus—3
types
„Conchal
„Presellar
„Sellar
Sphenoid Sinus
Distances
„ From
Anterior Nasal Spine
„ To Sphenoid Ostium 7 cm
„ To
Pituitary Fossa
8.5 cm
Key Anatomic Landmarks
in the Nose and Paranasal
Sinuses
„ Middle
turbinate
„ Lamina papyracea
„ Ethmoid fovea
„ Cribriform plate
„ Sphenoid
Endoscopic Dissection
„ Nasal
endoscopy
„ Identify turbinates, uncinate, bulla
„ Uncinectomy, middle meatal antrostomy
„ Anterior ethmoidectomy, identify lamina
papyracea, skull base, anterior ethmoid
artery
Endoscopic Dissection
„ Posterior
ethmoidectomy, identify skull
base, posterior ethmoid artery, anterior
sphenoid, superior turbinate
„ Sphenoid sinusotomy, identify optic
nerve, carotid, sella, V2
„ Frontal recess dissection, identify agger
nasi
Draf Procedures (I-III)
„
„
„
Type I—removal of disease inferior to
frontal sinus ostium
Type IIA—Removal of ethmoid cells
projecting into the frontal sinus;
IIB—Removal of frontal sinus floor from
the lamina papyracea to the nasal
septum
Type III—removal of bilateral floor with
superior nasal septum and intersinus
septum (EMLP)
Endoscopic Modified
Lothrop Procedure
„ Lothrop—1914
described
external ethmoidectomy
approach through which he
removed the intersinus septum
and floor of the frontal sinus
EMLP
„ Close
(1994) and Gross (1995)
described a modification through a
transnasal endoscopic approach
„ Not a functional procedure since it
disrupts the normal mucociliary
clearance from the frontal sinus
EMLP--Indications
„ Medically
refractory chronic
frontal sinusitis
„ Failure of intranasal frontal
sinusotomy or more
conservative techniques
„ No identifiable bony remnants
in the frontal recess
EMLP--Results
„ Variable
results
„ Ostial patency rates 82-95%
„ Complications
Bleeding
„ Scarring/Stenosis
„ Orbital
„ Intracranial
„
Advanced Dissection
„ Endoscopic
DCR
„ Modified Lothrop
„ Orbital decompression
„ Optic nerve decompression
„ Sphenopalatine artery ligation
April 29, 2009
Dissection Course
Endoscopic Sinus Dissection
1-4 PM
Facial Plastic Dissection
4-7 PM
Dinner at Napa Valley Grille
7:00 PM