understanding endoscopic anatomy of nose, paranasal sinus and anterior skull base-dr.rajat jain

1. 1
DR.RAJAT JAIN

2. ENDOSCOPIC EVOLUTION
2
 Endo’ – within ; ‘skopeein’– to see
 Optical device with lighting
 Used to look inside a body cavity, organ

3. Endoscopic anatomy divison
 Medial wall-septum
 Lateral wall
 3 turbinates- inferior (separate bone)
 middle
 superior
 3 meatus- superior meatus
 middle meatus
 inferior meatus
 Opening of various sinus
 Roof
 floor
 Blood vessels –anterior ethmoidal artery, sphenopalatine artery

4. 4
diagnostic nasal endoscopy
 A careful and methodical diagnostic endoscopy is the
key.
 Equipment
 Procedure
 Normal endoscopic findings
 Anatomical variations

5. 1st pass
 The 0 endoscope ( or 30 ) is passed along the floor
of nasal cavity between inferior tubinate and
septum.
 Septum – mucosa , spur or deviations.
 Inferior turbinate.
 Posterior choana.
 Posterior wall and roof of nasopharynx.
 Eustachian tube & fossa of rosenmullar.
 Inferior meatus – nasolacrimal duct opening.

6. 1ST PASS

7. Boundaries of posterior choanae
 anteriorly and inferiorly
by the horizontal
plate of palatine bone,
 superiorly and
posteriorly by
the sphenoid bone
 laterally by the medial
pterygoid plates.
 medially by the Vomer

8. 2nd pass
 Scope is passed along the floor upto posterior choana
and then moved upward medial to the middle
turbinate along the roof of posterior choana.
 Superior turbinate and meatus.
 Sphenoethmoidal recess.
 Sphenoid ostium lies 1- 1.5 cm above the roof of
posterior choana.
 Below ostium at the roof of posterior choana is mesh of
blood vessels – woodruf’s plexus.

9. 2ND PASS

10. 3rd pass
 Examine middle meatus.
 Gently retracting middle turbinate with freer’s
elevator or advance scope posteriorly and roll
the scope under inferior border of the middle
turbinate to enter posterior roomy part and
withdrawn from posterior to anterior .
 Uncinate process
 Bulla etmoidalis
 Groove btw these two – hiatus semilunaris
 Palpated with ballpoint goes into infundibulum.

11. 3RD PASS

12. NOSE
 Development nose – 4th to 8th week IUL.
 Nose
External nose
Internal nose

13. Nasal septum

14. Blood supply of nose

15. Inferior turbinate
 Independent bone.
 Straight course
 Inferior margin overhangs inferior meatus
 Inferior meatus having opening of NLD

16. Middle turbinate
 Projection from medial surface of ethmoidal
infundibulum.
 Divided into three parts depending upon –
attachment and orientation in 3D space.

17. Anatomical variations
 Ballooned up – concha bullosa .
 Superior meatus pneumatize vertical lamella –
interlamellar cell of Gurnwald.
 Paradoxically bent turbinate.

18. ANATOMICAL VARIATIONS

19. Middle meatus
 Lying lateral to middle turbinate.
 Recives drainage from frontal , maxillary, anterior
ethmoidal sinuses.
 Structures -
Uncinate process
Bulla ethmoidalis
Hiatus semilunaris
Infundibulum
Maxillary ostium
OSTEOMEATA L
COMPLEX

20. Uncinate process
 An uncinate process is a hook-shaped projection or
protuberance from a bone or organ.
 Uncinate process of ethmoid bone, a process located
in the nasal cavity

21. ANATOMIC VARIATION OF
UNCINATE

22. Ethmoidal air cells
 Anterior group-most prominent- bullae ethmoidalis
 Posterior group
 Separated by ground lamella

23. Agger nasi
cell
Pneumatization of
lacrimal bone
Forms a bulge
anterior to the
middle turbinate on
the lateral wall.

24. Ethmoidal bulla
 Well pneumatized , most constant, anterior ethmoidal
cell.
 Seperated posteriorly from ground lamella by recess –
retrobullar recess.
 Seperated from base of skull – suprabullar recess.
 Semilunar space – sinus lateralis of Gurnwald.
 Opens into middle meatus – hiatus semilunaris
superioris.

26. HALLER CELL
Haller cells are also
known as infraorbital
ethmoidal air
cells or maxilloethmoi
dal cells.
present in ~20% (range
2-45%) of patients
In most instances they
are asymptomatic

27. Anterior etmoidal artery
 Branch of ophthalmic
artery
 it accompanies
the nasociliary
nerve runs through
the ethmoidal canal to
supply the anterior and
middle ethmoidal
cells, frontal sinus, and
anterosuperior aspect of
the lateral nasal wall.

28. Anterior etmoidal artery
 When entering the cranium, it
gives off:
 a meningeal branch to the dura
mater.
 nasal branches. These descend
into the nasal cavity through the
slit by the side of the crista galli,
and, running along the groove
on the inner surface of the nasal
bone, supply branches to
the lateral wall and septum of
the nose, and a terminal branch
which appears on the dorsum of
the nose between the nasal
bone and the lateral cartilage

29. Frontal sinus
 Frontal recess
 Bounded anteriorly – agger
nasi cell.
 Posteriorly – bulla
ethmoidalis.
 Laterally – lamina
papyracea.
 Medially – middle
turbinate.
 Superiorly – opens via
frontal ostium into frontal
sinus.

30. Posterior ethmoids
 Located posterior to
ground lamellae
 Bigger in size as
compaired to anterior
group
 Variant-onodi cell

31. comparison

32. Posterior ethmoidal artery

33. Superior tubinate and meatus.
 Projection from medial surface of ethmoidal
infundibulum.
 Superior to middle turbinate.
 Superior meatus – below superior turbinate.
 Posterior ethmoidal cells open into it.

34. Olfactory epithelium
 Olfactory area is confined to the following narrow
zones of the nasal cavity:
1. Upper 1/3 of the lining mucosa of the nasal septum
2. Corresponding area of the medial aspect of
superior turbinate
3. Corresponding area of the narrow roof of the
nasal cavity
This portion of mucosa can be readily identified from
the rest of the nasal mucosa by its unique yellowish
color.

35. Sphenopalatine artery

36. Sphenopalatine artery
 sphenopalatine artery (nasopalatine artery)
commonly known as the artery of epistaxis
 branch of the maxillary artery which passes through
the sphenopalatine foramen into the cavity of the nose
 the sphenopalatine artery ends on the nasal septum as
the posterior septal branches. Here it
will anastomose with the branches of the greater
palatine artery.

37. SPHENOID SINUS
 Ostium lies high on its anterior wall close to its roof.
 Drain into sphenoethmoidal recess.
 Lies 1- 1.5 cm above the roof of posterior choana.
 10 % posterior ethmoidal cell extend posterolaterally
over sphenoid sinus – Onodi cell.

38. Sphenoid sinus

39. Types of sphenoid sinus
pneumatization
 Conchal type(3%): In this type the area below the
sella is a solid block of bone without an air cavity. This
type is common in children under the age of 12
because pneumatization begins only after the age of 12.
 Presellar type(11%): In this type the air cavity does
not penetrate beyond the coronal plane defined by the
anterior sellar wall
 Sellar type(85%): In this type the air cavity extends
into the body of the sphenoid below the sella and may
extend as far posteriorly as the clivus.

41. Approaches
 medial to middle turbinate
 Ostium is visualized and anterior wall of sphenoid is
punched downward to open sphenoid sinus.
 intermediate route.

42. MEDIAL APPROACH

43. ONODI CELL
Onodi cells
The
sphenoethmoidal air
cell is generally
defined as the
posterior
most ethmoidal air
cell, that extends
posteriorly to lie
superolateral to
the sphenoid
sinus and thus in
close proximity to
the optic
nerve and internal
carotid artery

44. ONODI CELL
It often extends into the
anterior clinoid process;
importantly aeration of the
anterior clinoid process does
not imply presence of an
Onodi cell, as frequently such
aeration is due to rescesses of
the sphenoid sinus 9.

45. Sphenoid septa
 Never midline
 (optic 7%, ICA 40%)

47. Endoscopic Anatomy of sphenoid
sinus

48. Relationship
 superiorly: cavernous sinus, sella turcica and its
contents
 inferiorly: nasal cavities
 anteriorly: nasal cavities
 posteriorly: contents of the middle cranial fossa,
 laterally: cavernous sinus, cranial cavity

49. Various patterns of internal carotid
in sphenoid sinus

50. Paranasal sinuses
 Air containing cavities in certain bones of skull.
 Clinically divided into two groups:-
anterior group – maxillar sinus, frontal sinus
and anterior ethmoidal sinus.
posterior group – posterior ethmoidal sinuses
and sphenoid sinus.

51. Anterior skull base
 Floor :- * orbital roof
*fovea ethmoidalis
* planum sphenoidale
* cribriform plate.

54. Posterior wall of maxillary sinus

55. Pterygopalatine fossa
 anterior: superomedial part of
the infratemporal
surface of maxilla
 posterior: root of the pterygoid
process and adjoining anterior
surface of the greater
wing of sphenoid bone
 medial: perpendicular plate of
the palatine bone and its orbital
and sphenoidal processes
 lateral: pterygomaxillary fissure
 inferior: part of the floor is
formed by the pyramidal
process of the palatine bone.

56. THANK YOU