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ENDOSCOPIC ANATOMY OF NOSE, PNS AND ANTERIOR BASE OF SKULL.

Endoscopic

Brief Gross anatomy Endoscopic evolution and historical

backgroundEndoscopic anatomySurgical anatomy

NOSE

Development nose – 4th to 8th week IUL.

Nose

External nose

Internal nose

EXTERNAL NOSE

EXTERNAL MUSCULATURE OF NOSE

OSTEOCARTILAGENOUS FRAMEWORK

INTERNAL NOSE

Vestibule

Nasal cavity proper – •Roof•Floor•Medial wall/ nasal septum•Lateral wall

NASAL SEPTUM

LATERAL WALL

Irregular owing to the presence of three shelf like bony projections.

Three parts - vestibule

atrium

meatuses

LATERAL NASAL WALL

Skeleton of lateral nasal wall

Inferior turbinate

Independent bone.

Straight course

Inferior margin overhangs inferior meatus

INFERIOR TURBINATE

INFERIOR MEATUS

Middle turbinate

Projection from medial surface of ethmoidal infundibulum.

Divided into three parts depending upon – attachment and orientation in 3D space.

Attachments

Anatomical variations

Ballooned up – concha bullosa ( pneumatized from frontal recess, agger nasi cell,

anterior ethmoidal cells or middle meatus).Superior meatus pneumatize vertical lamella –

interlamellar cell of Gurnwald.Paradoxically bent turbinate.Tubinate sinus.

ANATOMICAL VARIATIONS

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

Middle meatus

Ethmoidal bullaWell 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.

Frontal recess

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

sinus. Sagittal section the frontal infundibulum, frontal

ostium, frontal recess – HOUR GLASS CONFIGURATION.

Endoscopically – frontal sinus lies more anterior to the recess.

FRONTAL SINUS

Anatomic variation of uncinate process

Extend upto skull baseAttach to lamina papyracea.Attached to insertion of middle turbinate.Lie free in middle meatus.May be pneumatized.

ANATOMIC VARIATION OF UNCINATE

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.

Sphenoid sinus

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.

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.

Anterior skull baseFloor :- * orbital roof *fovea ethmoidalis * planum sphenoidale * cribriform plate.Intacranial site – frontal lobe and cribriform plate.Anteriorly – frontal crest & posterior wall of frontal sinus.Posteriorly – lesser wing of sphenoid bone.Medially – cribriform plateLaterally – frontal lobe.Superiorly – frontal lobe , olfactory bulb and tract.Inferiorly – orbital plate of frontal bone with medial portion

formed by ethmoid sinus.Crista galli defines the midline.

ANTERIOR SKULL BASE

ENDOSCOPIC EVOLUTION

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Endo’ – within ; ‘skopeein’– to seeOptical device with lightingUsed to look inside a body cavity, organ

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1806 Frankfurt made a "Lichtleiter" (light conductor) illuminated by a candle1853 Desormeaux added burning gas flame

to it - “father of endoscopy”modified by Cruise and Andrews light source and mirror attached to the instrument.

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Bruntons otoscope Wales endoscope

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1945 – Karl Storz est his company1951-1965 Harold Hopkins, fundamental

improvements madeSolid glass rods with lenses in between,

providing excellent resolution with good contrast, a large visual field and perfect fidelity of colour

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Diagnostic nasal endoscopyA careful and methodical diagnostic

endoscopy is the key.

Equipment

Procedure

Normal endoscopic findings

Anatomical variations

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Equipment

Light sourceCableEndoscope [0 - 30

degree] , [wide angle] , [2.7 - 4 mm]

Suction tubes [straight - curved]

Forceps [forward - upward]

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.

1ST PASS

2nd passScope 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 plexu.The septal branch of sphenopalatine artery runs

across anterior wall of sphenoid.

2ND PASS

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 processBulge of bulla seen behind uncinate process.Groove btw these two – hiatus semilunarisPalpated with ballpoint goes into infundibulum.

3RD PASS

Uncinate process is removed to expose infundibulum.

Widened anteroinferiorly to see inside of meatus.

Accessory ostia.

Frontal sinus

Upper border of the attachement of uncinate process is removed to expose frontal sinus.

Bulla perforated & removed in lateral direction upto lamina papyracea and in superior direction upto skull base.

Posterior wall is removed.Anterior ethmoidal artery seen.

SPHENOID SINUSGround lamella visualized.

Perforated inferomedially to enter posterior ethmoidal cells.

Removed to expose lamina papyracea laterally, base skull superiorly and superior turbinate medially.

Posterior ethmoidal artery seen.Maxillary ridge.Sphenoid opened inferomedially.Lateral wall – optic nerve and internal carotid artery.

dia

Sphenoid sinus can be approached medial to middle turbinate

Ostium is visualized and anterior wall of sphenoid is punched downward to open sphenoid sinus.

Can be approached by intermediate route.

MEDIAL APPROACH

Anterior skull base

Base skull slope downwards from anterior to posterior direction at an angle of 15.

Olfactory nerves seen.‘frontal sinus.Pituitary gland.Optic nerve Sphenoid sinus.

ANTERIOR SKULL BASE