Endoscopic anatomy of nose and PNS

Endoscopic anatomy of nose and PNS

1. 1 ENDOSCOPIC ANATOMY OF NOSE, PNS AND ANTERIOR BASE OF SKULL.

2. Endoscopic Brief Gross anatomy Endoscopic evolution and historical background Endoscopic anatomy Surgical anatomy

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

4. EXTERNAL NOSE

5. EXTERNAL MUSCULATURE OF NOSE

6. OSTEOCARTILAGENOUS FRAMEWORK

7. INTERNAL NOSE Vestibule Nasal cavity proper – Roof Floor Medial wall/ nasal septum Lateral wall

8. NASAL SEPTUM

9. LATERAL WALL Irregular owing to the presence of three shelf like bony projections. Three parts - vestibule atrium meatuses

10. LATERAL NASAL WALL

11. Skeleton of lateral nasal wall

12. Inferior turbinate Independent bone. Straight course Inferior margin overhangs inferior meatus

13. INFERIOR TURBINATE

14. INFERIOR MEATUS

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

16. Attachments

17. 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.

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. Middle meatus

21. 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 .

22. 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 .

23. FRONTAL SINUS

24. Anatomic variation of uncinate process Extend upto skull base Attach to lamina papyracea . Attached to insertion of middle turbinate. Lie free in middle meatus . May be pneumatized .

25. ANATOMIC VARIATION OF UNCINATE

26. 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.

27. Sphenoid sinus

28. 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.

29. 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.

30. Anterior skull base Floor :- * 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 plate Laterally – 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.

31. ANTERIOR SKULL BASE

32. ENDOSCOPIC EVOLUTION 37 Endo’ – within ; ‘skopeein’– to see Optical device with lighting Used to look inside a body cavity, organ

33. 38 1806 Frankfurt made a " Lichtleiter " (light conductor) illuminated by a candle 1853 Desormeaux added burning gas flame to it - “father of endoscopy” modified by Cruise and Andrews light source and mirror attached to the instrument.

34. 39 Bruntons otoscope Wales endoscope

35. 40 1945 – Karl Storz est his company 1951-1965 Harold Hopkins, fundamental improvements made Solid glass rods with lenses in between, providing excellent resolution with good contrast, a large visual field and perfect fidelity of colour

36. 43 Diagnostic nasal endoscopy A careful and methodical diagnostic endoscopy is the key. Equipment Procedure Normal endoscopic findings Anatomical variations

37. 44 Equipment Light source Cable Endoscope [0 - 30 degree] , [wide angle] , [2.7 - 4 mm] Suction tubes [straight - curved] Forceps [forward - upward]

38. 1 st 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.

39. 1 ST PASS

40. 2 nd 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 plexu . The septal branch of sphenopalatine artery runs across anterior wall of sphenoid.

41. 2 ND PASS

42. 3 rd 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 Bulge of bulla seen behind uncinate process. Groove btw these two – hiatus semilunaris Palpated with ballpoint goes into infundibulum .

43. 3 RD PASS

44. Uncinate process is removed to expose infundibulum . Widened anteroinferiorly to see inside of meatus . Accessory ostia .

45. 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.

46. SPHENOID SINUS Ground 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.

47. dia

48. 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.

49. MEDIAL APPROACH

50. 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.

51. ANTERIOR SKULL BASE