Principles of Functional Endoscopic Sinus Surgery

1. Principles of Functional Endoscopic Sinus Surgery ShahinBastaninejad, MD Assistant Prof. of ORL-HNS TUMS Amir’Alam Hospital

2. Outline • Definition • Anatomy • Patient evaluation • FESS Concepts of Surgery

3. Definition

4. Functional Endoscopic Sinus Surgery • Replaced old practice of obliterating sinuses and removing mucosa. Concept of irreversibly diseased mucosa refuted. • Functional aspect refers to: • Preserving normal structures • Removing only obstruction • Preserving mucosa • Attempt to restore function

5. Anatomy

6. Ethmoid anatomy is complex: Labyrinth Lamellae 1st - Uncinate 2nd - Ethmoid bulla 3rd - Basal lamella of middle turbinate 4th - Superior turbinate Ethmoid anatomy

7. Drainage • Frontal, anterior ethmoid & maxillary – OMC • Posterior Ethmoids – Superior meatus • Sphenoid sinus – Sphenoid-ethmoidal recess

8. Middle Turbinate • Three components • First – Anterior, oriented in a sagittal plane and attached to skull base • Second – Middle, oriented in a Vertical plane and attached to lamina papyracea (basal lamella and separates ant from post ethmoids) • Third – Posterior, oriented in a horizontal plane and attaches to perpendicular plate of palate (forms roof of middle meatus, anterior to sphenopalatine foramen)

9. Middle Turbinate

10. Ostiomeatal Complex (OMC) • Common drainage for frontal, maxillary and anterior ethmoid sinuses.

11. OMC

12. OMC • Infundibulum – funnel shaped area whereby the maxillary, ant ethmoid and frontal sinuses drains • Uncinate process– Sickle shaped bony ethmoidal structure • Hiatus Semilunaris– Half-moon shape opening of infundibulum

13. Uncinate Process • Attaches to the following structures: • Inf & far post. – To ethmoid process of inf. Turb

14. Uncinate Process • Ant & far sup. – To lamina papyracea, skull base or mid turb

15. Laterally – Lamina papyracea and fontanelle area

16. Uncinate Process 52%

18. Bulla Ethmoidalis • The greatest anterior ethmoid air cell, attached to lamina papyrcea and usually open into lateral sinus

20. Sinus Lateralis = Suprabullar recess and retrobullar recess

21. Middle turbinate: Horizontal and vertical basal lamella SBR Sinus Lateralis RBR

22. Sphenoid Ostium • Medial to posterior sup. turbinate • Located between nasal septum and inferior aspect of sup. turbinate • Located at the same level as the roof of the maxillary sinus • Located 4 microdebrider/suction tip breaths above the choanae • Located 7cm from nasal crest at 30°

23. Sphenoid Ostium

24. Sphenoid Sinus • Relationships of important structures: • Optic nerve – superior-lateral • Carotid artery/cav sinus – mid-lateral • Vidian nerve and maxillary nerve – inferior-lateral

25. Square – ant clinoid process, Circles – optic canals, triangle – vidian nerve Asterisk – pneumatization of pterygoid process

26. Sphenoid Classification

27. Presellar Sellar Conchal Post sellar

28. Onodi Cells or Sphenoethmoid cells

29. Optic Canal in Onodi Cells

30. anatomic keyhole in SBS

31. LOCR

32. Cribriform plate Keros classification 1-3mm 3-7mm 7-16mm

33. Keros Classification • Type I • 1-3mm • Type II • 3-7mm • Type III • 7-16mm

34. Fovea and Ethmoidal arteries

35. Lens 70 degree – End of surgery

36. Kuhn Cells Frontal Cells

37. Frontal Recess • Anatomic Boundries: • Ant – unicate process & aggernasi • Post – bulla ethmoidalis and suprabullar lamella • Lateral – lamina papyracea • Medially – hiatus semilunaris or middle turb • Inf – Ethmoidinfundibulum • Sup – Fovea ethmoidalis, supraorbital air cell, anterior ethmoid artery and frontal ostium

38. Draf IIA Draf I

39. Draf III Draf

40. Frontal Sinus – Mucociliary Pattern  Save Mucosal Layer in Lateral part while performing Draf III opertation

41. Patient evaluation

42. Pre-op CT Evaluation • CLOSE Technique • C – Cribriform • L – Lamina Papyracea • O – Orbits, onodi cell, Optic Nerve • S – Sphenoid, Skull Base • E – Ethmoid Arteries

43. C - Cribriform • Assess the Keros type • Look for assymetry

45. L – Lamina Papyracea • Check for dehiscence or pathologic fractures

46. O – Orbit, Optic Nerve, Onodi Cells • Check for dehiscence • Assess for onodi cells (superior-lateral to sphenoid) • Orbital slope

47. S – Sphenoid, Skull base • Assess for Carotid dehiscence and aeration patterns • Conchal, Pre-sellar, & Sellar (thickness of clivus)

48. Skull base • Assess slope of skull base • Assess if roof of sphenoid is level with skull base

49. E – Ethmoid Artery

50. FESS Concepts of surgery