1. Diseases of the paranasal sinuses Ehab ZAYYAN, MD, PhD

2. Anatomy

3. Paranasal sinuses
Cavities found in the interior of the maxilla, frontal, sphenoid and ethmoid bones.
The function of the sinuses is to act as resonators of the voice and to reduce the weight of the skull.

5. Paranasal sinuses

6. Maxillary sinuses
The maxillary sinus drains into the middle meatus

7. Frontal sinuses Two in number
15 % of humans have a single frontal sinus
5 % of humans has no frontal sinus.
Each frontal sinus opens into the middle meatus

8. Sphenoidal sinuses Two in number
Lie within the body of the sphenoid bone
At the center of the skull
Each sinus opens into the sphenoethmoidal recess → superior meatus

9. Ethmoidal sinuses
Separated from the orbit via a thin plate called the lamina papracea.
Air cells: (average: 9) in each side
Divided into 2 groups:
Anterior group: opens into the middle meatus
Posterior group: opens into the superior meatus

11. Relations of the ethmoids:
Anterior: orbit and nasolacrimal duct
Posterior: sfenoid sinus, orbital apex, optic nerve
Lateral: orbit
Superior: skull base

14. lateral nasal wall Superior, middle and inferior conchae.
The area below each concha is called meatus: superior, middle and inferior meatus

18. Embryology Ethmoid sinuses: 0- 12 y Frontal sinus: 6- 20 y
Maxillary sinus: y y
Sphenoid sinus: 3- 20

20. Histology
The nasal vestibule is lined with stratified squamous epithelium with vibrissae, sweat glands, and sebaceous glands.
The mucous membrane lines the nasal cavity except the vestibule. There are two types of mucous membranes:
1. Olfactory mucosa
2. Respiratory mucosa

21. 1. olfactory mucous membrane: lines the superior surface of the superior concha and the sphenoethmoidal recess. It also lines the corresponding part of the nasal septum

22. Its function is to warm, moisten and clean the inspired air.
2. The respiratory mucous membrane:
Pseudostratified ciliated, columnar epithelial cells, goblet cells, and submucosal glands
Its function is to warm, moisten and clean the inspired air.
Warming: venous plaxus in the submucosa
Moisture: mucous by the glands and goblet cells
Ciliary action….

23. Physiology The mucous membrane consists of two layers:
Gel layer: thick viscous elastic layer
Sol layer: serous layer between the cilia
Daily mucous secretion: 600 – 1800 cc
Contains a lot of substances mainly lysozymes and immunoglobulins.

24. Ciliary movements:
cilia/ cell
8-20 beat/ second
The movement is towards the natural ostium not towards the gravity.
For maximum ciliary activity:
Humidity: >85%
Temperature: degree C
pH: 7- 8

25. The sinus mucosa consists of pseudostratified ciliated, columnar epithelial cells, goblet cells, and submucosal glands that produce a protective mucous blanket.
The mucosal blanket traps bacteria and noxious materials, which are carried by ciliary motion to the ostium and into the nose for elimination.
The orientation of the cilia within a given sinus is specific as secretions are propelled towards the natural sinus ostia and from there to the nasopharynx and oropharynx where they are subsequently cleared by swallowing.
This mucosa is similar to that found in the nose and tracheobronchial tree

26. For normal function
Normal ventilation
Normal drainage
Ciliary movements

27. Examination of the paranasal sinuses
Palpation
Transillumination
Nasal cavity regular and endoscopic examination
Radiologic examination:
- Sinus Water x- ray
- Coronal sinus CT

28. Anterior rhinoscopy

29. Posterior rhinoscopy

33. Frontal sinus

34. Sinonasal imaging Plain sinus radiographs: Sinus opacifications
Air-fluid level
Mass
Fractures

36. Water view Best for maxillary sinuses and orbital rims
Blow-out fractures

37. Computed tomography Excellent views of the sinuses Coronal section
Best for osteomeatal complex and ethmoidal disease

38. MRI Excellent soft tissue definition Neoplastic disease evaluation
Fails to demonstrate bone
Expensive
Claustra- phobia

39. Pathophysiology of sinusitis

40. Osteomeatal complex
The most commonly infected structure in the sinuses
Can be obstructed and inflammed easily with even minimal edema
Can not be examined by anterior rhinoscopy but with endoscopy
Can not be evaluated by conventional radiology but needs CT

41. Osteomeatal complex

42. Factors negatively affecting the mucociliary activity
Dryness of air
Cigarette
Temperature
Hypoxia
Hypercapnia
Hypertonic/ hypotonic fluids
Dehydration
pH changes
Cystic fibrosis
Primary ciliary dyskinesia
Drugs ( phenylphrine, adrenaline, lidocaine, atropine, antihistaminic).
Infections
Anatomic obstruction (septum, turbinate,..)
Foreign body
Nasal polyps

43. secretions in the sinuses
Hypoxia ↓
Vasodilatation Ciliary dysfunction Mucous gland
↓ dysfunction
↓ Stasis ↓
Transudation Accumulation of thick ← thick fluid
secretions in the sinuses
Bacterial growth

44. Obstruction of the osteomeatal complex
Anatomic variations
Foreign body
Mucociliary dysfunction
Allergy
Infections
Local inflammation ↓
Obstruction of the osteomeatal complex
Sinusitis

45. Osteomeatal complex obstruction, ↓ Decreased ventilation of the sinuses, Decreased drainage of the sinuses pO2 decrease, pCO2 increase, mucous stasis Inflammation and viscous mucous, ciliary movement slowing Stasis and proteolytic enzymes Ciliary damage Anaerobic microrganisms More damage……

46. Pathophysiological stages of sinusitis
Initial phase
Ostium obstruction phase
Bacterial phase
Chronic phase

47. 1.Initial phase Edema and hyperemia of the sinus mucosa
Transudate accumulation and serous fluid
Reversible
If the ostium is not obstructed it resolves spontaneously

48. 2. Ostium obstruction phase
Sinus drainage and ventilation decreases
The secretion becomes thicker and more viscous
Ventilation decreases more, pO2 pressure ↓, CO2 ↑
A good media for anaerobes develop

49. 3. Bacterial phase Rapid bacterial growth Anaerobic bacterial growth
Local inflammation
Viscosity increases
Ciliary activity decreases
If not treated chronic changes start

50. 4.Chronic phase Immune activities stop Irreversible changes occur
Mucosal destruction
Ciliary activity stops
The irreversibla changes usually affect some of the mucosa, so if surgery (FESS) is performed, the rest of the mucosa can be saved and start functioning….