Presentation on theme: "Diseases of the paranasal sinuses Ehab ZAYYAN, MD, PhD"— Presentation transcript:
1 Diseases of the paranasal sinuses Ehab ZAYYAN, MD, PhD
2 Embryology Ethmoid sinuses: 0- 12 y Frontal sinus: 6- 20 y Maxillary sinus:yyRadiology: 1 yearSphenoid sinus: 3- 20
3 Anatomy of the sinuses Maxillary sinus (Antrum of Highmore) The largest paranasal sinus10-20 cc in volumeFloor: alveolar processRoof: orbital floorMedial wall: bony+ membranous (ant and post fontanelles)Ostium opens in the middle meatus, in the lower paret of the ethmoid infundibulum.Accessory ostia may be found in the ant or post fontanelle in 25% of people (clinical importance!!)
4 Anatomy Ethmoid Sinuses lamina cribrosa (cribriform plate) Crista galliPerpindicular laminaLamina paperaceaAir cells: (average: 9) in each side
5 Relations of the ethmoids: Anterior: orbit and nasolacrimal ductPosterior: sfenoid sinus, orbital apex, optic nerveLateral: orbitSuperior: skull base
6 Anatomy Anterior ethmoid cells drain into the middle meatus Ground lamella (attachment of the middle turbinate to the lat nasal wall)Posterior ethmoid cells drain into the upper meatus
7 Anatomy Uncinate process Hiatus semilunaris: curved space between the uncinate and ethmoid bulla. Entrance to the ethmoid infundibulum.Ethmoid infundibulum: the drainage site of the maxillary, frontal, anterior ethmoid cells.Bulla ethmoidalis: the most constant and the largest anterior ethmoid cellGround lamellaPosterior ethmoid cells (eg. Onodi cell)
8 Frontal Sinus Paired asymmetric sinuses Absent unilaterally in 12% and bilaterally in 5%Drainage:Frontal ostium→ Nasofrontal duct →Frontal recess →Ethmoid infundibulum
9 Sphenoid sinus Lies in the center of the head - Above : optic nerve and pituitary gland- Laterally: orbital apex, cavernous sinus, carotid arteries- Posterior: basillar artery, pons- Inferiorly: nasopharynxDrainage: sphenoethmoidal recess into the superior meatus
10 HistologyThe nasal vestibule is lined with stratified squamous epithelium with vibrissae, sweat glands, and sebaceous glands.The sinonasal mucous membrane is pseudostratifed, columnar, ciliated epithelium (respiratory epithelium.Olfactory epithelium.
11 The sinus mucosa compared to nasal mucosa: ThinnerShorter epitheliumBasal membrane is very thinLess goblet cellsVery few seromusinous glands in the submucosaLamina propria is is very thin and firmly adherent to the periostium
12 Physiology The mucous membrane consists of two layers: Gel layer: thick viscous elastic layerSol layer: serous layer between the ciliaDaily mucous secretion: 600 – 1800 ccContains a lot of substances mainly lysozymes and immunoglobulins.
13 Ciliary movements:cilia/ cell8-20 beat/ secondThe movement is towards the natural ostium not towards the gravity.For maximum ciliary activity:Humidity: >85%Temperature: degree CpH: 7- 8
14 Normal ventilationNormal drainageCiliary movements
16 secretions in the sinuses Hypoxia↓Vasodilatation Ciliary dysfunction Mucous gland↓ dysfunction↓ Stasis ↓Transudation Accumulation of thick ← thick fluidsecretions in the sinusesBacterial growth
17 Osteomeatal complexThe most commonly infected structure in the sinusesCan be obstructed and inflammed easily with even minimal edemaCan not be examined by anterior rhinoscopy but with endoscopyCan not be evaluated by conventional radiology but needs CT
18 Obstruction of the osteomeatal complex Anatomic variationsForeign bodyMucociliary dysfunctionAllergyInfectionsLocal inflammation↓Obstruction of the osteomeatal complexSinusitis
19 Osteomeatal complex obstruction, ↓ Decreased ventilation of the sinuses,Decreased drainage of the sinusespO2 decrease, pCO2 increase, mucous stasisInflammation and viscous mucous, ciliary movement slowingStasis and proteolytic enzymesCiliary damageAnaerobic microrganismsMore damage……
28 1.Initial phase Edema and hyperemia of the sinus mucosa Transudate accumulation and serous fluidReversibleIf the ostium is not obstructed it resolves spontaneously
29 2. Ostium obstruction phase Sinus drainage and ventilation decreasesThe secretion becomes thicker and more viscousVentilation decreases more, pO2 pressure ↓, CO2 ↑A good media for anaerobes develop
30 3. Bacterial phase Rapid bacterial growth Anaerobic bacterial growth Local inflammationViscosity increasesCiliary activity decreasesIf not treated chronic changes start
31 4.Chronic phase Immune activities stop Irreversible changes occur Mucosal destructionCiliary activity stopsThe 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….
32 FESSThe target of Functional Endoscopic Sinus surgery (FESS) is to remove the pathology of the osteomeatal complex to maintain normal ventilation and drainage to the sinuses.Anatomic variations (septal deviation, concha bullosa, uncinate variations, ….)Foreign bodyNasal polypsChronic sinusitis
34 Acute sinusitis Preceding viral infection is the most common cause Bacterial etiology: S. pneumonia, H. influenza, M. catarrhalis, S. aureus, S. pyogensAnaerobic (more common in chronic)Nosocomial (gram negative bacteria)
36 Examination Nasal congestion and discharge Post-nasal discharge Tenderness over the sinusesTransillumination
37 RadiologyPlain x- rays: opacity/ air- fluid level in the maxillary, sphenoid, frontalCT: for the ethmoid (not indicated for acute cases)
38 Cultures From nasal discharge is unreliable From the middle meatus are 70% correlatedSinus puncture is the best.Not routinely indicated.
39 The diagnosis of acute sinusitis is mainly by history and physical examination.
40 Treatment Antibiotics: (10- 14 days) Amoxicillin Trimethoprim- sulfamethaxazoleAmoxicillin- clavulonic acidCefuroxime and second generation cefalosporinsClarithromycin
41 2. Oral decongestants3. Local decongestants (3- 5 days)4. Mucolytics5. Antihistaminics6. Nasal saline irrigation7. analgesics/ anti-inflammatorySinus puncture: in very painful conditions and in non- responsive cases.Frontal sinusitis: close follow up and iv therapy if needed.
42 Pediatric sinusitis Can be confused with URTI Rhinosinusitis URTI symptoms > 5- 7 days. More severe symptoms and high fever.Recurrent sinusitis: 3 or more attacks in 6 months or 4 or more in one yearChronic sinusitis: persistence of symptoms more than 3 months
43 Underlying factors for recurrent/chronic sinusitis in periatric population: Allergy, passive cigarette smoking, kindergarten, adenoid vegetation, immunodefeciency, immotile cilia syndrome, cystic fibrosis.Therapy: treat the underlying factors, medical therapy, surgical therapy.
44 Chronic sinusitis Persistent signs and symptoms beyond 8 to 12 weeks. Mostly headache, chronic nasal obstruction, postnasal discharge.Microbiology: common m.o. + anaerobesDiagnosis: paranasal sinus CTTreatment: 4 weeks second line antibiotics+ coverage for anaerobes (Metronidasole, clindamycin)Usually needs surgical intervention
45 Acute fulminant (invasive)fungal sinusitis (Mucormycosis) Rapidly progressive disease caused by family of Mucoracea: Rhizopus, Mucor, Absida. Less commonly due to Aspergillus species.Occurs only in immunocopromized patients.
46 The fungi invade the blood vessel walls producing thrombosis, ischemic infarction, and necrosis and allowing spread of the disease.The necrotic tissue provides ideal medium for fungal growth.Patients are acutly ill, fever, lethargy, facial pain.Examination: dark, necrotic turbinates and septum. Black facial necrosis and perforations of the septum and the palate.Can invade the brain, the orbit and other vital structures.
47 Diagnosis: staining and cultures, CT, MRI. Treatment:Control of the underlying disease (DM…)Radical debridement of all necrotic tissue.IV amphotericin B for several months.
48 Chronic indolent fungal sinusitis Endemic in hot dry areas like Sudan and IndiaMainly by AspergillusImmunocompetent non-atopic patientsThe same symptoms of chronic sinusitisSlowly progressive invasive disease causing bone necrosis and chronic granulomatous infiltrate.Diagnosis: demonistration of tissue invasionTreatment: surgical removal + antifungal agents
49 Mycetoma (fungus ball) Chronic non-invasive fungal infection. Usually affects a single maxillary sinus.Immunocompetent nonatopic hosts.Aspergilloma (caused by aspergillus)Treatment: surgical removal.
50 Allergic fungal sinusitis 5 to 10% of chronic sinusitis casesAtopic young adults/ adolescents with history of recurrent sinusitis and surgeries.Nasal polyposis and positive skin tests are commonRubbery green/ brown mucoid discharge and nasal polyps.Staining of mucous: extramucosal hyphae, eosinophils, Charcot- Leyden crystals (Allergic mucin)IgE can be elevated, positive fungal skin test
52 CT: unilateral involvement of multiple sinuses, bony erosions, metalic density of the mucous Treatment:AntibioticsSteroidsAntifungalsFESS
53 Sinobronchial syndrome 25% of patients with nasal polyps develop asthma and vice versa.Bronchial asthma and sinusitis are manifestations of the same underlying respiratory system disorder.Bronchial smooth muscles↔ nasal mucosa venous sinusoidsCauses of asthma in chronic sinusitisNasal obstructionPostnasal dripReflex bronchospasm (trigeminal vagal reflex)
55 Complications of sinusitis 1. local complications MucocelePrimary mucocele (mucous retention cyst): due to obstruction of the minor salivary glands and usually seen in the maxillary sinus. Silent.Secondary mucocele: due to sinus ostia obstruction. Most commonly in the frontal sinus. Slow growth, bony erosions. Expand in the orbit and the cranial cavity.
56 OsteomyelitisMost frequently in the frontal boneErosion through the anterior wall and development of subperiosteal abcess produces forehead swelling called Pott`s puffy tumor.Intracranial extention may happen.Treatment: iv AB + debridment