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Paranasal Sinus Disease: Acute & Chronic, Treatment, and Complications

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1. ANATOMY & OVERVIEW

• Each sinus drains into the nasal cavity:
  • Maxillary, frontal, and anterior ethmoid → middle meatus (via the ostiomeatal complex)
  • Posterior ethmoid → superior meatus
  • Sphenoid → sphenoethmoid recess
• The proximity to the orbit (especially the lamina papyracea of the ethmoid) and the anterior cranial fossa (frontal and ethmoid roofs) explains why spread of infection to these structures is the most feared complication.

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2. ACUTE RHINOSINUSITIS (ARS)

2A. Definition & Classification

2B. Epidemiology

• Adults suffer 2–5 viral URIs/year; school-age children 7–10/year
• Only 0.5–2% of viral rhinosinusitis episodes progress to ABRS
• ~60% of viral URIs show radiologic evidence of maxillary/ethmoid opacification on CT — imaging alone cannot distinguish viral from bacterial disease

2C. Pathophysiology

1. Virally mediated mucosal inflammation → ciliary dysfunction
2. Mucosal edema → obstruction of sinus ostia
3. Mucus stasis → reduced oxygen tension → bacterial superinfection
4. Key anatomic site of obstruction: the ostiomeatal complex (OMC)

2D. Microbiology of ABRS

2E. Clinical Features of ABRS

• Purulent (cloudy/colored) nasal discharge — anterior or posterior
• Nasal obstruction/congestion
• Facial pain/pressure/fullness — may involve periorbital region
• Headache (localized or diffuse)
• "Double worsening" (initial improvement → relapse)
• Periorbital edema (suggests extra-sinus spread)
• Fever, malaise, anosmia

2F. Diagnosis

• Clinical diagnosis: ≥ 10 days of symptoms without improvement, or double worsening
• Anterior rhinoscopy: purulent discharge in middle meatus
• CT sinuses: preferred imaging if complications suspected (NOT for routine uncomplicated ABRS)
• MRI: reserved for intracranial complications, tumors, invasive fungal sinusitis

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3. CHRONIC RHINOSINUSITIS (CRS)

3A. Definition

1. Mucopurulent drainage (anterior or posterior)
2. Nasal obstruction/congestion
3. Facial pain/pressure/fullness
4. Decreased sense of smell

• Purulent mucus or edema in middle meatus/ethmoid region on nasal endoscopy, OR
• Nasal polyps, OR
• CT imaging showing sinus inflammation

3B. Subtypes

3C. Microbiology of CRS

• Different from ABRS; polymicrobial
• Includes S. aureus, coagulase-negative staphylococci, Pseudomonas aeruginosa, anaerobes, and bacterial biofilms
• Biofilm formation is a key factor in CRS persistence and antibiotic resistance

3D. Pathophysiology of CRS

• Systemic immune dysfunction
• Staphylococcal superantigens → polyclonal IgE production
• Pathologic bacterial biofilms → antibiotic recalcitrance
• Aberrant immune response to fungi → eosinophilic inflammation
• Microbial dysbiosis (imbalance of resident nasal microbiome)
• Mucociliary dysfunction (primary or acquired)
• Anatomic obstruction (deviated septum, concha bullosa, Haller cells)

3E. Symptoms of CRS

• Persistent nasal congestion and purulent discharge (> 12 weeks)
• Hyposmia or anosmia (more characteristic of CRS than acute disease)
• Facial pressure/fullness (less severe than ABRS)
• Post-nasal drip, chronic cough
• Nasal polyps visible on endoscopy

3F. Diagnosis of CRS

• Nasal endoscopy: polyps, mucopurulent discharge in middle meatus
• CT sinuses (Lund-Mackay scoring): opacification, mucosal thickening, ostiomeatal complex obstruction — required before surgical planning
• Allergy testing, immunology workup for recalcitrant cases
• Tissue eosinophil count on biopsy

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4. CONSERVATIVE (MEDICAL) TREATMENT

4A. Acute Bacterial Rhinosinusitis

1. Watchful waiting vs. antibiotics — shared decision-making approach is recommended for uncomplicated ABRS
2. First-line antibiotic: Amoxicillin ± clavulanate (oral)
3. Penicillin allergy alternatives: Doxycycline or respiratory fluoroquinolone (levofloxacin, moxifloxacin); TMP-SMX is also an option
4. Nasal saline irrigation — promotes mucociliary clearance
5. Intranasal corticosteroids — reduce mucosal edema, aid ostial drainage
6. Decongestants (short-term topical: oxymetazoline ≤ 3 days; systemic: pseudoephedrine) — reduce congestion
7. Analgesics (NSAIDs, paracetamol) — for pain
8. Patients with suspected complications → immediate antibiotics + urgent ENT referral + IV therapy
9. Duration: 5–7 days for uncomplicated ABRS

4B. Chronic Rhinosinusitis

1. Intranasal corticosteroids (INCS) — cornerstone of CRS medical therapy (fluticasone, mometasone, budesonide); reduces polyp size and mucosal edema
2. Saline nasal irrigation (hypertonic or isotonic) — flushes mucus, reduces microbial load, improves mucociliary clearance
3. Oral corticosteroids — short "rescue" courses for CRSwNP; significant polyp reduction
4. Antibiotics:
   • Short courses for acute exacerbations
   • Long-term low-dose macrolides (e.g., azithromycin, roxithromycin 3 months) — anti-inflammatory and immunomodulatory properties; particularly beneficial in CRS without polyps
5. Antifungal therapy — only for proven invasive fungal sinusitis; no routine use in non-invasive CRS
6. Biologics (newer/refractory CRSwNP):
   • Dupilumab (anti-IL-4Rα) — FDA approved for CRSwNP
   • Mepolizumab (anti-IL-5), benralizumab (anti-IL-5Rα), omalizumab (anti-IgE)
7. Leukotriene receptor antagonists (montelukast) — adjunct in aspirin-sensitive patients
8. Allergy management — allergen avoidance, immunotherapy if allergic sensitization present
9. Management of comorbidities — asthma, GERD, immunodeficiency

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5. SURGICAL TREATMENT

5A. Indications for Surgery

• Failure of adequate medical therapy (typically ≥ 12 weeks)
• Recurrent ABRS with anatomic obstruction
• Complications (orbital, intracranial)
• Mucocele/pyocele
• Suspected neoplasm
• Invasive fungal sinusitis
• Polyp-related obstructive disease refractory to steroids

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5B. MAXILLOTOMY (Caldwell-Luc Operation)

1. Anesthesia: Block the infraorbital nerve, sphenopalatine ganglion, and posterior superior dental nerve
   • Sphenopalatine ganglion blocked via the greater palatine foramen with curved needle
   • Topical cocaine pledgets placed intranasally against the sphenopalatine ganglion
   • Local infiltration of canine fossa mucosa for hemostasis
2. Incision: Horizontal sublabial incision in the canine fossa (above the upper gumline)
3. Bone opening: Anterior wall of the maxillary sinus is perforated and enlarged using a drill or osteotome
4. A nasal antrostomy (inferior meatal window) is made for drainage
5. Removal of diseased mucosa, polyps, inspissated secretions, mycetoma
6. Closure of the sublabial incision
7. The natural ostium is left intact or widened endoscopically

• Chronic maxillary sinusitis refractory to endoscopic approaches
• Maxillary sinus mycetoma
• Dental-related maxillary sinusitis (odontogenic)
• Access for tumor removal or antrochoanal polyp
• Recurrent or complicated maxillary sinusitis

• Infraorbital nerve injury → cheek/upper teeth numbness
• Oroantral fistula
• Damage to dental roots
• Recurrent disease (retained mucosa)

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5C. FRONTOTOMY (Frontal Sinus Surgery)

Open/External Approaches (Historical):

• Incision at the medial canthal region
• Ethmoidectomy + frontal sinus drainage via a nasofrontal duct
• Largely replaced by FESS

• Indications: Recalcitrant frontal sinus disease after failed ESS, mucocele, osteomyelitis
• Bicoronal incision across the vertex of the scalp
• Inferiorly based bone flap hinged on pericranium
• Complete eradication of frontal sinus mucosa (critical — retained mucosa causes mucocele)
• Cavity obliterated with abdominal fat, hydroxyapatite, or left open
• Gold standard for obliteration procedures

• Small external incision in medial eyebrow
• Indicated for: complicated acute/chronic frontal sinusitis, frontal osteomyelitis, far lateral sinus disease, difficult-to-access supra-agger cells
• Can be combined with endoscopic approach

Endoscopic Frontotomy — Draf Classification:

• Grade 0: Balloon dilation only (no tissue removal)
• Grades 1–3: Below the frontal ostium, progressive removal of obstructing cells
• Grades 4–6: Require bone removal with ostium enlargement; Grade 6 = Draf III equivalent

• Height and slope of the skull base
• Anterior ethmoid artery position relative to skull base
• Lamina papyracea shape and integrity
• Agger nasi cells, suprabullar cells, frontal cells (types I–IV)
• Frontal recess diameter

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5D. FUNCTIONAL ENDOSCOPIC SINUS SURGERY (FESS)

1. Remove uncinate process → exposes ethmoidal infundibulum
2. Remove ethmoid bulla → exposes frontal sinus outflow tract and ethmoid roof
3. Resect remaining anterior ethmoid cells
4. Remove basal lamella of middle turbinate → posterior ethmoidectomy
5. Sphenoidotomy (identify and enlarge natural sphenoid ostium)
6. Middle meatal antrostomy (30° endoscope) for maxillary sinus drainage

1. Remove low posterior ethmoid cells → identify sphenoid face
2. Sphenoidotomy → identifies skull base
3. Dissect ethmoid partitions anterior along ethmoid roof

• Decongestion with oxymetazoline/topical epinephrine on pledgets
• Endoscopic injection of 1% xylocaine + 1:100,000 epinephrine
• Sphenopalatine block for posterior work
• Pre-operative review of CT imaging for anatomic variants

• CSF leak (cribriform plate/skull base injury)
• Orbital injury (medial wall/lamina papyracea)
• Anterior ethmoid artery injury → orbital hematoma
• Optic nerve injury
• Bleeding (anterior/posterior ethmoid arteries)
• Anosmia
• Synechiae (adhesions)

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6. RHINOGENIC ORBITAL COMPLICATIONS

Chandler Classification (5 Stages):

Pathogenesis of Orbital Spread:

• Direct extension through the thin lamina papyracea
• Spread via valveless diploic veins connecting sinus mucosa to orbital contents
• Periorbital/preseptal cellulitis → breaks through orbital septum → postseptal spread

Management of Orbital Complications:

1. Chandler I (Preseptal cellulitis):
   • Oral or IV antibiotics (broad-spectrum)
   • Close monitoring; if no improvement → escalate
2. Chandler II (Orbital cellulitis):
   • IV broad-spectrum antibiotics (coverage for S. pneumoniae, H. influenzae, S. aureus, anaerobes)
   • Nasal decongestants, saline irrigation, nasal/oral steroids
   • Close ophthalmologic monitoring
   • CT scan to rule out abscess
3. Chandler III/IV (Subperiosteal/Orbital abscess):
   • IV antibiotics
   • Surgical drainage — indicated if:
     • Decreased visual acuity
     • Afferent pupillary defect
     • Failure to improve after 48 hours of IV antibiotics
     • Large or lateral abscess
   • Small medial subperiosteal abscess in a child with normal vision: may trial 48h medical therapy
   • Drainage options: FESS (endoscopic medial drainage), or external orbitotomy
4. Chandler V (Cavernous sinus thrombosis):
   • All involved sinuses must be drained (including sphenoid sinus)
   • High-dose IV antibiotics (MRSA coverage: vancomycin)
   • Anticoagulation (controversial; no consensus)
   • Neurosurgical and ophthalmology consultation

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7. RHINOGENIC INTRACRANIAL COMPLICATIONS

• Direct extension (osteomyelitis of frontal/ethmoid bone with penetration)
• Spread via diploic/emissary veins (valveless, allowing retrograde flow)
• More common in acute than chronic sinusitis; more common in children and adolescents
• Streptococcus anginosus group (formerly S. milleri) is the hallmark organism for suppurative complications

Types of Intracranial Complications:

Management Principles for Intracranial Complications:

1. Immediate multidisciplinary consultation: Neurosurgery + ENT + Infectious Disease + Ophthalmology
2. CT ± MRI of sinuses and brain (with contrast)
3. Blood cultures in all patients with intracranial complications
4. Lumbar puncture — for meningitis (only after CT to exclude raised ICP)
5. High-dose IV antibiotics:
   • Cover S. pneumoniae, S. anginosus group, anaerobes, S. aureus (including MRSA)
   • Regimen: Vancomycin + Ceftriaxone ± Metronidazole
6. Surgical drainage of sinuses (FESS or open): removes source of infection, permits cultures
7. Neurosurgical drainage of intracranial collections (bur hole or craniotomy)
8. Anticonvulsants for seizures
9. Recovery is variable: depends on age, severity, speed of treatment

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8. SPECIAL SCENARIOS

Invasive Fungal Sinusitis

• Life-threatening; mortality approaches 50% even with treatment
• Pathogens: Aspergillus (septate hyphae, 45° branching) and Mucor/Rhizopus (non-septate, irregular branching)
• Risk factors: hematologic malignancies, bone marrow transplant, poorly controlled diabetes, neutropenia
• CT: bony erosion (late finding); MRI: loss of contrast enhancement in devitalized/necrotic mucosa (better for extent)
• Diagnosis: frozen section biopsy showing angioinvasion
• Treatment: Urgent surgical debridement + systemic antifungals (amphotericin B for mucormycosis; voriconazole for Aspergillus) + reversal of immunocompromise

Sphenoid Sinusitis

• Potentially lethal due to proximity to cavernous sinus, optic nerve, internal carotid artery
• Presents with deep retro-orbital or vertex headache
• Requires urgent drainage if suspected

Odontogenic Sinusitis

• Accounts for 10–40% of maxillary sinusitis cases
• Upper molar roots project into the maxillary sinus floor
• Dental infection or procedures (implants, extractions) → bacterial inoculation of sinus
• Often polymicrobial with anaerobes
• Requires both dental treatment and sinus surgery (Caldwell-Luc or FESS)

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Summary Table

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