Endoscopic Sinus Surgery Flashcards
Discuss the Lund-MacKay score for Chronic Rhinosinusitis
Radiographic staging score for CRS
- Scored out of 24
- Individual sinuses on each side (left and right) are graded
- 0 = non-opacified, 1 = partially opacified, 2 = obstructed
- Ostiomeatal complex is scored 0 or 2 (non-obstructed vs. obstructed)
- Results in a total score of 12 per side, and 24 overall
- ≤2 excellent NPV, ≥5 excellent PPV
Components:
1. Anterior ethmoids (0/1/2)
2. Posterior ethmoids (0/1/2)
3. Frontal sinuses (0/1/2)
4. Sphenoid sinuses (0/1/2)
5. Maxillary sinuses (0/1/2)
6. OMC (0/2)
What are the EPOS2020 criteria for endoscopic sinus surgery?
- LM score of >1 after a minimum of 8 weeks trial of appropriate medical therapy (INCS ± systemic antibiotic)
AND
- SNOT-22 ≥ 20 post medical treatment
What are the relative contraindications to endoscopic sinus surgery? 5
- Absence of OMC abnormality, LM < 2
- Osteomyelitis
- Inaccessible frontal disease
- Stenosed frontal ostia
- Threatened intracranial complication
“OSTIA”
Osteomyelitis
Stenosed frontal ostia
Inaccessible frontal disease
Threatened intracranial complication
Absence of OMC abnormality, LM < 2
What are the goals that are aimed to be achieved for “functional” sinus surgery?
- Creates a sinus cavity that incorporates the natural ostium
- Allows adequate sinus ventilation
- Facilitates mucociliary clearance
- Facilitates instillation of topical therapies
“MINi Van”
Mucociliary clearance
Instillation of topical therapies
Natural ostium
Ventilation
What is the spectrum of functional endoscopic sinus surgery, according to EPOS 2020? 2
- Full FESS: Complete sinus opening including anterior and posterior ethmoidectomy, middle meatal antrostomies (likely large), sphenoidotomy and frontal opening
- Radical FESS: Significant removal of inflamed/dysfunctional mucosa
How do you optimize the operative field in endoscopic sinus surgery? 5
- Positioning - Reverse trendelenburg
- Local anesthetic & vasoconstriction
- TIVA - Total IV anesthetic
- Tranexemic acid
- Hypotensive anesthesia (MAP ~ 65)
What are the different anatomic findings that can be found in a revision FESS (causes of failed FESS)?
- Incomplete anterior ethmoidectomy with mucosal disease - 65%
- Retained agger nasi with frontal disease - 50%
- Retained uncinate, accessory ostium - 50%
- Incomplete posterior ethmoidectomy with mucosal disease - 40%
- Middle meatal stenosis - 40%
- Recurrent polyps - 40%
- Conchal bullosa
“AEIOU Plus Me”
Agger nasi
Ethmoidectomy incomplete (anterior and posterior)
Incomplete middle turbinate - concha bullosa
Ostium accessory
Uncinate retained
Polyps recurrent
Middle meatal stenosis (synechiae)
Where is the targeted location of drilling for caldwell luc procedure?
What are 8 indications and 10 complications of a Caldwell Luc Procedure?
CALDWELL LUC:
- Through canine fossa between root of canine and 1st premolar
Indications:
1. Access for sinonasal tumors of the maxillary sinus
2. Access for the pterygopalatine fossa (e.g. IMAX ligation, vidian neurectomy, biopsy of skull base lesions)
3. Access to the orbital floor
4. Maxillary abscess drainage or foreign body, tumor, mycetoma, multiseptate mucocele, or antrochoanal polyp
5. Chronic maxillary sinusitis not amendable to endoscopic drainage
6. Repair of oroantral fistula
7. Repair of trauma
8. Orbital decompression of Grave’s ophthalmopathy
Complications:
1. Infection
2. Scarring (upper gingivobuccal sulcus)
3. Tethering
4. V2 hypoaesthesia
5. Cheek bruising/swelling
6. Damage to canine tooth root
7. Oroantral fistula
8. Facial pain or numbness of infraorbital nerve distrbution and the branches (anterior superior alveolar nerve)
9. Epiphora
10. Bone thickening
Regarding medial maxillectomy, discuss:
1. What are the structures taken? (5)
2. What are the indications? 1
3. What are the contraindications? 5
4. What are the complications? 9
STRUCTURES TAKEN: “IM LALAlA”
1. Lateral nasal wall.medial maxillary sinus wall (inferior and middle turbinate)
2. Anterior ethmoid sinuses
3. Lamina papyracea
4. Inferior and medial orbital floor
5. Lacrimal bone
INDICATIONS:
1. Benign or low-grade malignant tumors confined to medial maxillary wall and/or antrum and/or ethmoid sinus
CONTRAINDICATIONS:
Extension beyond the limits defined above, such as:
1. Involvement of the palate
2. Involvement of the periorbita/orbit
3. Skull base or intracranial extension
4. Extension to the pterygoid plates
5. Extension to the other walls of the maxillary sinus
COMPLICATIONS:
1. Telecanthus (increased distance between corners of eyelids)
2. Enopthalmos
3. Hypertrophic/keloid scar
4. Epiphora (excess tears or watery eyes) or Dacryocystitis
5. V2 paresthesias or numbness / Facial neuralgia/dysesthesia
6. Mucocele
7. Diplopia (possibly transient) / EOM muscle entrapment
8. Oroantral fistula
9. Nasal collapse
Kevan Page 45
Describe 5 methods to find the sphenoid os in FESS.
What are the anatomic relationships of the sphenoid ostium to the remainder of the nasal cavity?
- From Sphenoethmoidal Recess
- Start in the sphenoethmoidal recess and take down the superior turbinate from an inferomedial to superolateral direction - Below Maxillary Sinus Roof
- Always lower than the level of the maxillary roof - Angle from nasal spine
- 6.2-8cm from the nasal spine (7cm), at an angle of 30-34 degrees (30deg) - 1/2 to 2/3 up anterior wall of sphenoid
- Bolger’s Parallelogram
RECALL: Anatomic relationships of the sphenoid ostium
1. 7cm from the anterior nasal spine (posterior sphenoid wall ~9cm)
2. 30 degree angle from the floor of the nose (most reliable)
3. 1-1.5cm above the upper limit of the choana
4. 1/3 up from the choana to the skull base
5. Adjacent to the posterior border of the nasal septum (2-3mm)
6. Inferomedial to the posterior attachment of the superior turbinate on sphenoid face (Parson’s ridge)
Kevan Page 50
What is Bolger’s Parallelogram? What are its borders? What is the clinical significance?
Parallelogram formed by:
1. Skull base
2. Superior turbinate
3. Basal lamella of superior turbinate
4. Lamina papyracea
- The sphenoid sinus ostium should be in the inferomedial part of the parallelogram
- Area is safety is medial part of the parallelogram (see Kevan Page 51)
Kevan Page 51
Vancouver Pg 409
What are the boundaries of the opticocarotid recess?
SUPERIOR: Optic nerve
INFERIOR: Internal carotid artery (parasellar)
ANTERIOR: CNIII (Oculomotor nerve)
What are the pneumatization patterns of the sphenoid sinus?
4 pneumatization patterns:
1. Conchal (5%): Does not abut sella
2. Pre-sellar (15%): In front of sella
3. Sellar (80%): In front of and below sella
4. Post-sellar: In front of, below, and behind sella
Kevan Page 52
What are the distances of the anterior ethmoid artery, posterior ethmoid artery, and optic nerve from the lacrimal crest?
24-12-6 rule
- Anterior ethmoid artery is 24mm back from lacrimal crest
- Posterior ethmoid artery is 12mm back from AEA
- Optic nerve is 6mm back from PEA
Hence, distances are:
- AEA = 24mm
- PEA = 24+12mm = 36mm
- ON = 24+12+6 = 42mm
Describe the Draf Classification of Frontal Sinusotomy.
What is the indication for Draf I vs Draf III?
Draf 1: Anterior ethmoidectomy + Confirmation of FSDP
- Remove obstructing disease inferior to frontal ostium without altering ostium (e.g. anterosuperior ethmoid cells)
- Indicated in minor pathology, patient without adverse prognostic risk factors (ASA, intolerance, asthma, NP, etc.)
Draf 2a: Remove floor of frontal sinus between middle turbinate and lamina papyracea (create an opening)
- Extended drainage with ethmoidectomy and resection of the floor of the frontal sinus between the lamina papyracea and the middle turbinate
Draf 2b: Remove floor of frontal sinus between septum and lamina papyracea
- Anterior to the ventral margin of the olfactory fossa
Draf 3 (aka. Modified Lothrop): Bilateral type 2b + removal of superior nasal septum and intersinus septem of the frontal sinus to create a common cavity
- Results in an opening from Lamina Papyracea to contralateral Lamina
- Diameter should be ~1.5cm
- AP diameter of the frontal sinus should be ≥8mm to undergo a Draf III, otherwise consider an osteoplastic flap
- Indicated if chronic failure despite the above
Kevan page 54
What is the international classification of the extent of endoscopic frontal sinus surgery in FESS?
- Grade 0: Balloon sinus dilatation
- No tissue removal - Grade 1: Clearance of cells in the frontal recess (that do not directly obstruct the ostium) without surgery within the frontal ostium
- SACs and SBCs that do not encroach on or obstruct the frontal ostium - Grade 2: Clearance of cells directly obstructing the ostium
- SACs or SBCs that encroach on and obstruct the FSDP
- These cells occupy the space directly below the ostium and narrow the drainage pathway
- Do not include SAFCs, SBFCs, or FSCs - Grade 3: Clearance of cell pneumatizing through the frontal ostium into the frontal sinus without enlargement of the frontal ostium
- SAFCs, SBFCs, and FSCs
- Bone from the beak - Grade 4: Clearance of a cell pneumatizing through the frontal ostium into the frontal sinus with enlargement of the frontal ostium
- Large SAFCs, large SBFCs, or FSCs with a narrow frontal ostium (narrow AP diameter) - Grade 5: Enlargement of the frontal ostium from the lamina papyracea to the nasal septum (unilateral frontal drill out)
- Large SAFCs, large SBFCs, or FSCs with a narrow frontal ostium (narrow AP diameter) - Grade 6: Frontal drill out/modified lothrop or Draf 3
- Performed after failure of previous standard sinus surgery where the frontal ostium is stenosed with scar tissue or new bone formation
- Maximum possible AP and lateral diameter
What are the 3 primary goals of FESS?
- Restore normal mucociliary clearance and flow
- Remove diseased/obstructing tissue
- Leave healthy tissue and sinuses alone
Describe your pre-op CT assessment in preparation for FESS
“Fucking CLOSED Man Pffft”
F: Frontal sinus/recess and agger nasi
C: Cribriform plate (Keros Classification)
L: Lamina papyracea (and uncinate relationship)
O: Onodi cells
S: Sphenoid sinus (optic nerve, ICA)
E: Ethmoid (Anterior ethmoid artery)
- Kennedy’s nipple sign
- Location of AEA: is there a supraorbital cell? Is it at risk of injury?
- Is there a mesentery or in bone?
D: Disease
- Lund-MacKay stage
M: Maxillary sinuses (Haller cells)
P: Vertical height of the posterior ethmoid
What percentage of anterior ethmoid arteries are hanging (mesentery) and in bone?
Hanging: 40%
In bone (attached to skull base): 60%
Describe the Keros classification of the depth of the olfactory fossa
Keros classification: measures the height of the vertical lamella of the cribriform plate to the fovea ethmoidalis
Type 1: Depth 1-3mm
Type 2: Depth 4-7mm
Type 3: Depth 8-16mm (greatest risk of intraoperative CSF leak, AEA injury if hanging, orbital injury, or iatrogenic frontal sinus obstruction)
Type 4: Asymmetric
Kevan page 54
What are 11 predictors of poor outcome or recurrence after FESS?
- Smoking
- AERD (Samter’s triad)
- Cystic fibrosis/primary ciliary dyskinesia
- Poor treatment compliance
- Significant nasal polyposis / extensive disease on pre-op CT
- Atopy (asthma, atopic dermatitis)
- Immunodeficiency
- Fungal disease
- Previous surgery
- Depression
- Female gender (higher SNOT-22 scores)
What are intraoperative and postoperative management steps for dealing with medial orbit wall compromise/orbital fat herniation during FESS?
- Avoid suction or manipulation at the site of injury
- If a small defect, can be carefully avoided and surgery can proceed
- If a large defect, consider aborting surgery
- Avoid nasal packing (may result in intraorbital bleed)
- Ophthalmology consult if consdered
- No nose blowing for 2 weeks post-op (avoid pneumo-orbita)
- Exposed fat will re-mucosalize within 2 weeks
What are the AAO-HNS indications for image-guidance in FESS? 7
- Revision sinus surgery
- Distorted sinus anatomy (either developmental, postoperative, or traumatic)
- Extensive sinonasal polyposis
- Pathology involving frontal, posterior ethmoids/sphenoid sinuses
- Disease abutting skull base, orbit, optic nerve, or carotid
- CSF rhinorrhea or skull base defects
- Benign or malignant sinonasal tumors
“TRACE IT”
Tumor
Revision
Abutting CB/optic/orbit/carotid
CSF leak or skull base defect
Extensive nasal polyposis
In the frontal/sphenoid/post-ethmoid
Twisted (distorted anatomy)
What are contraindications to an endoscopic approach for resection of sinonasal tumors? 6
Contraindication: Tumor is not completely accessible via an endonasal approach
Examples:
1. Hard palatal involvement
2. Periorbital involvement
3. Intracranial involvement
4. Infratemporal fossa involvement
5. Cutaneous skin involvement
6. Extensive frontal sinus involvement