VIVA – Anatomy – Rhinology Flashcards
Accessory maxillary ostia incidence?
10%
How do you manage Accessory maxillary ostia intraoperatively?
Join to main ostium to avoid re-circulation
Describe the Caldwell Luc procedure
Caldwell-Luc operation is a process of opening the maxillary antrum through canine fossa by sublabial approach and dealing with the pathology inside the antrum.
- Incision. A horizontal incision with its ends upward is made below the gingivolabial sulcus, from lateral incisor to the 2nd molar. It cuts through mucous membrane and periosteum.
- Elevation of flap. The mucoperiosteal flap is raised from the canine fossa to the infraorbital nerve avoiding injury to the nerve
- Opening the antrum. Using cutting burr or gouge and hammer, a hole is made in the antrum. Opening is enlarged using Kerrison’s punch.
- Dealing with pathology. Once maxillary antrum has been opened, pathology is removed. Diseased antral mucosa can be removed with elevators, curettes and forceps. Cyst, benign tumour, foreign body or a polyp is removed .
- Making nasoantral window. A curved haemostat is pushed into the antrum from the inferior meatus and then this opening is enlarged with Kerrison’s and sidebiting forceps to make a window, 1.5 cm in diameter.
- Packing the antrum
Indications Caldwell Luc procedure?
Adjunct to transnasal removal of benign tumours such as inverting papilloma, JNA
Chronic intractable maxillary sinusitis with failed endoscopic management
Antrochonal polyp with failed endoscopic management
Biopsy of malignant masses
Open reduction and repair of orbital floor #
Access to pterygopalatine fossa, trans-antral sphenoidotomy, orbital decompression
Removal of odotogenic tumours and cysts
How is this different to canine fossa trephine?
Removal of the anterior wall of the maxilla, as in a Caldwell-Luc technique, gives superb access but has a very high risk of complications, particularly infraorbital hypes- thesia, dental or lip pain, and numbness. The creation of additional incisions, increased discomfort, bleeding, and the potential for cosmetic deformities have discouraged sur- geons from using this approach. Canine fossa trephine involves single hole into maxillary sinus without removing all of ant wall
What are the attachments of the uncinate process?
Sickle shaped bone extending from frontal recess superiorly and IT inferiorly
Middle and horizontal portions attach to lacrimal bone, frontal process of maxilla and ethmoidal process of IT
What are the variations of the sup attachment of the uncinate process inc%?
Insertion on to LP, BOS, MT
70-80%, 10, 5-10%
What is the recessus terminalis?
Ethmoid infundibulum terminates in blind recess known as RT when superior attachment of the uncinate is to LP
What are the variations in the anatomy of the uncinate process?
Attachment of uncinate to MT pushes frontal drainage pathway posteriorly
What is silent sinus syndrome?
Constellation of progressive enopthalmos and hypoglobus due to gradual collapse of orbital floor with opacification of maxillary sinus, in presence of subclinical maxillary sinusitis
Pathogenesis of silent sinus syndrome?
Occurs secondary to maxillary sinus hypoventilation due to obstruction of OMU à resorption of gases into capillaries of closed sinus cavity à negative pressure à accumulation of secretions with chronic subclinical inflamm à maxillary atelectasis and wall collapse
Treatment of silent sinus syndrome?
- endoscopic surgery to re-establish maxillary aeration and drainage
- orbital repair can be staged
Why is FESS dangerous in silent sinus syndrome?
Uncinate retracted laterally and atelectatic – possibility of injuring orbit
What is the hiatus semilunaris?
Two-dimensional cleft between the concave free posterior border of the uncinate process and the convex anterior surface of the ethmoidal bulla.
Define the Osteomeatal complex
OMC is a functional entity that included middle turbinate, uncinate process, ethmoid bulla, semilunar hiatus and ethmoid infundibulum.
OMC is final common pathway for drainage and ventilation of frontal, maxillary sinuses and ant.ethmoidal cells.
OMC is related with pathogenesis of nasal sinusitis and it is basis of functional nasal endoscopic surgery.
What are the boundaries of the infundibulum?
3 dimensional space in the lateral wall of the nose.
- Lateral wall = lamina papyracea, frontal process of the maxilla +/- lacrimal bone.
- Anterior border is formed by the acute angle the uncinate forms with the lateral wall of the nose.
- Bony defects in the region of the attachment of the uncinate to the inferior turbinate are closed in by periosteum and mucosa and form the anterior fontanelle.
- The medial wall of the infundibulum is formed by the uncinate process.
- The posterior border of the ethmoidal infundibulum is the anterior surface of the ethmoidal bulla.
- Superiorly, the configuration of the ethmoidal infundibulum and its relationship to the frontal recess depend on the attachments of the uncinate process.
- Uncinate process attaches to the lamina papyracea,
- Ethmoidal infundibulum is closed superiorly
- Infundibulum and the frontal recess are separated from each other and the frontal recess opens into the middle meatus between the uncinate and the middle turbinate.
- Uncinate process can attach to the roof of the ethmoid or to the middle turbinate à in both of these cases the frontal recess will open directly into the ethmoidal infundibulum.
- Uncinate process attaches to the lamina papyracea,
Name the lamella of the ethmoid bone in order
Vertical, Grand, Horizontal
Draw the lateral nasal wall & Label the bones forming it
Define the following cells : Agger Nasi
The most anterior ethmoidal cell
Found anterosuperior to the attachment of the middle turbinate to the lateral nasal wall
Posterior wall of the agger nasi cell usually forms the anterior wall of the frontal recess
Present in 93-98%
Define the following cells - Kuhn
Frontal cells – see below
Define the following cells - Suprabullar
Cells above the BE that don’t enter the frontal recess
Define the following cells - Haller
Anterior Ethmoidal cell pneumatising into the maxillary sinus above the ostium
Incidental finding in 45%
Can obstruct osteomeatal complex
Define the following cells - Onodi (inc Incidence?Significance?)
A posterior ethmoid cell that pneumatises into the superolateral aspect of the sphenoid sinus.
May result in pneumatisation around the ICA / Optic nerve
Seen in 9-12%
If present can place optic nerve at risk
Concha bullosa
Pneumatised MT
How do you perform a sphenoidotomy?
- Enter via posterior ethmoids OR nasal cavity medial to the superior turbinate
- Landmarks
- Superior turbinate
- May need to remove lower 1/3-1/2
- Superior turbinate
- Palpate natural ostium
- Aim to enter inferomedially
- Cannulate Os initially to locate
- Enlarge with an appropriate instrument
- Sphenoid punch (Less traumatic)
- Kerrison punch (Increased risk of unpredictable fracture)
- Avoid aggressive inferior enlargement to avoid pterygopalatine neurovascular bundle
May need to bipolar septal branch of SPA
Landmarks in FESS: skull base, orbit, sphenoid?
What are the surgical approaches to the sphenoid?
Transethmoid – as above
Transnasal
- medial to MT
- generally only used for pituitary or isolated sphenoid disease
Transeptal
- can be done by sublabial incision or hemi-transfixion
- Hardy’s self-retaining speculum
Name the Kuhn classification for frontoethmoidal cells
How is the modified Kuhn classification different?
Frontoethmoidal cell – AE cell that needs to be in close proximity (touching) frontal process of maxilla
Discuss the surgical approaches to the frontal sinus
- Aim is to clear the ethmoid air cells surrounding the frontal recess whilst preserving the mucosa of the recess to limit subsequent stenosis
- Use thru-cutting instruments
- Pass frontal sinus ball probe into drainage pathway
- Remove cells surrounding drainage path
- Keys
- Don’t prod medially as the lateral lamella of the cribiform plate is awaiting
- Regular reassessment of anatomical location / lamina papyracea
- Mini-trephine can aid in localizing the drainage pathway
- Use fluorescein dye to identify
- Consider using mucosal flaps to avoid circumferential raw bony edges
- Middle turbinate flap
- Axillary flap
- Uncinectomy / MMA
- Allows identification of lamina
- Identify the skull base
- Ethmoidectomy
- Sphenoidotomy. Then bring dissection forward along the skull base
- Note the position of the anterior ethmoidal artery
- Axillary flap
- Incision 8mm above axilla and bring forward 8mm
- Turn incision vertically down to level of axilla
- Carry incision back to root of MT
- Raise full thickness mucosal flap
- Open axilla with Hajek-Koeffler punch
- Remove anterior wall Agger Nasi Cell
- Pass probe up frontal drainage pathway
- Remove cells obstructing pathway
- Replace axillary flap to cover exposed bone around frontal recess
Describe the technique for frontal trephination
- Assess extent of frontal sinus and pneumatisation via CT scan
- Check for dehiscences in to posterior table as this influences ability to instill fluid into the sinus
- Incision along medial aspect of eyebrow
- Landmarks
- Horizontal line between medial aspects of either eyebrow
- Along above line, incise 1cm lateral to midpoint of above line
- Can modify site to match a skin crease or eyebrow as frontal skin is mobile
- LA
- Stab incision with 15 blade down to bone
- Dilate incision with artery forceps
- Place mini-trephine guide
- Engage guide on bone (it has teeth on it’s base)
- With guide in position commence drilling
- Drill for short bursts and remove from guide to irrigate
- Burr is 11mm long and should not penetrate posterior table
- If bone is too thick, move inferiorly as it tends to thin in this direction
- Remove trephine drill and keep guide in place once into frontal sinus
- Pass wire stylet into frontal sinus
- Place frontal cannula in a rotating fashion
- Once positioned, aspirate he sinus with a half filled syringe (Saline 500ml + Fluourescein 0.5ml 5%)
- Clear fluid = CSF
- Air / pus / blood= Sinus
Describe the Draf classification for approaches
- Draf I
- Complete removal of anterior ethmoid cells
- Complete removal of uncinate process
- Removal of obstructing frontal cells
- Draf IIA
- Frontal sinusotomy
- Removal of ethmoid cells obstructing frontal sinus drainage pathway
- Resection of floor of frontal sinus between lamina and Middle turbinate
- Frontal sinusotomy
- Draf IIB
- Frontal sinusotomy
- Resection of floor of frontal sinus from lamina to nasal septum
- Frontal sinusotomy
- Draf III
- Aka Endoscopic Modified Lothrop Procedure
- Resection of floor of frontal sinus both sides
- Resection superior part adjacent nasal septum
- Reection of inferior area of interfrontal septum
- Aka Endoscopic Modified Lothrop Procedure
What are the key steps for a Modified endoscopic Lothrop procedure
- Image guidance
- Revise maxillary, ethmoid and sphenoid sinuses
- Infiltrate LA into middle turbinate, axilla, septum
- Remove mucosa
- Above MT to roof of nose with microdebrider
- Create Septal Window
- Remove mucosa and Septum anterior to MT adjacent roof of nose over 3 x 2cm region
- Place bilateral frontal sinus mini-trephines
- Dissect bone anterior to the ostium
- Remove frontal process of maxilla with cutting burr
- Define lateral extent by exposing a small amount of skin
- Continue until floor of frontal sinus is entered
- Repeat on other side
- Drill medially until intersinus spetum is reached
- Remove the intersinus septum up to roof of frontal sinus
- Remove anterior frontal bone until there is no remaining lip
- Remove bone over forward projection of the skull base
- “Frontal T” formed by MT attachment to septum
- Drill posteriorly towards skull base
- Lower to level that doesn’t expose dura of olfactory fossa
- Suction bipolar haemostasis
- Harvey “Outside In” Technique
- 0 deg scope, head extended
- Septal window
- Identify 1st olfactory neuron
- Identify lateral extent of dissection via drilling down to nasal bone periosteum / skin
- Remove bone in between with a diamond burr
- Makes it faster and safer
Describe the technique for performing Osteoplastic flap
- Incision
- Brow, Mid-brow or Coronal
- All can be unilateral or bilateral
- Develop a superiorly based skin flap above the periosteum layer
- Incise superior, medial and lateral periosteum around the frontal sinus borders (Via template / illumination / navigation)
- Preservation of the inferior periosteum is key as it is the source of the blood supply
- Elevate periosteal edges to allow access for the saw / drill
- Pre-position bony plates
- Bevel bony incision towards sinus cavity
- Pass a few mm below the level of the hinge point
- Reflect flap of bone and periosteum
- Address frontal sinus disease as needed
- Try to preserve mucosa unless obliteration planned
- Replace flap
- Close periosteum with absorbable monofilament
- Close skin in 2 layers
- Tips and Pearls
- Can use a template of the frontal sinus cut from radiographs
- Leave periosteum attached to the bone of the anterior table
- Periosteum acts as a hinge inferiorly
- Bevel the bone incision towards the sinus
- Don’t shave eyebrows, as they may not return
Describe the technique for performing Frontoethmoidectomy
- establishes communication between the floor of the frontal sinus and the anterior ethmoid cells, in effect marsupializing the most anterior of the paranasal sinuses with the middle meatus
- efficacy is based on re-establishment of the integrity of drainage of the frontal sinus into the middle meatus à despite many adjunctive techniques developed to maintain patency of the nasofrontal duct, the Lynch procedure is associated with an unacceptably high degree of recurrence of frontal obstruction, mucocele formation, and sinusitis à may be used in patients who are not candidates for an endoscopic Draf or Lothrop procedure because of anatomic limitations
- temporary tarsorrhaphy
- incision is made above the medial aspect of the upper eyelid, curved, and then carried inferiorly down to the level of the medial canthus
- periosteum is elevated posteriorly, and a cutting burr is used to trephine the frontal sinus
- Kerrison rongeur is used to provide communication between the floor of the frontal sinus and the anterior ethmoid air cells, which are removed until free communication with the middle meatus is obtained.
- Diseased mucosa is removed from the frontal recess as completely as possible
- attempt must be made to reconstruct the nasofrontal duct with a nasoseptal mucosal flap à unnecessary when treating patients for fractures of the anterior wall of the frontal sinus or during removal of osteoma because the duct should not be traumatized and one would hope that it will return to its premorbid condition
Describe the technique for performing Reidel’s procedure
Removal of ant frontal sinus wall and its floor + obliteration
- Coronal Flap
- Can use an eyebrow incision
- Make initial hole in the medial 1/3 of the sinus
- Can shine an endoscope transnasally to aid identification
- Drill out around outline of the sinus
- Fix miniplate in position prior to removal of the anterior wall
- Drill walls with a diamond burr to ensure mucosa obliteration
- Take care around floor of frontal sinus as bone is thin and orbital entry a risk
- Place fascia lata of fat to obliterate the cavity
- Bony plate re-attached
- Pericranium and coronal flap replaced
- Bandage for 3/7
What is a frontal rescue procedure?
FESS approach to correct iatrogenically scarred and obstructed frontal recess, which cannot be successfully opened via normal endoscopic frontal sinus approach
Used primarily when only remaining option is ML or obliteration
Mucoperiosteal flap advancement to minimize stenosis
Generally after MT has been amputed and lateralises
Isolate MT stump and elevate mucoperiosteum off both sides
Bone and medial mucoperiosteum removed
Frontal sinus opened and flap of mucoperiostum rotated up
Discuss the grading for the depth of the skull base in FESS
Keros Classification of the Relationship between the Cribiform plate and Fovea Ethmidalis
- Keros 1 = Fovea Ethmoidalis 1-3mm above cribiform plate
- Keros 2 = 4-7mm
- Keros 3 = 8-16mm
The relevance is that the longer the lateral lamella (Higher Keros score) the higher the risk of inadvertent injury to the skull base
What is the thickness of the lamina cribrosa?
0.05-0.2mm
Describe the pathway of the anterior ethmoidal artery and branches? Where is it situated within the nasal cavity?
- Arises from Ophthalmic Artery (ICA) in the orbit
- Passes between superior oblique and medial rectus within the orbit
- Enters Ethmoid sinuses via anterior ethmoidal foramen within the frontoethmoidal suture (96%)
- 24mm posterior to lacrimal crest
- 14 to 35 mm from the optic canal
- 24mm posterior to lacrimal crest
- Crosses the sinus in a thin bony channel (the orbitocranial canal)
- Up to 1/3 on a mesentery
- Typically located posterior to the frontal recess
- Usually just posterior to frontal sinus ostium
- Runs inferiomedially to olfactory fossa passing thru lateral lamella
- The artery then turns anteriorly in a groove in the lateral lamella called the ethmoidal sulcus.
- At this point the artery gives off the anterior meningeal artery and reaches the nasal cavity through the cribriform plate.
- In the nasal cavity it divides into
- Anterior nasal artery (superior, lateral and medial branches)
- Posterior branch
- External nasal artery
- Several small meningeal branches.
- This division may take place before of after its passage through the cribriform plate.
The anterior ethmoidal artery is absent 7% to 14% of the time
When isn’t AEA “one cell back”?
Endoscopically follow ant surface of ethmoidal bulla in direction of roof of ethmoid – if bulla extends to roof of ethmoid the AEA can be found immediately adjacent to this point, usually 1-2mm posteriorly, else in suprabullar recess à frontal recess
How do you identify AEA on CT?
Kennedy’s nipple at posterior globe
Draw the landmarks seen in the sphenoid sinus
- Lateral wall has 4 prominences and 3 depressions
- Prominences (Sup to inf)
- Optic nerve
- Parasellar ICA
- V2
- Vidian (medial in floor)
- Depressions
- Lateral opticocarotid recess
- Depression between the cavernous apex and maxillary nerve
- Depression between V2 and Vidian
- Prominences (Sup to inf)
Draw the nasal septum
What are the deformities that lead to a twisted nose?
- Figure 37-19.
- A variety of nasal deformities, including the anatomic components involved. Each anatomic component of the deviated or twisted nose influences the remaining components, particularly those immediately adjacent, just as each step of the surgery influences the other steps.
- A,Deviation of the entire nose, including the nasal bones up to the radix.
- B, Twisted nose with the tip and caudal septum returning to the midline. The nasal bones are deviated from the midline up to the radix. The greatest convexity or concavity of the bony and cartilaginous vaults is frequently at their junction.
- C, Deviation of the cartilaginous components of the nose, including the septum, with caudal dislocation off the anterior spine.
- D, Deviation of the dorsal septum and septal angle, with the remainder of the nose in the midline. This creates distortion of the lower lateral cartilage, with actual or simulated asymmetry.
- E, Deviation of the dorsal septum and septal angle with the distortion of the entire tip of the nose and medial crura
What are the following? What is the usual measurement?
Mentocervical
- Angle defined by glabella-to-pogonion line intersecting with menton-to-cervical point line
- 80-95 degrees
What techniques are available for addressing nasal dorsal hump?
· Access
o Intercartilaginous or transcartilaginous incision continued around to a 4-6mm high, partial transfixion septal incision
o Sharp dissection into plane immediately above perichondrium, then incise and elevated the periosteum.
o Converse retractor and headlight
Figure 45-47 A, Sharp knife elevation of soft tissues over cartilaginous dorsum should be accomplished in the favorable tissue plane intimate to the cartilaginous pyramid to reduce scarring and bleeding. B, Elevation of the periosteum with a knife initially followed by a Joseph periosteal elevator finalizes décollement of nasal soft tissues. Inclusion of periosteum in skin flap creates additional thickness of the covering skin mantle, cushioning and camouflaging any possible irregularities in bony healing.
- Cartilaginous profile adjustment
- Bilateral submucoperichondrial tunnels and separation of ULC from septum
- Equal or less resection of ULC with respect to septum to achieve rounding of dorsum and avoid inverted V + preserve internal nasal valve
- Knife placed at osseocartilaginous junction and drawn down to the anterior septal angle – 11 Blade
- Make sure you palpate the dorsum and the tip in between each removal to ensure the proper tip-supratip relationship created.
- Try to protect the mucoperichondrium connecting the upper laterals to the quadrangular cartilage (important in internal nasal valve support).
- If resecting large amts à consider spreader grafts
- Bony hump removal
- Elevate perichondrium off with a Joseph elevator
- Limited elevation results in less bleeding and stabilization of fragments
- Rubin osteotome à conservative removal of hump
- Inspect the upper laterals to make sur they don’t sit above the quadrangular cartilage àcan get caught in rasps and à avulsion of cartilage from nasal bones { Difficult to repair}.
- Raspsà down or up cutting – remove irregularities
- Double-action Becker scissors
- Profile must be smooth and free of irregularities.
- Final finishing with the more delicate tungsten-carbide rasp
- Creates an ‘open-book deformity
- Complications
- Inadequate removal
- Over removal
- Open-roof deformity
What are the following deformities? Polybeak
- Post-operative fullness of the supratip, with an abnormal tip-supratip relationship
- Thick, stiff skin-soft tissue envelope may not drape smoothly
- Crucial to understand what caused to treat effectively à palpate
- Causes:
- Failure to maintain adequate tip support à loss of tip projection
- Rxà columellar strut may help
- Inadequate cartilaginous hump removal
- Rxà resect more dorsal septum
- Supratip dead space or scar formation – poor draping of thin skin envelope
- Rxà scar: steroid injection, skin taping
- Failure to maintain adequate tip support à loss of tip projection
What are the septal supports?
- The septum is the main support structure of the external nose.
- Supporting and nonsupporting parts of the nasal septum are divided by a vertical line dropped from the nasal process of the frontal bone to the anterior nasal spine
- Septal components posterior to this line contribute little to nasal support and can be sacrificed with less concern than anterior structures
- Line of nasal support
- Supports
- Dorsal and caudal struts
- Keystone area
- Anterior nasal spine
Osteotomies - Types?
Medial
Lateral
Intermediate
Describe your technique for Osteotomies - Lateral
· Reserved for last as more traumatic than previous steps.
· Additional tip refinement, septal reconstruction, or alar base surgery done first.
· 2-3mm osteotomes à less trauma
· Keeping the periosteum intact stabilizes and internally splints the completed fractures.
· Method:
o Low-curved lateral osteotomy initiated by pressing osteotome thru vestibule skin to engage the piriform aperture at or just above the inferior turb.
- Placing the initial osteotomy lower on the lateral wall or onto the floor à no cosmetic improvement and may compromise the lower nasal airway.
- Progress toward face of the maxilla
- Follow along nasomaxillary crease
- Avoid going high and creating a step-deformity
- Guarded curved osteotome: Nievertz
- Along nasomaxillary junctionà not too high (near the dorsum) as will -> step deformity.
- Encounter the previously done medial-oblique osteotomy
- Apply immediate finger pressure to prevent any haematoma formation.
- Infracture
- Bones should be freely mobile but splinted by periosteum and soft tissues.
- Re-examine the dorsum/upper laterals to see if any new irregularities now evident.
- Can actually do intermediate osteotomies if the bony sidewalls are grossly twisted or asymmetric, but must be done before the lateral ones are completed.
What are the indications for Tip delivery? Tip non delivery?
What are the causes and solutions for the following tip problems?
Hanging columella
Retracted ala or alar notching can give the appearance of a hanging columella and must be differentiated, because the etiology and surgical repair are different
Anatomic configurations that make up the hanging columella deformity include
- overdevelopment of the caudal septal cartilage, which pushes down the medial crura
- redundant membranous septum
- medial and intermediate crura can be too wide, excessively curved and convex, or vertically inclined à long medial crus, with an excessive C-shaped curvature, has been cited as a prominent cause of the hanging columella deformity.
