Transcript frontal sphenoids

Access to the sphenoid
Christos Georgalas PhD MRCS DLO FRCS(ORL-HNS)
Consultant Otolaryngologist
Academic Medical Centre, Amsterdam
Sphenoidotomy
Sphenoid septae
Axial CT
Pre-clival carotid
Coronal CT
Internal carotid is vulnerable
Internal carotid may project and may not be covered by bone
The septae almost always end on the carotid canal
Axial CT
Axial CT
Sphenoidectomy
Septae
Internal carotid is vulnerable!!
Dehiscent carotid canal
(8%)
Axial CT
Axial CT
!!!
Onodi Cell
Sagittal CT
Axial CT
Sphenoid sinus
Surgery posterior ethmoids
Coronal CT
Posterior ethmoid cell that grows into the sphenoid cell and
contains the optic nerve
Optic nerve is vulnerable!
Axial CT
Sphenoid surgery
1
2
Coronal CT
1. Projection of the optic nerve
into the sphenoid sinus
2. Dehiscent optic nerve (4%)
!!!
2
Types of sphenoid
pneumatisation
A. Conchal)
B. Pre-sellar)
C.Sellar
Sphenoidotomy
• The anterior surface of the sphenoid sinus
is approximately 8 cm from the nasal
spine and at 15⁰ angle with the horizontal
plane of nasal cavity
The 3+1 ways to enter the
sphenoid
A. Superior turbinate
•
Lateralise gently medial turbinate
•
Posterior and superior to the middle turbinate you can visualise
the superior turbinate - Lateralise it!
•
Medially you will find the sphenoid
ostium
The 3+1 ways to enter the sphenoid
B. Nasopharynx- posterior choanae
•
Follow nasopharynx
•
Find posterior choanae –(exactly where the posterior
wall becomes from vertical horizontal)
•
1.6 – 2 cm above that you will find the ostium (4 – 5
times the width of a straight suction
The 3+1 ways to enter the sphenoid
C. Through the posterior septum – rostrum
(safer)
•
Remove the mucosa from the rostrum
•
Follow the bone laterally
•
The ostium is 0.5-1 cm from the septum
The 3+1 ways to enter the
sphenoid
And the less safe way
D: Through the posterior ethmoids
Perforate the posterior ethmoids aiming postero
medially – NOT recommended!!!!
Sphenoidectomy
The posterior septal brach of the sphenopalatine
artery runs on the frontal wall of the sphenoid –
risk of troublesome (but not dangerous) bleeding
The same branch is used for nasoseptal flap for
skull base defects reconstruction!
Enlarge the ostium in an inferior and medial direction with
Hayeck punch or drill
If necessary repeat procedure on other side and combine the
two enlarged openings medially. Remove distal part of the
bony septum.
ON
CA
. Identify the location of the optic nerve (ON) , carotid canal (CA)
and opticocarotid recess (OCR) along the lateral sphenoid wall
and sella (SE) on the posterior wall
Steps of Surgery
•
NASAL PHASE
– Diagnostic endoscopy
– Localising and opening sphenoid sinus ostium
– Preparing mucoseptal flap (if extended approach)
•
SPHENOID PHASE
– Widening of the ostium and exposure of sphenoid sinus
– Exposure of the anterior sellar wall
•
SELLAR PHASE
– Opening of the sella
– Incising the dura
– Tumor removal
– Closure of the sella
•
Completion of surgery (application of flap, closure, packs)
Finding the Sphenoid
•
Lateralize or remove lower half of
middle turbinate if necessary–
identify superior turbinate.
•
Inferomedially to the superior
turbinate is the sphenoid ostium.
•
The sphenoid ostium is 10-15 mm
above the choana
The pedicled nasoseptal flap
Hadad G, Bassagasteguy L, Carrau RL, Mataza JC, Kassam A, Snyderman CH, Mintz A.
A novel reconstructive technique after endoscopic expanded endonasal approaches:
vascular pedicle nasoseptal flap. Laryngoscope. 2006 Oct;116(10):1882-6.
Repeat on other side
Repeat procedure on other side
and combine the two enlarged
openings medially. Remove
distal part of the bony septum
and rostrum with blakesley,
punch or drill, depending on
consistency
Identify sella, carotid bulge, optic
nerve, opticocarotid recess
and planum sphenoidale –
rarely also vidian nerve
OCR
S
CP
Enlarge the sphenoid ostium
B. Use initially a
Stammberger and
subsequently a
Kerrison punch –
always working
medially and inferiorly
A long way to go