Christos Georgalas PhD MRCS DLO FRCS(ORL-HNS)Consultant OtolaryngologistAcademic Medical Centre, Amsterdam

Access to the sphenoid

Sphenoidotomy

Sphenoid septae

Pre-clival carotid

Axial CTCoronal CT

Internal carotid is vulnerableInternal carotid is vulnerable

Axial CTAxial CT

Internal carotid may project and may not be covered by boneThe septae almost always end on the carotid canal

Septae

SphenoidectomySphenoidectomy

Internal carotid is vulnerable!!Internal carotid is vulnerable!!

Dehiscent carotid canal (8%)

Axial CT Axial CT !!!!!!

Onodi Cell

Posterior ethmoid cell that grows into the sphenoid cell and contains the optic nerve

Axial CT

Sagittal CT

Coronal CT

Sphenoid sinus

Surgery posterior ethmoidsSurgery posterior ethmoids

Optic nerve is vulnerable!Optic nerve is vulnerable!

Coronal CT

Axial CT

11 22

22

1. Projection of the optic nerve into the sphenoid sinus

2. Dehiscent optic nerve (4%)!!!!!!

Sphenoid surgerySphenoid surgery

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 15 angle with the horizontal ⁰plane 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.

CA

ON

. 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

CPS

Enlarge the sphenoid ostium

B. Use initially a Stammberger and subsequently a Kerrison punch – always working medially and inferiorly

A long way to go