Concepts in Endoscopic Endonasal Skull Base Surgery:

Choosing the right approach…

Open vs Endoscopic:

Lateral access limited by ICASkeletonization and lateralization of paraclival ICA

Risk of injury to ICA

Transpterygoid infrapetrous approachRisk of injury to Eustachian tube; sacrifice of vidian nerve

Retrosigmoid + EEA + GK

26 yo F with meningioma

Visual deterioration is 2x–5x more frequent in Transcranial than Endonasal approaches *

* Size comparison bias / Goal of surgery

Center # Pts

Preferred Approach GTR GTR

PrimaryGTR

RecurrentCSF leak Meningitis New

CN Recurrence Death/Dz Progression f/up

UPMC 60 EEA 66.7% 82.9% 44% 20% 3.3% 8.3% 33.3% 10% 17.8

Sen et al 2010 65 Lateral

and EEA 58% 64% 47% 21.5% 10.8% ? 49% 33.8% 66

Colli/Al Mefty 2001 53 Lateral 45.3% 44% 31.6% 12.2

% 1.9% 20.6% ? 17% 50

Gay et al 1995 46 Lateral 47% N/A N/A 30% 10% 80% 13% 10.8% 45

Tzortzidis 2006 74 Lateral 71.6% 83% 30% 1.35

% N/A 4% 35% 14.9% 96

Crockard 2001 42 Transoral 4.7% 4% 5.5% 21% 8% 12% ? ? 51

MRI: tumor in right lateral clivus with partial encasement of basilar artery and petrous ICA; extension to foramen rotundum and foramen ovale

Surgery: Endoscopic transclival, right transpterygoid, left transmaxillaryCTM allowed access as far as the parapharyngeal ICA

subtotal resection due to significant lateral extension of tumor

Postop Imaging: near GTR with possible small residual along the left lateral margin of the clivus and jugular bulb (ipsilateral to the transmaxillary approach)

(A)and (B) Preop MRI (C) and (D) Postoperative CT

POST-OPPRE-OP

EEA Open

PreOp

PostOp

porencephalic cave

EEA Open

PreOp

PostOp flair signal changeNeurocognitive function?