Table 2.

Outline of available approaches highlighting advantages and risks as well as potential complications

		Portion MC access	Advantages	Structures at risk/complications	Limits
Anterio-medial	Transpterygoid	Antero-medial inferior	No brain retraction	CSF leak, vidian nerve/artery, corneal keratopathy, internal carotid artery	Content infratemporal fossa, region lateral and posterior to the GG
	Transantral/-maxillary	Antero-lateral	Less ICA/PPF manipulation	Oro-antral fistula, nasolacrimal duct	Posterior fossa
	Transorbital	Superior and anterolateral	Limited temporal retraction, no manipulation of PPF content	Orbital content, cranial nerves, M. levator palpebrae, CSF leak and pulsatile exopthalmus	Region medial to V1, posterior to ICA
	Percutaneous	Foramen rotundum	Minimal invasive	Internal maxillary artery, cranial nerves, e.g. trigeminal and oculomotor nerves	Lack of surgical field visualization
Antero-lateral	Pterional and orbitozygomatic extension	Antero-lateral-superior	Standard skull base surgery approach	Cranial nerve injury (III, IV, VI), temporal muscle disruption/translocation brain retraction	Inferior portion of MC
Lateral	Anterior petrosectomy	Lateral, dorsal	Posterior fossa extension, if required	Brain retraction, wide craniotomy, tentorial division, otologic structures, superior petrosal vein	Lower edge porus trigeminus, petrous ICA, inferior petrosal vein
Posterior	Retrosigmoid-suprameatal	Dorso-medial	Small craniotomy	Cranial nerve injury (VII-VIII), sinus sigmoideus, cerebellum retraction	Middle fossa

CSF cerebral spinal fluid, ICA internal carotid artery, GG Gasserian ganglion, MC Meckel’s cave, PPF pterygopalatine fossa