Interconnecting the posterior and middle cranial fossae for tumors that traverse Meckel's cave
Cranial Fossa, Posterior
Meckel's cave is an avenue for tumor to spread between the posterior and middle cranial fossae. The most common neoplasms that traverse this channel are trigeminal schwannomas and meningiomas. The classic approach to address disease in both cranial fossae involves separate craniotomies. Recent innovations in skull base surgery have made it possible to perform a single opening with simultaneous exposure of the posterior and middle fossae, without undue brain retraction. Tumors with a large middle fossa component and a smaller posterior fossa portion are exposed via subtemporal craniotomy with petrosectomy and tentorium division. However, tumors with a large posterior fossa component and a smaller middle fossa portion in the setting of serviceable hearing are addressed with retrosigmoid craniotomy and petrosectomy. For bilobed tumors with substantial components in both fossae, subtemporal craniotomy combined with varying degrees of transtemporal petrosectomy and tentorium division is employed. The evolution of techniques to address tumors that traverse Meckel's cave is reviewed and a treatment algorithm is proposed.