INTERCONNECTING THE POSTERIOR AND MIDDLE CRANIAL FOSSAE FOR TUMORS THAT TRAVERSE MECKELS CAVE

Meckel's cave is an avenue for tumor to spread between the posterior a nd middle cranial fossae. The most common neoplasms that traverse this channel are trigeminal schwannomas and meningiomas. The classic appro ach to address disease in both cranial fossae involves separate cranio tomies. Recent innovations in skull base surgery have made it possible to perform a single opening with simultaneous exposure of the posteri or and middle fossae, without undue brain retraction. Tumors with a la rge middle fossa component and a smaller posterior fossa portion are e xposed via subtemporal craniotomy with petrosectomy and tentorium divi sion. However, tumors with a large posterior fossa component and a sma ller middle fossa portion in the setting of serviceable hearing are ad dressed with retrosigmoid craniotomy and petrosectomy. For bilobed tum ors with substantial components in both fossae, subtemporal craniotomy combined with varying degrees of transtemporal petrosectomy and tento rium division is employed. The evolution of techniques to address tumo rs that traverse Meckel's cave is reviewed and a treatment algorithm i s proposed.