REROUTING OF THE INTRATEMPORAL FACIAL-NERVE - AN ANALYSIS OF THE LITERATURE

Anterior rerouting of the intratemporal facial nerve in the infratempo ral fossa approach is employed to access to the jugular bulb, hypotymp anum, and lateral skull base, whereas posterior rerouting of the facia l nerve, as employed in the transcochlear craniotomy, is most frequent ly used for surgery of the posterior fossa, cerebellopontine angle, pr epontine region, and petrous apex. Facial nerve rerouting may lead to facial paresis or paralysis. This review of the literature is intended to define the physiologic ''cost'' of these procedures, so that the n eurotologic surgeon can determine if the morbidity incurred in these t echniques is worth the resultant exposure. Inconsistencies in reportin g facial function places into question the validity of some of the cum ulative data reported. Postoperatively, grades I-II facial nerve funct ion was seen in 91% of patients undergoing short anterior rerouting, 7 4% of patients undergoing long anterior rerouting, and 26% of patients undergoing posterior complete rerouting. Although facial nerve rerout ing allows unhindered exposure to previously inaccessible regions, it is achieved at the cost of facial nerve function. Facial nerve dysfunc tion increases with the length of facial nerve rerouted.