Retrosigmoid approach to the posterior and middle fossa

Abstract

Since the fi rst description of the unilateral approach to the cerebellopontine angle (CPA) in 1903 by Fedor Krause [ 2, 3 ], several techniques were developed by Cushing [ 4 ], Seiffert [ 5 ], Dandy [ 6 - 8 ], House [ 9, 10 ], and Fisch [ 11 ], among others, in order to access the CPA structures. The surgery of the CPA is ruled by three approaches as follows: the transtemporal extradural approach, the transmastoid translabyrinthine approach, and the lateral suboccipital or retrosigmoid approach [ 12 ]. The retrosigmoid approach provides a wide exposure of the CPA structures [ 1, 12 - 15 ] and may be extended inferiorly through the far-lateral transcondylar approach [ 13 ] and far-lateral retrocondylar approach [ 1, 16 ] or superiorly through the retrosigmoid intradural suprameatal approach (RISA) [ 15, 17 - 19 ]. Extensive skull base approaches may greatly increase the surgical morbidity and consequently the risks of postoperative neurological defi cits [ 1 ].