Fisch Type C versus an Endoscopic Endonasal Approach to the Petrous Carotid Artery: Indications, Limitations, and Examples

Background Addressing lesions of the infratemporal fossa (ITF) requires assessing the relationship of the pathology relative to key anatomical structures, most importantly the internal carotid artery (ICA). Although the Fisch Type C approach remains the gold standard for access to the lateral skull base, advances in endoscopic endonasal approach (EEA) techniques and equipment currently allow for expanded endoscopic exposure and access to the ITF.

Objectives This study compares the Fisch Type C approach and EEA to the ITF. Benefits and limitations of both approaches are explored.

Methods Both Fisch Type C approach and EEA to the ITF were performed in cadaveric specimens. The exposures provided were analyzed and compared using high-definition photography. Two clinical cases are presented to exemplify technique and appropriate selection of these approaches.

Results Both the Fisch Type C approach and the EEA allow for wide exposure of the ITF. The Fisch Type C approach provides early lateral identification of the ICA and ultimately provides access to the nasopharynx, sella, and eustachian tube. The EEA provides early nasopharyngeal/eustachian tube exposure. Subsequent identification of the vidian canal, foramen ovale, and foramen spinosum is achieved prior to lateral dissection of the petrous carotid.

Conclusion Both the Fisch Type C approach and the EEA allow for exposure of the petrous ICA and access to the ITF. The ultimate choice of surgical approach depends on the degree of ICA involvement, lateral extent of the disease, malignant versus benign nature of the disease, and patient expectations.