Enabling Minimal Access for Middle Cranial Fossa Cerebrospinal Fluid Leak Repair via Optimal Craniotomy Centering: A Cadaveric Morphometric Study

Abstract To compare the morphometric exposure and surgical accessibility of key middle cranial fossa landmarks achieved by a temporal mini craniotomy centered at the root of zygoma (ROZ) and external auditory canal (EAC). Four freeze-preserved cadaver heads (8 sides) were utilized to perform bilateral dissections to expose the middle cranial fossa floor. A 3 cm × 3 cm temporal craniotomy was centered on the ROZ on one side and EAC on the contralateral side. Distances and angles of visualization from the lowermost aspect of craniotomy midpoint to the arcuate eminence (AE), tegmen tympani (TT), tegmen mastoideum (TM), and petrous apex (PA) were measured. Statistical comparison was done using the Mann–Whitney U test. All landmarks were identified. Craniotomy centered at the EAC aligned more directly with the AE and TM. Whereas craniotomy centered over the ROZ was in line of sight of TT and PA, reflected by more favorable visualization angles for the TT (p = 0.029). From the ROZ, the TM and AE were more posterior and from the EAC, TT, and PA were more anterior. However, distance measurements between groups did not reach statistical significance for AE, TM, or PA. Anatomically tailored centering of temporal craniotomy can facilitate minimal access approaches for repairing middle fossa defects. Craniotomy centered on the EAC favors access to defects in the TM and AE, while centering on ROZ aligns with the PA and TT. Our morphometric data can help standardize limited middle fossa craniotomy positioning.