Anatomy of the Fibrofatty Adhesion Related to the Frontozygomatic Process for Suprafascial Dissection of the Pterional Scalp Flap: A Cadaveric and Clinical Study.

Background: With the existence of the fibrofatty adhesion (FFA) in the temporal region in relation to the frontotemporal branch of the facial nerve, the suprafascial dissection technique for two-layer pterional scalp flap creation was developed for standard pterional craniotomy. However, the exact anatomy of the FFA has not been well described. We clarified the anatomy of the FFA in cadavers and clinical cases.

Materials and methods: Fourteen sides of the cadaveric head were dissected, and the location of the FFA was measured. Twenty patients with cerebral aneurysm who underwent pterional craniotomy using the suprafascial dissection technique between December 2023 and January 2025 were retrospectively reviewed and evaluated for the location of the FFA.

Results: In the cadaveric study, the mean distances between the superoposterior border of the FFA and the junction of the frontozygomatic process (FZP) and zygomatic arch were 2.2, 2.1, and 2.5 cm at the posterior, superoposterior, and superior borders of the FFA, respectively. The superior edge of the FFA was located inferior to the junction of the FZP and the temporal line at 2 and 1.8 cm on average for the cadaveric and clinical study, respectively.

Conclusion: The FFA was located in a small area posterior to the FZP, superior to the zygomatic arch, and below the junction of the FZP and the temporal line. The existence and anatomy of the FFA confirmed the safety of suprafascial dissection for pterional craniotomy. When exposing the zygomatic arch is necessary, interfascial or subfascial dissection must be performed.