The Use of Preoperative 3D Volumetric Analysis of Buccal Fat Pad Flap in Determining Intraoperative Flap Reach: A Cadaveric Study

Objectives The buccal fat pad (BFP) harvested endoscopically can aid in the reconstruction of selected skull base defects. The volume of available buccal fat may not be consistent in every case. We aimed to determine if a greater volume of buccal fat calculated preoperatively based on CT imaging would correspond to a greater reach (length and/or width) of the flap intraoperatively.

Study Design Cadaveric study of 5 heads, 10 sides.

Methods Fresh-frozen cadaveric heads with CT imaging were evaluated using the OsiriX software to calculate the volume of the buccal fat on both sides. The BFP was then harvested endoscopically and measurements were taken for length and width of maximum reach. Two heads were also dissected via a transfacial approach to demonstrate the anatomy of the BFP.

Results The transfacial dissection demonstrated the lobes of the BFP well. On mobilizing the BFP endoscopically, most of the mobilization was limited to the posterior lobe, in particular, the temporalis and pterygoid components, with minimal to no displacement of the superficial lobe, which would minimize the risk of hollowing of the buccal fullness. The volume of the BFP ranged from 6.93 to 11.98 cm³. In all heads, there was no statistically significant difference in the volume of BFP between the right and left sides, except for one head. On endoscopic dissection of the BFP, the range of the maximum length of the flap was 3.3 to 5.8 cm. The width ranged from 0.7 to 2.0 cm. There was a positive correlation shown between the calculated volume of the BFP based on CT imaging and the dissected length and width of the flap (Pearson’s correlation, r = 0.83 and r = 0.80, respectively). In addition, we demonstrated a dissected BFP flap length of at least 5.0 cm in all cases, except for one, despite variances in the volume of BFP measured.

Conclusion Preoperative calculation of the CT-based volume of the BFP is a good predictor, and correlates positively with the intraoperative maximum reach of the flap for both length and width. Where the volume may be lower in some instances, the BFP would still have adequate reach to provide coverage for the lower and mid-clival region in most cases.