Quantitative Determination of the Optimal Temporoparietal Fascia Flap Necessary to Repair Skull Base Defects

Objective The ability to reconstruct large cranial base defects has greatly improved with the development of pedicled vascularized flaps. The temporoparietal fascia flap (TPFF) is a viable alternative to the Hadad-Bassagasteguy nasoseptal flap for large ventral skull base defects. This study aims to characterize the size of the flap necessary for optimal ventral skull base reconstruction.

Method A total of 11 formaldehyde-fixed cadaveric heads were used in this study. A TPFF of varying height and width was harvested on each side (22 total), and passed through the pterygomaxillary fissure to the ventral skull base to assess its coverage. The TPFF for a subgroup of 12 sides (six cadaveric heads) was then trimmed to determine the minimum height necessary for coverage.

Results The range of the TPFF height was 12.5 to 16.5 cm (mean: 14.72 cm). The mean width of the TPFF was 8.43 cm (SD: 1.01 cm). The mean distance from the TPFF pedicle through the pterygomaxillary fissure was 5.8 cm (SD: 0.50 cm). All TPFF flaps provided complete coverage of clival defects, and when rotated anteriorly provided coverage up to the cribriform plate. The subgroup analysis determined that the minimum height necessary for complete coverage of cribriform defects and ventral defects up to the planum sphenoidale was 12 cm (p < 0.01).

Conclusion The TPFF is a versatile alternative to the nasoseptal flap. A TPFF with a height of at least 12 cm should provide enough coverage for all ventral skull base defects.