Determining the best graft-sealant combination for skull base repair using a soft tissue in vitro porcine model.

Background: The purpose of this work was to compare the absolute breaking strength of various soft tissue skull base (SB) repairs in an in vitro porcine model.

Methods: A burst pressure (BP) testing system was designed using an axial loading force to create increasing hydraulic pressure. Defects measuring 0.5 × 0.5 cm were created in fascia lata samples. Defects were repaired using various grafts (pericranium and 2 different dural substitutes, Alloderm(®) and Durasis(®)) measuring 1.0 × 1.0 cm to cover the deficient area. Grafts were further reinforced onto the fascia background with either fibrin glue (Tisseel(®)) or hydrogel sealant (DuraSeal™). Each combination of graft and sealant was conducted 6 times and tested 24 hours after the repair.

Results: The mean BP (±standard deviation [SD]) were as follows: DuraSeal™-Alloderm, 12.5 ± 5.8 mmHg; DuraSeal™-Durasis, 21.8 ± 20.7 mmHg; DuraSeal™-pericranium, 44.7 ± 30.1 mmHg; Tisseel-Alloderm, 30.6 ± 26.3 mmHg; Tisseel-Durasis, 15.8 ± 18.6 mmHg; and Tisseel-pericranium, 95.5 ± 86 mmHg. One-way analysis of variance showed that the strongest type of repair was Tisseel-pericranium when adjusting for the others (p < 0.0001). The difference in mean BP of repair with DuraSeal™ vs Tisseel(®) was not statistically significant (p = 0.22). Comparing sealants, the use of Alloderm(®) or Durasis(®) decreased the strength of the repair in comparison to pericranium (p < 0.0001). Bonferroni analysis showed a significant difference between pericranium and Alloderm(®) (p < 0.05) and between pericranium and Durasis(®) (p < 0.05) but not between Alloderm(®) and Durasis(®) (p > 0.05).

Conclusion: In this model, the strongest type of repair (pressure 6 times higher than normal intracranial pressure) was the combination of Tisseel(®)-pericranium. Our data will help guide surgeons who repair SB defects to choose the best graft and sealant.