Finite Element Analysis of a PTFE Felt Interposition Pad for Relieving Vascular Compression of the Trigeminal Nerve.

Vascular compression of the trigeminal nerve is considered a major pathological factor in trigeminal neuralgia, a debilitating facial pain disorder. This study presents a contact mechanics analysis of the interaction between the blood vessels, particularly the superior cerebellar artery, and the trigeminal nerve. Using finite element method (FEM), the mechanical stresses acting on the nerve at the root entry zone, a common site of neurovascular compression, were investigated. The results indicate that vascular contact generates significant local compressive stress on the trigeminal nerve. Further FEM analysis predicts that polytetrafluoroethylene (PTFE) felt interposition substantially reduces contact compressive stress. Under the material properties and loading conditions adopted in the present model, the compressive stress acting on the trigeminal nerve was reduced by ~95%. Sensitivity analyses demonstrated that the qualitative conclusion of substantial stress reduction remained unchanged over a plausible range of nerve elastic moduli and contact friction coefficients. The proposed model provides a biomechanical framework for understanding neurovascular compression and the mechanical effects of PTFE felt interposition. In addition, the model may serve as a useful tool for evaluating the influence of interposition material properties and optimizing decompression strategies in microvascular decompression (MVD) surgery.