Irreversible Electroporation of the Femoral Neurovascular Bundle: Imaging and Histologic Evaluation in a Swine Model

Purpose: To evaluate imaging, histologic changes, and safety of irreversible electroporation (IRE) on the femoral neurovascular bundle in a swine model.

Materials and methods: The study was approved by the institutional animal ethics committee. IRE was performed on the right femoral neurovascular bundle of 9 swine, which were subsequently sacrificed at 24 hours (n = 4, acute group), 7 days (n = 4, subacute group), or 21 days (n = 1, delayed group). Clinical observation, computed tomography (CT), and pathologic examination were carried out.

Results: After the procedure, 7 of 9 subjects were able to stand and walk, and the remaining 2 subjects could eventually do so within 1 week. The femoral vessels were patent on CT and gross examination. There was microscopic evidence of venous thrombosis in 75% of the subacute group. Except for mild perineural inflammation observed in 1 subject in the subacute group, the femoral nerves were intact on gross and histologic examination. Significant damage to the surrounding muscle and soft tissue was identified on CT and histology, manifesting as necrosis, hematoma, and inflammation.

Conclusions: The ablative effect of IRE on muscle and soft tissue manifested as necrosis, hemorrhage, and inflammation. Histologic changes were observed in the perineural tissue and veins in a few subjects. The clinical implication of such changes and safety of clinical use of IRE for lesions encasing the neurovascular bundle in humans are yet to be determined.