Comparison of Nerve Defect Reconstructions Committed by Placing Vascular Endothelial Growth Factor (Vegf) or Mesenchymal Stem Cells into the Vein Graft Lumen in Conjunction with Nerve Fragments

Introduction: Nerve graft use is considered as a gold standard method in nerve defect reconstruction. However alternative reconstruction methods are still being investigated due to the donor site morbidity caused by the harvest of the graft from a healthy nerve.

The aim of this study was reconstructing a nerve defect without causing morbidity by using a vein graft filled with nerve fragments, taken from the distal segment of the defect, in conjunction with either vascular endothelial growth factor loaded microspheres or mesenchymal stem cells.

Methodology and Material: After preparing the vascular endothelial growth factor loaded microspheres and bone marrow derived mesenchymal stem cells, 48 Sprague-Dawley rats were divided into six groups. In all groups 1.6 cm long defect was created on the peroneal nerves of the rats. Reconstruction methods employed to repair the defects were: I. Empty vein graft, II. Nerve graft, III. Nerve fragments including vein graft, IV. Nerve fragments and blank microspheres including vein graft, V. Nerve fragments and vascular endothelial growth factor loaded microspheres including vein graft, VI. Nerve fragments and stem cells including vein graft. The nerve fragments used in defect reconstruction were taken from the nerve segment at the distal end of the defect. At the 8th week after the reconstruction walking track analysis, nerve conduction studies were performed to all groups. Nerve biopsies were taken to count axons. Results were statistically compared.

Results: Statistically there was no difference between nerve graft group - nerve fragments and vascular endothelial growth factor loaded microspheres including vein graft group and nerve fragments including vein graft group - nerve fragments and blank microspheres including vein graft group. Most successful healing was determined in both nerve graft group and nerve fragments and vascular endothelial growth factor loaded microspheres including vein graft group. Second most successful healing was determined in the nerve fragments and stem cell including vein graft group.

Conclusions: Nerve fragments, taken from the segment distal to the nerve defect, was placed in the vein graft lumen in conjunction with vascular endothelial growth factor loaded microspheres. By means of this treatment method, which can be an alternative for autogenous nerve graft, without taking graft from a healthy nerve a successful nerve reconstruction was achieved.