[Prevention of epidural scar adhesion following lumb spine operation]

Four biomaterials including pork fat (PF), glutaradehyde crosslinked pork peritonium (GCP), glutaradehyde cross-linked human amnion (GCA) and freeze-dried human amnion (FDA) dura were compared for their ability to prevent the dura from adhesion in 24 dogs. Noncontiguous laminectomies were performed on each dog. Laminectomized areas where the above mentioned 4 materials put randomly were served as experimental groups while laminectomized areas with autologous fat transplants put in place were served as standard control and empty control was set with the area left untreated. The formation of fibrosis and the adhesion of the dura were evaluated at 1, 2, 3, 4, 6, 12 weeks after operation by using a double-blind protocol. Methods of observation included gross anatomical evaluation, histological evaluation, computer-assisted image analysis, fibroblasts counting and measurement of SCEP. The results showed: 1. The epidural scar arose from the raw surface of erector spinal muscles and the bony edges created by the procedure; 2. Putting a suitable obstructor between the dura and the erector spinae muscle would make dura be exempted from adhesion; 3. The interpositional membrane should be tucked in between the bony edges in close proximity to the bony surface without leaving any room; 4. GCA seems to be efficient in preventing dural adhesion and reducing the invasion of the scar tissue in the spinal canal.