Expanded polytetrafluoroethylene membrane for the prevention of peridural fibrosis after spinal surgery: an experimental study.

One of the most common complications of lumbar spine surgery is peridural fibrosis, a fibroblastic invasion of the nerve roots and the peridural sac exposed at operation. Peridural fibrosis may produce symptoms similar to those the patient experienced preoperatively and, if another spinal operation is necessary, may increase the risk of injury at reexposure. In a controlled study in dogs, we assessed the use of expanded polytetrafluoroethylene (ePTFE) as a barrier to postoperative invasion of fibrous tissue into the laminectomy defect. In 14 dogs, a two-level laminectomy was done, at L4-L5 and L6-L7. In 12 dogs, an ePTFE membrane was placed directly over the dorsal surface of the laminectomy defect at L4-L5 and within the defect (over the surface of the dura) at L6-L7. No material was implanted in two dogs (controls). Tissue for histologic studies was obtained from the controls and from ten dogs with the membrane 12 weeks postoperatively. Two dogs with the membrane underwent reoperation. The study found that there was no peridural fibrosis in seven of the ten specimens in which the ePTFE membrane had been placed directly on the dorsal surface of the laminectomy defect, some peridural fibrosis in all specimens in which the membrane had been placed within the defect, and extensive fibrosis in controls. The ePTFE membrane created an excellent plane of dissection for reoperation. No foreign-body reactions to the membrane or membrane-related infections occurred. We conclude that the ePTFE spinal membrane, when properly implanted, is an effective barrier to postsurgical fibrous invasion of the vertebral canal. Clinical studies of use of this material in spinal surgery are warranted.