Prevention of postlaminectomy epidural fibrosis using bioelastic materials.
METHODS
The use of elastic protein-based polymers for the prevention of epidural fibrosis following lumbar spine laminectomy was investigated in a rabbit model.


OBJECTIVE
To determine the safety and efficacy of two bioelastic polymers in matrix and gel forms as interpositional materials in preventing postlaminectomy epidural fibrosis.


BACKGROUND
Postlaminectomy epidural fibrosis complicates revision spine surgery and is implicated in cases of "failed back syndrome." Materials employed as mechanical barriers to limit tethering of neural elements by the fibrosis tissue have met with little success. A recent family of protein-based polymers, previously reported to prevent postoperative scarring and adhesions, may hold promise in treating this condition.


METHODS
Sixteen female New Zealand White rabbits underwent laminectomy at L4 and L6. Two polymer compositions, each in membrane and gel forms, were implanted at a randomly assigned level in four rabbits each, with the remaining level serving as an internal control. The animals were killed at 8 weeks, and qualitative and quantitative histology and gross pathologic examination were performed for both the control and the experimental sites to assess the polymers' efficacy in preventing dorsal epidural fibrosis.


RESULTS
The use of the polymers caused no adverse effects. Compared to the control sites, both polymers in either gel or membrane form significantly reduced the formation of epidural fibrosis and its area of contact with the dura postlaminectomy. However, no significant difference in efficacy was detected between either the polymers or their respective forms in preventing epidural fibrosis.


CONCLUSIONS
The selected compositions of biosynthetic, bioelastic polymers were safe and effective in the limiting the direct contact and consequent tethering of the underlying neural elements by the postlaminectomy epidural fibrosis in rabbits.
Alkalay
Ron N
RN
Harvard Medical School, Orthopaedic Biomechanics Laboratory, Boston, Massachusetts, USA.
Kim
David H
DH
Urry
Dan W
DW
Xu
Jie
J
Parker
Timothy M
TM
Glazer
Paul A
PA
D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000494:pharmacology*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004548:Elasticity; D004824:Epidural Space / Q000187:drug effects* / Q000473:pathology / Q000601:surgery; D005260:Female; D005355:Fibrosis / Q000473:pathology / Q000517:prevention & control*; D007796:Laminectomy / Q000009:adverse effects*; D008161:Lumbosacral Region; D008422:Materials Testing; D009842:Oligopeptides / Q000494:pharmacology; D011108:Polymers / Q000009:adverse effects / Q000494:pharmacology*; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D011817:Rabbits; D012449:Safety; D013131:Spine / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
C116171:(GVGVP)251; D001672:Biocompatible Materials; D009842:Oligopeptides; D011108:Polymers