Sodium hyaluronate, 1.9%
solution, was evaluated for its ability to retard peridural
fibrosis after unilateral lumbar hemilaminotomy, anular fenestration, and nuclectomy in dogs. Three materials: fat grafts,
gelfoam, and
sodium hyaluronate, were compared with empty controls for their ability to inhibit peridural
fibrosis. Each dog served as his own internal control and the formation of
fibrosis was evaluated at 2, 4, 12, and 26 weeks.
Sodium hyaluronate was found to inhibit
fibrosis more than the other materials on both a macroscopic and microscopic level. The area of
fibrosis and tenacity of the adhesions on dissection were notably less in the
sodium hyaluronate group. Microscopically, the thickness of
collagen and number of fibroblasts were decreased with the use of 1.9%
sodium hyaluronate. The peridural
fibrosis occurred equally both anteriorly and posteriorly to the nerve roots and correlated with the area of surgical dissection. Fat grafts were not effective in preventing
fibrosis anteriorly, especially in the region of the exiting nerve roots.
Gelfoam did not inhibit but actually appeared to increase
fibrosis formation. Interposition materials currently used in humans to prevent
scar formation such as
gelfoam and fat grafts have only addressed the posterior
scar formation, which do little to alter the
fibrosis anteriorly. The adhesions between the nerve root and the anulus fibrosus bind the nerve root down anteriorly, making it more vulnerable to recurrent
disc herniation.
Sodium hyaluronate, 1.9%
solution, with its viscous semifluid properties, coats the nerve roots and dura anteriorly and posteriorly.(ABSTRACT TRUNCATED AT 250 WORDS)