Topical use of colchicine to prevent spinal epidural fibrosis in rats.

OBJECTIVE

Epidural fibrosis after spinal surgery may be the cause in most cases of recurrent pain. Numerous pharmacological agents and anti-adhesive barriers have been used to prevent epidural fibrosis, but the success rates are variable. Colchicine is an historical drug extracted from the flowers of Colchium autumnale widely used in arthritic conditions in the past. Currently, it is used in acute gout attacks, familial mediterranean fever for its anti-inflammatory and antifibrotic effects. Also, colchicine is used locally in the cutaneous diseases (e.g. actinic keratoses, psoriasis) for its similar effects. In present study, we investigated the effect of topical colchicine on spinal epidural fibrosis in the rats.

METHODS

The rats were randomly divided to three groups of six animals each. Total L4-5 laminectomy was performed, and ligamentum flavum and epidural fat were removed gently. Meticulous hemostasis was achieved by using cotton pad when necessary, and no bone wax and cauterization were used. Dura was left clean with no hemorrhages. In treatment group cotton pads (5 × 5 mm) soaked with 0.005 mg/ml colchicine and applied on laminectomy sites for 10 minutes and removed, in sham group only saline irrigation was done. In control group no medication or irrigation was applied. The wound was closed in layers using the same material in each group. Four weeks later, the rats were killed, and the spinal column, including surrounding muscle tissue, was removed en bloc, decalcified, and fixed in formaldehyde. Epidural fibrosis was evaluated histologically.

RESULTS

In colchicine-treated group, epidural fibrosis was significantly reduced compared with control and sham groups.

CONCLUSIONS

Epidural fibrosis is a well-known complication following lumbar disc surgery. Topical application of colchicine is very effective in preventing epidural fibrosis.