[Postoperative sciatica from epidural fibrosis and lumbar arachnoiditis. Results of 38 repeat operations].

Lumbar epiduro-arachnoiditis is a well-known complication of surgery of the intervertebral disc. The epidural fibrous scar is the normal outcome of inflammatory activity secondary to the mechanical tissue disturbance resulting from surgery. In certain individuals, perhaps genetically predisposed as excessive quantity of fibrous tissue is deposited in the epi and/or nitradural space. This abnormal situation, comparable to cheloid cutaneous scars, is perhaps at the origin of the clinical symptoms. The authors report the clinical and radiological signs observed in 38 patients having had at least one operation for discal hernia, and who underwent further operations in the aim of freeing the roots and the dural sack from fibrous compression. Results of excision of the epidural "cheloid" were good in 13 cases, and average in 8 others. There was a complete failure in 17 other patients. Three explanations were offered to explain the frequency of the failures: 1) formation of a new cheloid, 2) difficulty of neurolysis of the arachnoiditis, 3) possibility of intrinsic lesions of the nerve associated with the epiduro-arachnoiditis.