RELEVANCE OF EPIDUROGRAPHY AND EPIDURAL ADHESIOLYSIS IN CHRONIC FAILED BACK SURGERY PATIENTS

Objective: Pain treatment in the chronic failed back surgery patient r emains problematic. Defining the pathogenesis of the pain could be hel pful in treatment. The assumption that epidural fibrosis and adhesions might play an important role in the origin of the pain is verified. D esign: We investigated 34 patients in whom peridural fibrosis was susp ected. An epidural catheter was inserted via the sacral hiatus. Inject ions of contrast dye, local anesthetic, corticosteroid, and hypertonic NaCl 10% were carried out daily for 3 days. Spread of the contrast dy e in the epidural space was evaluated after 10 and 20 ml injection vol ume. Setting: Subjects were patients in a pain clinic of a university hospital in Belgium. Patients: Chronic pain patients with failed back surgery syndrome were examined. Nerve pathology was demonstrated and e pidural fibrosis suspected or proved with magnetic resonance imaging ( MRI) examination. Outcome Measures: Improvement in the contrast fillin g defects of the epidural space were noticed during treatment and corr elated with pain improvement. Results: Filling defects were noted in 3 0 of the 34 patients investigated. After the third day an objective im provement of contrast spread was documented in 14 patients. In seven p atients improvement in pain occurred for only a very limited period (1 month). Statistical analysis (chi square analysis) could not demonstr ate that improvement of contrast spread was correlated with better pai n behavior. In 16 patients no improvement in contrast spread could be visualized. Pain improvement occurred in only four patients and for a limited period of 1 month. Long-term results are even worse. Conclusio n: Epidurography might confirm epidural filling defects for contrast d ye in the patients with epidural fibrosis. A better contrast dye sprea d, assuming scar lysis, does not guarantee a sustained pain relief. A more direct visualization of the resulting functional changes after ad hesiolysis as with epiduroscopy might be useful.