[Chemonucleolysis using chymopapain and collagenase. 3-year results of a prospective randomized study]

100 patients were prospectively and randomized treated by chemonucleolysis either by collagenase (n = 50/400 ABC-U/disc) or by chymopapain (n = 50/4000 I.U.). The success rate after 1 year was 70% for collagenase and 78% after chymopapain, and 72%/80% after 3 years, respectively. Successful results increased significantly during the first year after treatment and remained stable after that point. After chymopapain, one case of successfully treated anaphylaxis (2%) occurred. After collagenase, 3 cases of secondary sequestrations were observed in cases with primarily closed discograms with intact dorsal longitudinal ligament.