title: Chemonucleolysis in lumbar disc herniation: a meta-analysis.
abstract: OBJECTIVE
  To carry out a systematic review and meta-analysis of the efficacy of chemonucleolysis in the treatment of lumbar disc herniation.
  
  
  METHODS
  Clinical trials were selected from 3 electronic databases (The Cochrane Controlled Trials Register, MEDLINE, and EMBASE). Data were analyzed with the software STATA, using the meta command.
  
  
  RESULTS
  Twenty-two clinical trials were eligible. For chemonucleolysis versus placebo, the summary risk ratio estimate for pain relief as outcome was 1.51 (95% CI: 1.27-1.80). The summary estimate was 1.07 (95% CI: 0.95-1.20) for the comparison between chymopapain and collagenase. Regarding chemonucleolysis with chymopapain versus surgery, the fixed-effect summary estimate of effect for pain relief was 0.93 (95% CI: 0.88-0.98) with surgery as the reference group. In this case, heterogeneity was statistically significant.
  
  
  CONCLUSIONS
  Chemonucleolysis with chymopapain was superior to placebo and was as effective as collagenase in the treatment of lumbar disc prolapse. Results for studies comparing chemonucleolysis with surgery were heterogeneous, making it difficult to interpret the summary measure of effect.
authors.affiliation: Department of Preventive Medicine, Medical School, São Paulo University, São Paulo, SP, Brazil.
authors.forename: José Mauro Cardoso
authors.initials: JM
authors.lastname: Couto
authors.forename: Euclides Ayres de
authors.initials: EA
authors.lastname: Castilho
authors.forename: Paulo Rossi
authors.initials: PR
authors.lastname: Menezes
mesh_terms: D002917:Chymopapain / Q000627:therapeutic use*; D017364:Collagenases / Q000627:therapeutic use*; D018849:Controlled Clinical Trials as Topic / Q000592:standards; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D006801:Humans; D007404:Intervertebral Disc Chemolysis / Q000592:standards*; D007405:Intervertebral Disc Displacement / Q000188:drug therapy*; D010919:Placebos / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic
chemical_list: D010919:Placebos; D002917:Chymopapain; D017364:Collagenases