PURPOSE: To review the following aspects of surgical @entity23 ( @entity23 ) in @entity302 : rationale, methodological issues, and state of the art. METHODS: An overview of the literature and author's experience with methodological issues in surgical @entity23 , contrasting them with those encountered in medical trials; a general comparison of @entity23 and non- @entity23 (observational studies); and a literature search for and review of existing surgical @entity23 in @entity302 . RESULTS: Nonrandomized (observational) studies provide useful but potentially biased information about the effect of interventions. Because of their ability to deal with bias, @entity23 are the optimum vehicle to obtain a true estimate of the effect of interventions, including surgery. Only seven surgical @entity23 , encompassing 535 @entity1 , have been performed in @entity302 , with variable adhesion to standard methodology for conducting @entity23 . The major issues facing researchers undertaking surgical @entity23 in @entity302 include timing of the study in relation to adoption of the intervention as standard practice, acceptance of randomization to an invasive procedure, timing of randomization in relation to the actual intervention, standardization of the surgical procedure, blinding, and @entity1 recruitment. CONCLUSIONS: @entity23 are the gold standard for evaluating surgical treatments. Despite the large number and types of surgical interventions used to treat @entity302 , only a handful has been subjected to the scientific rigour of @entity23 . The challenges faced by researchers undertaking surgical @entity23 in @entity302 are substantial but not insurmountable. Possible avenues to address these methodological hurdles are suggested.

Randomized controlled trials of XXXX surgery.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity23 :: ('MESH:D007174', 'Disease') :: ['randomized controlled trials', 'RCTs'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epilepsy']
@entity302 :: (MESH:D004827,Disease) :: ['epilepsy']
