Surgical procedures are complex interventions, whose characteristics pose serious challenges to developing high quality randomised controlled trials. As a result, regulators have not required such trials before permitting widespread use, in contrast to pharmaceuticals for which licensing systems require valid RCT evidence of safety and efficacy. Surgical innovations frequently gain acceptance based on evidence from biased observational studies.

The relative lack of regulatory pressure, together with the unique characteristics of surgical interventions, has resulted in persistent difficulties in obtaining high-quality evidence for surgical innovations. Assessment of new surgical interventions is complicated by a specific set of problems. These include the difficulty in defining surgical procedures precisely, iterative modification of procedures by surgeons during development, lack of agreed standard outcomes in surgery, operator learning curves, variable procedural quality as well as strong treatment preferences among patients and clinicians.

Recognition of these difficulties led to the development of the Idea, Development, Exploration, Assessment and Long-term follow-up (IDEAL) Framework and Recommendations, to establish a more scientifically rigorous and ethical evaluation pathway. (Hirst A, et al. No Surgical Innovation Without Evaluation: Evolution and Further Development of the IDEAL Framework and Recommendations. Ann Surg. 2019 Feb;269(2):211-220.)