| Producing quality randomized controlled trials in the field of surgery and, in particular, cardiac surgery can be a formidable task. Surgeons face difficulties not frequently encountered in non-surgical studies. Addressing the difficulties peculiar to this medical specialty may improve the quality of future surgical trials. Issues such as blinding, sample size, control groups and bias are but a few of the dilemmas that must be attended to in order to design a good quality surgical study. This thesis evaluates the quality of surgical studies available in the cardiac surgical literature, identifies obstacles encountered, and seeks to develop guidelines for future cardiac surgical protocols. Studies using aortic valve replacement procedures are the focus of the thesis. An extensive literature search on aortic valve replacement encompassing publications from 1986-2004 was used to evaluate the quality of surgical studies. A pool of 646 studies was narrowed down to 23 papers which were selected for detailed analysis. In the second part of the thesis, a list of obstacles to conducting surgical trials was constructed from the literature and the author's experience. A revised list of obstacles based on the experience from the systematic review was developed. This list was then applied to a year of publications of the Journal of Thoracic and Cardiovascular Surgery and the Annals of Thoracic Surgery . A final list was then developed consisting of obstacles encountered in conducting clinical trials in surgery. Finally, the U.K. Medical Research Council guidelines as adapted by the Canadian Institutes of Health Research were used in conjunction with the information procured in this study to generate guidelines for conducting surgical trials and applied in developing a specific protocol for comparing two bioprosthetic heart valves. |
