Failures, Mistakes and Shortcomings of My Stroke Trials

ical treatment. The role of carotid surgery in asymptomatic carotid stenosis was unclear. The prospective study by Hennerici et al. [3] indicated that the stroke risk was relatively small. A group of vascular surgeons, neurologists and clinical trial experts therefore applied for a grant from the German Ministry of Science and Technology to perform a randomized trial comparing carotid surgery with best medical treatment in patients with asymptomatic carotid stenosis. After the grant had been approved, we called a meeting with the surgical centers in Germany from whom we knew that they had enough expertise in carotid surgery. Unfortunately the participating vascular surgeons thought that withholding surgery from patients with severe carotid stenosis and patients with bilateral disease would be unethical. Therefore the trial only randomized patients with unilateral moderate carotid stenosis. In addition the trial was underpowered and predictably failed to show a difference between surgical and medical treatment [4] . The lessons to be learned are as follows: (1) A good study acronym (CASANOVA) does not replace a proper study design (2) Sometimes it is better not to start a trial than to accept compromises which decrease the likelihood of achieving positive results Introduction