Historical perspective of carotid artery stenting in Japan: Analysis of 8,092 cases in the Japanese CAS survey

Background and purpose We conducted a large retrospective survey of the clinical results of carotid artery stenting (CAS) for about 10 years performed by neurointerventionists at 43 Japanese institutions. Hence, the historical perspective of CAS in Japan was demonstrated. Methods Cases were stratified into three separate periods based on the approval status of devices: the first period, in which off-label CAS was performed using balloon protection; the second period, using a limited number of approved devices under filter protection; the third period, using appropriate protection selected from several different options based on the preoperative evaluation (tailored CAS). Clinical results were retrospectively evaluated. Then 30-day results of each period were examined. The major adverse event (MAE) was defined as stroke, myocardial infarction or death. Results Between January 2001 and December 2010, a total of 8,092 cases were registered, including 4,072, 1,526 and 2,494 in the first, second and third period, respectively. In the first period, 92 % of CAS was performed under balloon protection. In contrast, 91 % was done under filter protection in the second period. In the third period, various protection methods were used, including balloon (31 %), filter (50 %) and proximal protection (18 %). The rate of MAE at 30 days was 6.1 %, 10.2 % and 3.5 % in the first, second and third periods, respectively, and 6.3 % in all periods combined. The rate of MAE in the third period was significantly lower than that in the first and second periods. Conclusions The historical paradigm of CAS in Japan was demonstrated. Due to the improvement of devices, increasing experience and appropriate selection of protection, CAS is continuing to evolve into a safer and more efficacious method of stroke prevention.