Effect of the distal-balloon protection system on microembolization duringcarotid stenting

Background-The distal-balloon protection system is being evaluated for its efficacy in preventing embolic neurological events during carotid stenting (CAS). We sought to determine the effect of this system on the frequency of Doppler-detected microembolic signals (MES) during CAS. Methods and Results-Using transcranial Doppler, we compared the frequency o f MES during CAS in 2 groups: 39 patients without distal protection and 37 who used the distal-balloon protection system (GuardWire). There were no si gnificant differences in the clinical or angiographic characteristics betwe en the 2 groups. Three phases with increased MES counts were identified dur ing unprotected CAS, these were stent deployment, predilation, and postdila tion (75 +/- 57, 32 +/- 36, and 27 +/- 25 METS, respectively). The distal-b alloon protection significantly reduced the frequency of MES during CAS (ME S counts: 164 +/- 108 in the control versus 68 +/- 83 in the protection gro up; P=0.002), particularly during these 3 phases. MES in the protection gro up were detected predominantly during sheath placement, guidewire manipulat ion, and distal-balloon deflation. Conclusion-Three phases with increased MES counts were identified during un protected CAS (eg, stent deployment, predilation, and postdilation). The di stal-balloon protection system significantly reduced the frequency of MES d uring CAS, particularly during these 3 phases.