Cerebral protection vs no cerebral protection: timing of stroke with CAS

Since its development in the late 1980s the discussion of risk and benefit of carotid artery stenting (CAS) compared to carotid endarterectomy (CEA) is still ongoing. In this discussion the increasing technical inventions in CAS like PDs, different stent designs and materials and their effect upon the complication rates are playing increasingly important roles. We present a review of mono- or oligocentre studies with greater collectives, one review study and multi centre studies SPACE I, EVA-3S and preliminary data from the ICSS-trial, in which subgroups of patients were treated with or without protection devices. Despite the results of several retrospective studies mostly with historic comparator cohorts rather than concurrent the results of the most recent multi centre prospective randomized trials seem to show a benefit for unprotected stenting. The complication rates for protected vs. unprotected groups in SPACE I showed 8.3% vs. 6.5% and the pooled data from SPACE I and EVA-3S 8.1% vs. 7.3%. A subgroup analysis of SPACE I aiming at the impact of the stent design on peri-interventional complication rate shows that the pOE rate was significantly lower in patients treated with a closed cell stent (5.7%, 95% CI: 3.7-8.3%) than in those treated with an open cell stent (11.0%, 95% CI: 6.2-17.8%) (P=0.047). The most recent data from prospective multi centre trials support the presumption that PDs do not reduce, but may increase the periinterventional complication rate. Whereas many older single centre studies promoting PDs do show conceptual problems. The stent design appears to have a more important impact on the resulting complications in CAS, than the PDs.