Nicardipine Prolonged-release Implants - A Potential Tool for the Prevention of Cerebral Vasospasm?

Abstract

Despite considerable effort, no effective prophylactic treatment for cerebral vasospasm after subarachnoid haemorrhage (SAH) has been identified thus far. Treatment approaches have included the application of intravenous and therefore systemic vasodilatory drugs, which in turn have been found to be associated with significant side effects while at the same time exerting only limited efficacy. Consequently, a more local application, namely the intrathecal delivery of nicardipine prolonged-release implants (NPRI) has been developed. After surgical clipping of the causative aneurysm, these implants may be positioned adjacent to the proximal vasculature most at risk for developing delayed vasospasm. Several studies were able to show a dramatic reduction in both the incidence and severity of angiographic vasospasm, which in turn reduces the development of cerebral infarction and delayed ischaemic neurological deficits. While efficacy appears to be dose dependent, a reduction of angiographic vasospasm incidence from 70 % to less than 10 % has been observed, paralleled by an improvement of functional outcome. However, when applied intraventricularly after coiling of the offending aneurysm, effects were less pronounced. At this time, NPRIs seem to represent a very promising treatment option for the prevention of cerebral vasospasm after SAH, and larger studies will be needed to further supplement previous findings.