Efficacy and safety of nicardipine prolonged-release implants for preventing vasospasm in humans

Background and Purpose-Despite extensive investigative efforts, there are few treatments that can prevent vasospasm after subarachnoid hemorrhage. This study was conducted to examine the efficacy and safety of nicardipine prolonged-release implants (NPRI) for humans, which have already been proven in dogs. Methods-Twenty consecutive subarachnoid hemorrhage patients with thick subarachnoid clot were treated with NPRI (a pellet of diameter 2 mm, length 10 mm, containing 4 mg of nicardipine) during surgery after clipping of their aneurysm. The number and location of pellets depended on the amount and site of subarachnoid clot on preoperative CT and on craniotomy. Results-Two to 10 pellets were implanted in the cistern of the internal carotid, middle cerebral, and/or anterior cerebral artery, where thick clots existed and therefore vasospasm related to delayed ischemic neurological deficits was highly likely. Delayed ischemic neurological deficits and cerebral infarctions were seen in I patient. Angiography performed on days 7 to 12 revealed no vasospasm in any arteries near which NPRI were placed. No complications were experienced. Conclusions-Vasospasm was completely prevented for the arteries in thick clot cisterns, when NPRI were placed adjacent to the arteries during surgery. This drug-delivery system offers a promising approach for preventing vasospasm.