Platelets can be considered as the "guardian of hemostasis" where their main function is to maintain vascular integrity. In pathological conditions, the hemostatic role of platelets may be hijacked to stimulate disease progression. In 1865, Armand Trousseau was a pioneer in establishing the platelet-cancer metastasis relationship, which he eventually termed as Trousseau's Syndrome to describe the deregulation of the hemostasis-associated pathways induced by cancer progression (Varki, Blood. 110(6):1723-9, 2007). Since these early studies, there has been an increase in experimental evidence not only to elucidate the role of platelets in cancer metastasis but also to create novel cancer therapies by targeting the platelet's impact in metastasis. In this chapter, we discuss the contribution of platelets in facilitating tumor cell transit from the primary tumor to distant metastatic sites as well as novel cancer therapies based on platelet interactions.

Antiplatelet agents used to treat neurovascular disease include aspirin; P2Y12 receptor antagonists clopidogrel, prasugrel, and ticagrelor; ADP antagonist ticlopidine; phosphodiesterase inhibitor dipyridamole; and glycoprotein IIb/IIIa inhibitors abciximab, eptifibatide, and tirofiban. Numerous studies have been performed evaluating their efficacy in stroke, extracranial carotid artery disease and dissection, intracranial atherosclerotic disease, and moyamoya disease. The rapid technological advancements in endovascular neurosurgical devices have also made antiplatelet therapy a necessary part of treating intracranial aneurysms. This article presents the relevant data supporting the use of antiplatelet agents in vascular neurosurgery and recommendations based on the described studies.

The Solitaire (Medtronic Inc, Mansfield, Massachusetts, USA) is a stentriever device for endovascular treatment of acute ischemic stroke. Temporary endovascular bypass and mechanical thrombectomy are well-described applications of this device. However, few reports of permanent stent placement have been published. We present a series of five cases in which the Solitaire stent was implanted to restore distal flow after failure of conventional mechanical thrombectomy. All patients presented with large vessel occlusions with thrombi that were resistant to retrieval or suction-aspiration. Immediately after implantation the patients were given a loading dose of abciximab and then transitioned to dual antiplatelet therapy within 24 hours. Our series suggests that permanent deployment of the Solitaire may be considered as a bailout technique in the treatment of cerebral large vessel occlusion. Long-term antiplatelet therapy is required after deployment.