Intra-arterial thrombolysis for vertebrobasilar circulation ischemia

Intra-arterial thrombolysis in acute ischemic stroke: a review of pharmacologic approaches

Ischemic stroke is a major public health problem worldwide. The potential to cure stroke patients with intravenous thrombolytic therapy has evolved to the use of intra-arterial thrombolytic agents. Fewer than 200 patients have been enrolled in randomized trials of intra-arterial therapy. In this article the authors have reviewed the literature listed in MEDLINE and EMBase, and searched relevant articles to examine the role of fibrinolytic agents in acute interventional stroke therapy. Only English language articles reporting five or more patients were included. Outcomes were defined at 90 days. Good outcome was defined on the modified Rankin Scale. Symtpomatic hemorrhage was defined as hemorrhage in the setting of clinical deterioration in the first 24 to 48 h. The search identified 57 studies of which 44 reported usable data. Only three randomized trials were reported. Of a total of 1140 patients, most (73%) were treated open-label with urokinase (Abbokinase, Abbott Laboratories). The best outcomes were reported in case series and slightly worse outcomes were reported in clinical trials. Overall, it was not possible to distinguish whether one agent was superior to the others. There is a paucity of published evidence on intra-arterial therapy for acute ischemic stroke. Alteplase (Activase, Genentech Inc.) is currently the drug of choice simply because it is available and it is the current intravenous standard. Further trials and developments are anticipated.

New treatments in acute ischemic stroke

Since the advent of intravenous thrombolytic therapy with recombinant tissue plasminogen activator (tPA) for acute ischemic stroke, there has been a marked change in our management approach to patients with acute ischemic stroke. Although the major part of our focus in treating patients with stroke remains prevention of complications post-stroke and reduction of stroke recurrence, there is a paradigm shift to immediate "clot" lysis. This concept is being actively promoted through certification of institutions as stroke centers in order to increase the number of patients with stroke treated in an ultra-rapid fashion. However, options for acute treatment remain limited. Other than aspirin, the only US Food and Drug Administration-approved agent for acute ischemic stroke is intravenous tPA. Some physicians treating patients with acute ischemic stroke still frequently use heparin and low-molecular-weight heparinoids, but there are no firm data to support routine use of this drug class. However, a number of new lytic agents and strategies are being pursued. Some of these treatments, such as intra-arterial chemical thrombolysis or mechanical intra-arterial thrombolysis, are available only at specialized stroke centers. In addition, new antithrombotic agents are being studied. Drugs that can rescue neurons from impending hypoxia-ischemia cell death represent the "holy grail" of acute stroke therapy. To date, these "neuroprotectant" strategies have been unsuccessful, although this concept remains under active investigation in animal and human trials.

Thrombolytic treatment of acute cerebral infarction

Stroke is a common cause of death and disability throughout the world. Acute neurologic deficits due to ischemic injury deserve rapid recognition and diagnosis in order to provide effective therapy. Intravenous tissue plasminogen activator (t-PA) provided to carefully selected patients that can be treated within 3 hours of stroke onset results in improved outcome in these patients. Intra-arterial administration of t-PA within a 6-hour window is performed at several academic centers in patients with middle cerebral and other intracranial artery occlusions based on results of one randomized clinical trial and numerous case reports. Although acute therapy of ischemic stroke has received much attention since the approval of intravenous t-PA, only a small percentage of individuals suffering a stroke actually receive t-PA. This article will review the optimal management of the acute stroke patient and discuss thrombolytic clinical trials that have been completed as well as those that are in progress.

Antithrombotic trials in acute ischaemic stroke: a selective review

Stroke is a common cause of morbidity and mortality throughout the US and the world. Given the highly disabling nature of this disease, it is important to provide acute therapy when indicated to improve individual outcomes. Recombinant tissue plasminogen activator (rt-PA) is, at present, the only approved drug for the treatment of acute strokes due to cerebral ischaemia. It can be given intravenously within a 3-h window of the onset of neurological deficits. Intra-arterial administration of rt-PA within a 6-h window is performed at several academic centres in patients with middle cerebral and other intracranial artery occlusions based on results of a randomised clinical trial. Other thrombolytic agents are being studied in randomised trials. Although acute therapy of ischaemic stroke has received much attention since the approval of rt-PA, only a small percentage of individuals actually receive rt-PA. This article will review the main thrombolytic agents and the trials performed thus far, as well as examine some important ongoing trials. How administration of acute thrombolytic therapy may evolve in the future will also be addressed.

Basilar artery thrombosis in a trauma patient. Case report and review of the literature

Thrombotic disease of the vertebrobasilar circulation is associated with a poor prognosis. It may occur in trauma patients, especially those with neck injuries and even several months after the initial insult. We report on the case of a young polytrauma patient, victim of a traffic accident, with associated cervical and thoracic spinal injuries resulting in paraplegia. Consciousness was not impaired initially, but during transfer to our hospital he became suddenly unconscious. An occluded basilar artery was found on angiography, but unfortunately we were unable to reopen the vessel with thrombolytic therapy. This case again proves that lesions of the vertebro-basilar system must always be suspected in neck injuries. Even after minor whiplash injuries, fatal basilar thrombosis may occur. A review of all reported cases of traumatic basilar artery thrombosis is given and the use of thrombolytic therapy is discussed.