Temporal Profile of Recanalization After Intravenous Tissue Plasminogen Activator

Abstract

Background and Purpose-Intravenous thrombolysis in stroke achieves arterial recanalization in Ϸ50% of cases.Determining temporal profile of recanalization may address patient selection and potential benefits of further rescue reperfusion techniques. Methods-We studied 179 consecutive intravenous tissue plasminogen activator (t-PA)-treated patients with intracranial artery occlusion. Continuous transcranial Doppler assessed recanalization (none-partial-complete) at 60 minutes (early), 120 minutes (delayed) after t-PA bolus, and 6 hours (late) from symptom onset. Outcomes were determined: National Institutes of Health Stroke Scale (NIHSS; 48-hour NIHSS) and 3-month modified Rankin Scale (mRS). Results-On admission, 68% of patients presented proximal middle cerebral artery occlusion, median NIHSS 17.Early recanalization was complete for 30 patients (17%), partial for 50 (28%), and none for 99 (55%). Delayed recanalization was complete for 56 patients (31%), partial for 39 (22%), and none for 84 (47% T hrombolytic therapy with intravenous tissue plasminogen activator (t-PA) for acute ischemic stroke has shown to be effective by increasing and anticipating recanalization of the occluded brain vessels. 1,2 In the last years, different studies using multiple methods to assess cerebral flow described recanalization rates ranging from 30% to 60% in the first 6 to 24 hours after t-PA treatment. [2][3][4][5][6] However, the timing and temporal profile of recanalization in the very first hours after t-PA bolus remain uncertain. Continuous transcranial Doppler (TCD) monitoring at the bedside seems to be the best diagnostic tool to assess real-time recanalization. 7,8 The CLOTBUST study recently reported a 38% rate of complete recanalization at 2 hours after t-PA bolus in patients who received continuous ultrasound. 3 Nevertheless, detailed description of the temporal profile of partial versus complete recanalization during this time remains unknown. One hour after thrombolytic treatment initiation, information about the likelihood of complete recanalization during the following hours may help physicians identify those patients in whom intravenous t-PA will fail to induce early recanalization, making them eligible for rescue reperfusion therapies. We aim to study the probability and temporal profile of recana- Patients and MethodsFrom February 2002 to June 2005, all patients with an acute (Ͻ6 hours from symptom onset) stroke admitted to the emergency department of a university hospital were prospectively studied. A total of 928 patients were evaluated and underwent urgent extracranial and TCD ultrasound examination. Patients with an inadequate temporal bone window were excluded. A total of 179 patients had a TCD-documented intracranial occlusion and fulfilled established criteria for t-PA treatment (0.9 mg/kg). 1 None of these patients received rescue recanalization therapies. Clinical ProtocolA detailed history of vascular risk factors was obtained from each patient. To identify potential mechanism of cerebral infarction, ...

Intra-arterial Therapy for Acute Ischemic Stroke

“…Here again there is no agreed definition of failure, and when it is appropriate to treat patients who have received full-dose IV tPA with IAT. In a recent study using transcranial Doppler ultrasound in 179 patients treated with IV tPA, Ribo et al [54] documented that the majority of recanalization occurs within the first hour with few recanalization afterwards. These data suggest that if patients do not clinically improve and recanalize within 1 h, as assessed by noninvasive imaging (transcranial Doppler ultrasound, magnetic resonance angiography, or CT angiography), they may be candidates for IAT.…”

The management of acute ischemic stroke - a role for percutaneous intervention?

“…This score (0-42 with 0 being normal) is used to assess stroke severity and to help guide management decisions. Strokes can be divided into mild (NIHSS score <7), moderate (8)(9)(10)(11)(12)(13)(14)(15)(16), severe (17-24) and very severe (>24). Urgent brain imaging, either by CT scanning or MRI is mandatory.…”

“…In a study using transcranial Doppler 1 hour following iv tPA given within 3 hours of stroke onset, complete vessel patency is obtained in only 17% of cases, with partial fl ow in 28% and no recanalization in over half the cases. (9) The effi cacy of iv tPA also depends on the site of arterial occlusion. Patency rates following iv tPA for terminal internal carotid artery (ICA) occlusion is less than 10%.…”

Endovascular Mechanical Embolectomy for Acute Middle Cerebral Artery Occlusion Following Recent Cardiac Surgery

“…The current standard medical therapy for acute ischemic stroke is intravenous administration of recombinant tissue plasminogen activator (r-tPA) but its use is limited by narrow therapeutic time window of less than 4.5 hours [1]. It has been also associated with long recanalization times and poor revascularization rates in proximal large arterial occlusions and contraindicated for patients who had recent surgery, or stroke or head injury within the past three months [2,3].…”