Complete study protocol

NIHSS scale

Modified Rankin scale

Inclusion criteria

Exclusion criteria

Protocol summary


Endovascular thrombolysis, with or without mechanical clot removal (ET), may be beneficial for a subgroup of patients with cerebral venous sinus thrombosis (CVT), who have a poor prognosis despite treatment with heparin. Published experience with ET is promising, but only based on case series and not on controlled trials.


The main objective of the TO-ACT trial is to determine if ET improves the functional outcome of patients with a severe form of CVT

Study design

The TO-ACT trial will be designed as a multi-centre, prospective, randomized, open-label, blinded endpoint (PROBE) trial.

Study population

Patients are eligible if they have a radiologically proven CVT, a high probability of poor outcome (defined by presence of one or more of the following risk factors: mental status disorder, coma, intracranial hemorrhagic lesion or thrombosis of the deep cerebral venous system) and the responsible physician is uncertain if ET or standard anti-coagulant treatment is better.


Patients will be randomized to receive either ET or standard therapy (therapeutic doses of heparin). ET consists of local application of alteplase or urokinase within the thrombosed sinuses. Standard endovascular techniques to mechanically remove clot material, such as thrombosuction, are allowed, but not mandatory. Glasgow coma score, NIH stroke scale and relevant laboratory parameters will be assessed at baseline.


The primary endpoint is the modified Rankin scale (mRS) at 12 months. The most important secondary outcomes are the mRS, mortality and recanalization rate at 6 months. Major intra- and extracranial hemorrhagic complications within one week following the intervention are the principal safety outcome. Results will be analyzed according to the "intention-to-treat" principle. Assessment of study endpoints will be carried out according to standardized questionnaires by a blinded neurologist or research nurse who is not involved in the treatment of the patient.

Study size

To detect a 50% relative reduction in mRS≥2 (from 40 to 20%), 164 patients (82 in each treatment arm) have to be included (two-sided alpha, 80% power).

Patients currently included

0 6 7

Last patient included on 14/10/2016 at Academic Medical CenterThe Netherlands



Academic Medical Centre
Department of Neurology H2-218

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The Netherlands 

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