Condition category
Circulatory System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Ischaemic strokes occur when a blood clot blocks the flow of blood to the brain. Intra-arterial thrombolysis and mechanical thrombectomy is a new and promising treatment for patients with acute ischemic stroke. This treatment involves going into the brain arteries with a very small tube (catheter) to deliver treatment at the site of the blocked blood vessel that caused the stroke, reopening the blocked vessels and removing the clot. This study will investigate the effectiveness and safety of this treatment.

Who can participate?
Patients with acute ischemic stroke who admitted to the ER of one of the participating medical centers within 6 hours from onset of symptoms.

What does the study involve?
Participants are randomly allocated to receive either standard treatment for acute ischemic stroke or intra-arterial treatment as described above. Participants then undergo additional MRI or CT scans to check whether the blocked vessel has been reopened. After 1 week, a CT scan is carried out to assess the extent of the stroke. Blood is drawn at this time to look for blood clotting abnormalities. After 3 months, participants are approached by telephone to check on their general condition.

What are the possible benefits and risks of participating?
Those who participate in the study will benefit from high level stroke assessment by experienced stroke neurologists. As the effectiveness of the treatment is not yet proven, the opportunity to receive this treatment cannot be called a benefit. The treatment is probably associated with an increased risk of bleeding inside the skull and at the site of the cather insertion in the groin. Early studies so far suggest that the risks of the treatment are in balance with the expected benefit.

Where is the study run from?
In 14 large hospitals in the Netherlands, listed on the trial website:

When is the study starting and how long is it expected to run for?
December 2010 to January 2015

Who is funding the study?
The project is funded by the Dutch Heart Foundation, and by several companies, all of whom are listed on the trial website:

Who is the main contact?
Prof. Diederik Dippel and Prof. Charles Majoie

Trial website

Contact information



Primary contact

Prof Diederik Dippel


Contact details

Erasmus MC University Medical Center Rotterdam
's-Gravendijkwal 230
PO Box 2040
+31 (0)10 70 43979

Additional identifiers

EudraCT number number

Protocol/serial number

NTR1804 / NL 30557.078.10 v02

Study information

Scientific title

Multicenter Randomized CLinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands



Study hypothesis

The primary objective of this study is to estimate the effect of endovascular treatment on overall functional outcome after acute ischemic stroke of less than six hour duration, in patients with a symptomatic intracranial anterior circulation occlusion.

Ethics approval

Medical Ethics Committee and Resarch Board of Erasmus MC University Medical Center

Study design

Multicenter randomized open-label treatment and blinded endpoint evaluation (PROBE design)

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Patient information sheet can be found at: (Dutch)


Acute ischemic stroke, caused by intracranial proximal arterial occlusion (anterior circulation)


Intervention arms consists of endovascular treatment by means of microcatheter guided local application of recombinant tissue plasminogen activator (rt-PA) or urokinase, and/or mechanical thrombectomy, by means of a retraction device, aspiration device, or retrievable stent.

The control arm consists of regular treatment according to current national clinical guidelines.

Intervention type



Drug names

Primary outcome measure

Score on the modified Rankin scale at 3 months

Secondary outcome measures

Imaging parameters:
1. Vessel recanalization at 24 hours after treatment, assessed by CTA or MRA. The criteria for recanalization on CTA or MRA are based on a simplified TICI score (Table 5b),45 and the clot burden score, proposed by Puetz et al (Table 5c)46.
2. Infarct size assessed by CT on day 5-7, using standard methods, including manual tracing of the infarct perimeter and semiautomated pixel thresholding.47, 48 Infarct size at day 5-7 will be compared with plain CT and perfusion CT results (if available) at baseline.
3. CTA or MRA at 24 hours will be compared with baseline vessel imaging data, to estimate the recanalization rate. Perfusion CT at baseline is optional, but available at most centers.

Clinical parameters:
1. NIHSS, including NIH supplemental motor score, 50 at 24 hours
2. NIHSS at 1 week or at discharge.

Functional outcome:
1. Score on the EQ5D at 90 days
2. Barthel index at 90 days

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. A clinical diagnosis of acute stroke, with a deficit on the National Institutes of Health (NIH) stroke scale of 2 points or more
2. Computerised tomography (CT) or magnetic resonance imaging (MRI) scan ruling out intracranial hemorrhage
3. Intracranial arterial occlusion of the distal intracranial carotid artery or middle (M1/M2) or anterior (A1/A2) cerebral artery, demonstrated with Computed Tomography Angiography (CTA), magnetic resonance angiography (MRA), Digital subtraction angiography (DSA) or transcranial Doppler/duplex (TCD)
4. The possibility to start treatment within 6 hours from onset
5. Informed consent given
6. Age 18 or over

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Arterial blood pressure > 185/110 mmHg
2. Blood glucose < 2.7 or > 22.2 mmol/L
3. Intravenous treatment with thrombolytic therapy in a dose exceeding 0.9 mg/kg alteplase or 90 mg
4. Intravenous treatment with thrombolytic therapy despite contra-indications, i.e. major surgery, gastrointestinal bleeding or urinary tract bleeding within the previous 2 weeks, or arterial puncture at a non-compressible site within the previous 7 days

For Intended mechanical thrombectomy:
Laboratory evidence of coagulation abnormalities, i.e. platelet count <40 x 109/L, activated partial thromboplastin time (APTT)>50 sec or International Normalised Ratio (INR) >3.0.

For intended intra-arterial thrombolysis:
1. Cerebral infarction in the distribution of the relevant occluded artery in the previous 6 weeks
2. History of intracerebral hemorrhage
3. Severe head injury (contusion) in the previous 4 weeks
4. Clinical or laboratory evidence of coagulation abnormalities, i.e. platelet count <90 x 109/L, APTT>50 sec or INR >1.7

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Erasmus MC University Medical Center Rotterdam

Sponsor information


Dutch Heart Foundation (Netherlands)

Sponsor details

Prinses Catharina Amaliastraat 10
The Hague
2496 XD
+31 (0)70 31 55555

Sponsor type




Funder type


Funder name

Dutch Heart Foundation (Nederlandse Hartstichting) (Netherlands) ref: 2008T030

Alternative name(s)

Heart Foundation

Funding Body Type

private sector organisation

Funding Body Subtype

Trusts, charities, foundations (both public and private)



Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2014 protocol in:
2. 2015 results in:
3. 2016 results in:
4. 2016 results in:
5. 2016 results in:
6. 2016 results in:
7. 2016 results in:
8. 2016 results in:
9. 2017 results in:
10. 2017 results in:
11. 2017 results in:
12. 2017 results in:
13. 2017 results in:
14. 2017 results in:
15. 2017 results in:
16. 2017 results in:
17. 2017 results in:
18. 2018 results in:
19. 2018 results in:
20. 2018 results in:
21. 2018 results in
22. 2019 post hoc analysis in: (added 12/12/2019)

Publication citations

  1. Protocol

    Fransen PS, Beumer D, Berkhemer OA, van den Berg LA, Lingsma H, van der Lugt A, van Zwam WH, van Oostenbrugge RJ, Roos YB, Majoie CB, Dippel DW, , MR CLEAN, a multicenter randomized clinical trial of endovascular treatment for acute ischemic stroke in the Netherlands: study protocol for a randomized controlled trial., Trials, 2014, 15, 343, doi: 10.1186/1745-6215-15-343.

  2. Results

    Berkhemer OA1, Fransen PS, Beumer D, van den Berg LA, Lingsma HF, Yoo AJ, Schonewille WJ, Vos JA, Nederkoorn PJ, Wermer MJ, van Walderveen MA, Staals J, Hofmeijer J, van Oostayen JA, Lycklama à Nijeholt GJ, Boiten J, Brouwer PA, Emmer BJ, de Bruijn SF, van Dijk LC, Kappelle LJ, Lo RH, van Dijk EJ, de Vries J, de Kort PL, van Rooij WJ, van den Berg JS, van Hasselt BA, Aerden LA, Dallinga RJ, Visser MC, Bot JC, Vroomen PC, Eshghi O, Schreuder TH, Heijboer RJ, Keizer K, Tielbeek AV, den Hertog HM, Gerrits DG, van den Berg-Vos RM, Karas GB, Steyerberg EW, Flach HZ, Marquering HA, Sprengers ME, Jenniskens SF, Beenen LF, van den Berg R, Koudstaal PJ, van Zwam WH, Roos YB, van der Lugt A, van Oostenbrugge RJ, Majoie CB, Dippel DW; MR CLEAN Investigators, A randomized trial of intraarterial treatment for acute ischemic stroke, N Engl J Med, 2015, 372, 1, 11-20, doi: 10.1056/NEJMoa1411587.

  3. Results

    Yoo AJ, Berkhemer OA, Fransen PS, van den Berg LA, Beumer D, Lingsma HF, Schonewille WJ, Sprengers ME, van den Berg R, van Walderveen MA, Beenen LF, Wermer MJ, Nijeholt GJ, Boiten J, Jenniskens SF, Bot JC, Boers AM, Marquering HA, Roos YB, van Oostenbrugge RJ, Dippel DW, van der Lugt A, van Zwam WH, Majoie CB; MR CLEAN investigators, Effect of baseline Alberta Stroke Program Early CT Score on safety and efficacy of intra-arterial treatment: a subgroup analysis of a randomised phase 3 trial (MR CLEAN), Lancet Neurol, 2016, 15, 7, 685-694, doi: 10.1016/S1474-4422(16)00124-1.

  4. Results

    Berkhemer OA, Jansen IG, Beumer D, Fransen PS, van den Berg LA, Yoo AJ, Lingsma HF, Sprengers ME, Jenniskens SF1, Lycklama À Nijeholt GJ1, van Walderveen MA1, van den Berg R1, Bot JC1, Beenen LF1, Boers AM1, Slump CH1, Roos YB1, van Oostenbrugge RJ, Dippel DW, van der Lugt A, van Zwam WH, Marquering HA, Majoie CB; MR CLEAN Investigators, Collateral Status on Baseline Computed Tomographic Angiography and Intra-Arterial Treatment Effect in Patients With Proximal Anterior Circulation Stroke, Stroke, 2016 , 47, 3, 768-776, doi: 10.1161/STROKEAHA.115.011788.

  5. Results

    Al-Ali F, Berkhemer OA, Yousman WP, Elias JJ, Bender EN, Lingsma HF, van der Lugt A, Dippel DW, Roos YB, van Oostenbrugge RJ, van Zwam W, Dillon WP, Majoie CB, The Capillary Index Score as a Marker of Viable Cerebral Tissue: Proof of Concept-The Capillary Index Score in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Trial, Stroke, 2016, pii: STROKEAHA.116.013513, doi: 10.1161/STROKEAHA.116.013513.

  6. Results

    Berkhemer OA, van den Berg LA, Fransen PS, Beumer D, Yoo AJ, Lingsma HF, Schonewille WJ, van den Berg R, Wermer MJ, Boiten J, Lycklama À Nijeholt GJ, Nederkoorn PJ, Hollmann MW, van Zwam WH, van der Lugt A, van Oostenbrugge RJ, Majoie CB, Dippel DW, Roos YB; MR CLEAN investigators, The effect of anesthetic management during intra-arterial therapy for acute stroke in MR CLEAN, Neurology, 2016 , 87, 7, 656-664, doi: 10.1212/WNL.0000000000002976.

Additional files

Editorial Notes

12/12/2019: Publication reference added. 21/12/2018: Publication reference added. 10/10/2018: Publication reference added. 31/01/2018: Publication reference added. 30/01/2018: Publication reference added. 20/10/2017: Publication reference added. 19/10/2017: Publication references added. 28/04/2017: Publication reference added. 25/04/2017: Publication reference added. 24/04/2017: Publication reference added. 10/04/2017: Publication reference added. 30/03/2017: Publication reference added. 08/09/2016: Publication reference added. 22/08/2016: Publication reference added. 08/08/2016: Publication reference added. 20/07/2016: Publication reference added. 16/06/2016: Publication reference added.