Brain blood flow changes after successful clot removal in acute ischemic stroke

Investigation of Brain Blood Flow Changes in Acute Ischemic Stroke Patients After Successful Endovascular Thrombectomy

Observational University of Zurich · NCT07534319

This study will use a special MRI blood-oxygenation breathing test to see if it can detect patients with acute ischemic stroke who do not improve after successful clot removal.

Quick facts

Study typeObservational
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Zurich Academic / other
Locations1 site (Zurich, Canton of Zurich)
Trial IDNCT07534319 on ClinicalTrials.gov

What this trial studies

This is an observational, longitudinal imaging study that uses blood oxygenation–level dependent cerebrovascular reactivity (BOLD-CVR) MRI with breathing maneuvers to track brain blood flow changes after endovascular thrombectomy. Adult patients with ICA, MCA, or tandem occlusions who achieve successful recanalization (mTICI ≥2b) will be enrolled and undergo serial BOLD-CVR scans during hospitalization and follow-up. No experimental treatments are given; imaging findings will be compared with clinical outcomes to identify patterns associated with reperfusion failure. The goal is to determine whether BOLD-CVR changes can serve as an imaging biomarker for clinically ineffective reperfusion.

Who should consider this trial

Good fit: Adults over 18 with acute ischemic stroke due to ICA or MCA (including tandem occlusion) who underwent endovascular thrombectomy with successful recanalization (mTICI ≥2b) and can undergo MRI and provide informed consent.

Not a fit: Patients with standard MRI contraindications, severe cardiopulmonary disease preventing the breathing maneuvers, those who refuse participation, or those without successful recanalization are unlikely to benefit from this imaging-focused study.

Why it matters

Potential benefit: If successful, this approach could help doctors identify reperfusion failure early after thrombectomy so patients can receive targeted care to reduce further brain injury.

How similar studies have performed: Prior animal and clinical work has shown BOLD-CVR can reflect cerebrovascular health, but applying BOLD-CVR specifically to detect reperfusion failure after thrombectomy is relatively novel with limited prior clinical evidence.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Male and female subjects \>18 years old.
* Acute ischemic stroke related to a new occlusion of the internal carotid artery, middle cerebral artery (M1- and/or M2-segment), or both.
* Eligibility and performance of endovascular thrombectomy.
* Achievement of successful recanalization, defined as mTICI score ≥2b
* Written informed consent of the patient or when the patient is not able to participate in the consenting procedure, the written authorization of a family member. Foreign speaking patients should be included by a person with sufficient German language proficiency to act as a translator.

Exclusion Criteria:

* Documented evidence or a confirmed willingness of the patient not to participate in any scientific study.
* Standard contraindications for MRI, such as pacemaker, metallic prothesis, glaucoma, metallic tattoo dyes, verbal confirmed pregnancy. Unwilling or unable to cooperate with breathing manoeuvres.
* Major cardiopulmonary diseases, such as severe uncontrolled asthma bronchiale, severe chronic obstructive lung disease (i.e., GOLD stage ≥III), diffuse interstitial lung disease, pulmonary embolism, acute/subacute myocardial infarction, or severe heart failure (i.e., NYHA class ≥III).
* Symptomatic increased intracranial pressure.
* Presence of intracranial haemorrhage type ≥2 according to the Heidelberg classification.
* New onset of seizure.

Where this trial is running

Zurich, Canton of Zurich

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Acute Cerebrovascular AccidentThrombectomyCerebral RevascularizationNo Reflow PhenomenonAcute Ischemic StrokeReperfusion FailureBOLD-CVRAdvanced Haemodynamic Imaging
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.