Reperfusion Injury After Endovascular Stroke Treatment (DYNASTROKE)

Hemodynamic Changes and Reperfusion Injury After Endovascular Stroke Treatment: Prospective Multicenter DYNASTROKE STUDY

Endovascular stroke treatment with mechanical thrombectomy (MT) has become the standard therapy for intracranial large vessel occlusion (LVO). The most serious MT-related complication is secondary intracranial hemorrhage (ICH) occurring in 20-25%. Post- recanalization hyperperfusion might be an important risk factor/mechanism of MT-related ICH. In pilot studies, bedside transcranial Duplex sonography (TCD) was identified as a promising screening tool for cerebral hyperperfusion predicting ICH - the hallmark feature of reperfusion injury.

There is an unmet need to identify risk factors for ICH after MT as it relates to poor prognosis, no proven treatment is available, and it delays/prohibits usage of anticoagulants/-thrombotics necessary for preventing recurrent stroke.

Main objectives:

To explore the range and clinical impact of hemodynamic changes after MT as detected on bedside TCD.

To assess whether patients with increased blood flow velocity in the recanalized middle cerebral artery (MCA) are at a higher risk to develop ICH / vasogenic brain edema (reperfusion injury) after MT.

To investigate if the underlying mechanism is cerebral hyperperfusion (confirmed by perfusion MRI).

To additionally study the role of blood biomarkers of blood-brain-barrier / endothelial dysfunction and neuroaxonal damage on reperfusion injury and short-term prognosis.

Approach / methods:

Prospective, longitudinal Austrian multicentre study conducted at three high-volume stroke centers (Graz, Innsbruck, Salzburg). The investigators will recruit consecutive stroke patients with anterior circulation L VO treated by MT. Immediately after MT, experienced sonographers will perform bedside TCD to determine MCA blood flow status, which will be repeated after 24-48h and on day 7. On day one after MT, brain MRI with perfusion serves to assess infarct size, secondary ICH, (vasogenic) brain edema and perfusion status. MRI will be centrally analyzed in the neuroimaging lab of Graz, blinded to clinical, laboratory and sonographic information. Blood samples for the analysis of biomarkers of endothelial (blood-brain barrier) dysfunction and neuroaxonal damage (neurofilament light) will be taken on day one and at three months post-MT. Neurological outcome will be rated according to the modified Rankin Scale at three months post-stroke.

Study Overview

• Status: Recruiting
• Conditions: Ischemic Stroke
• Intervention / Treatment: Diagnostic test: Transcranial Duplex Sonography; Diagnostic test: Brain MRI; Diagnostic test: Blood biomarkers

Detailed Description

Endovascular stroke treatment with mechanical thrombectomy (MT) has become the standard therapy for intracranial large vessel occlusion (LVO). The most serious MT-related complication is secondary intracranial hemorrhage (ICH) occurring in 20-25%. Post- recanalization hyperperfusion might be an important risk factor/mechanism of MT-related ICH. In pilot studies, bedside transcranial Duplex sonography (TCD) was identified as a promising screening tool for cerebral hyperperfusion predicting ICH - the hallmark feature of reperfusion injury.

There is an unmet need to identify risk factors for ICH after MT as it relates to poor prognosis, no proven treatment is available, and it delays/prohibits usage of anticoagulants/-thrombotics necessary for preventing recurrent stroke.

Main objectives:

To explore the range and clinical impact of hemodynamic changes after MT as detected on bedside TCD.

To assess whether patients with increased blood flow velocity in the recanalized middle cerebral artery (MCA) are at a higher risk to develop ICH / vasogenic brain edema (reperfusion injury) after MT.

To investigate if the underlying mechanism is cerebral hyperperfusion (confirmed by perfusion MRI).

To additionally study the role of blood biomarkers of blood-brain-barrier / endothelial dysfunction and neuroaxonal damage on reperfusion injury and short-term prognosis.

Approach / methods:

Prospective, longitudinal Austrian multicentre study conducted at three high-volume stroke centers (Graz, Innsbruck, Salzburg). The investigators will recruit consecutive stroke patients with anterior circulation L VO treated by MT. Immediately after MT, experienced sonographers will perform bedside TCD to determine MCA blood flow status, which will be repeated after 24-48h and on day 7. On day one after MT, brain MRI with perfusion serves to assess infarct size, secondary ICH, (vasogenic) brain edema and perfusion status. MRI will be centrally analyzed in the neuroimaging lab of Graz, blinded to clinical, laboratory and sonographic information. Blood samples for the analysis of biomarkers of endothelial (blood-brain barrier) dysfunction and neuroaxonal damage (neurofilament light) will be taken on day one and at three months post-MT. Neurological outcome will be rated according to the modified Rankin Scale at three months post-stroke.

Level of originality:

Human studies on reperfusion injury after MT are lacking. If the investigator's hypothesis would hold true and the investigators could show that cerebral hemodynamic changes after MT would increase the risk for post-interventional intracranial bleeding complications and poor outcome, the investigators would provide an easy-available, repeatable bedside screening and monitoring tool (TCD), which has the potential to guide individualized patient treatment in the early postinterventional period after MT.

The study was registered on Clinicaltrials.gov after start of recruitment.

• Study Type: Observational
• Enrollment (Estimated): 600

Contacts and Locations

• Study Contact: Name: Thomas Gattringer, MD, PhD; Phone Number: 004331638580231; Email: thomas.gattringer@medunigraz.at
• Study Contact Backup: Name: Markus Kneihsl, MD, PhD; Phone Number: 004331638582984; Email: markus.kneihsl@medunigraz.at

Study Locations

• Austria
  • Salzburg, Austria, 5020
    • Not yet recruiting
    • Paracelsus Medical University, Department of Neurology
    • Contact: Sebastian Mutzenbach, MD; Phone Number: 00435725556039; Email: j.mutzenbach@salk.at
  • Styria
    • Graz, Styria, Austria, 8036
      • Recruiting
      • Medical Univerity of Graz, Department of Neurology
      • Contact: Thomas Gattringer, MD, PhD; Phone Number: 004331638580231; Email: thomas.gattringer@medunigraz.at
      • Contact: Markus Kneihsl, MD, PhD; Phone Number: 004331638582984; Email: markus.kneihsl@medunigraz.at
  • Tyrol
    • Innsbruck, Tyrol, Austria, 6020
      • Not yet recruiting
      • Medical University of Innsbruck, Department of Neurology
      • Contact: Michael Knoflach, MD; Phone Number: +43-512-504-81697; Email: michael.knoflach@i-med.ac.at

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients with acute ischemic stroke due to large vessel occlusion of the anterior cerebral circulation (internal carotid artery, middle cerebral artery) receiving mechanical thrombectomy.

Description

Inclusion Criteria:

• stroke due to large vessel occlusion of the anterior cerebral circulation (internal carotid artery, middle cerebral artery) receiving mechanical thrombectomy.

Exclusion Criteria:

• basilar artery occlusion
• age below 18 years

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Observational Study (no different study arms); Prospective, longitudinal, multicenter, observational study to investigate hemodynamic changes (by TCD and perfusion MRI) and blood biomarkers as predictors of reperfusion injury / intracranial hemorrhage after stroke thrombectomy of the anterior cerebral circulation

Diagnostic test: Transcranial Duplex Sonography; Immediately after mechanical thrombectomy, patients will be investigated with bedside neurosonography (including TCD) at the stroke unit or neurointensive care unit. Apart from routine assessment of brain-supplying vessels, experienced sonographers will especially focus on intracranial blood flow velocities and determine the MCA mean blood flow velocity index (recanalized divided by contralateral artery). To assess potential dynamic blood flow changes, these investigations will be repeated at 24-48 hours after thrombectomy and at day 7 when we expect a (more) stable stroke phase. During these neurosonographic assessments, other important and potentially influential (hemodynamic) parameters such as blood pressure, heart rate and use of vasoactive medications will be documented. Assessment of intracranial blood flow will be standardized to dedicated measuring points.; Diagnostic test: Brain MRI; The investigators will use magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) routinely performed on day 1 after thrombectomy to assess (1) the size and location of acute ischemic damage including (vasogenic) cerebral edema formation, (2) hemorrhagic transformation, (3) concomitant chronic ischemic and hemorrhagic brain changes, and (4) patency of intracranial vessels. Contrast-enhanced or arterial spin labeling perfusion MRI will be used to (5) measure cerebral perfusion status. Findings from perfusion MRI will be correlated with blood flow information from TCD. MRI including MRA and perfusion sequences will be interpreted centrally in Graz as successfully demonstrated in previous large multicenter stroke studies.; Diagnostic test: Blood biomarkers; Apart from the assessment of outcome-relevant routine blood parameters of inflammation, coagulation, glucose metabolism, renal and liver function, the investigators will also investigate novel biomarkers of interest that could be indicative of endothelial damage / blood brain barrier disruption. Candidate markers for this purpose are interleukins (i.e., interleukin-6) and matrix metalloproteinases (i.e., MMP-9). Furthermore, the investigators will also measure neurofilament light chain protein as a marker for neuro-axonal damage that has been shown to indicate cerebral tissue destruction including vascular brain lesions with a very high sensitivity. For analysis, peripheral blood will be taken by venipuncture on day one and at follow- up three months after MT. Serum will be immediately stored at -80°C according to international consensus guidelines. Markers will be centrally analyzed in the neurological laboratory of the Department of Neurology, Medical University of Graz.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of intracranial hemorrhage	Rate of intracranial hemorrhage (indicator of reperfusion injury) on neuroimaging at day one after mechanical thrombectomy.	Day one after mechanical thrombectomy
Rate of (vasogenic) brain edema	Rate of (vasogenic) brain edema (indicator of reperfusion injury) on neuroimaging at day one after mechanical thrombectomy.	Day one after mechanical thrombectomy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cerebral blood flow changes on TCD	The range of cerebral blood flow changes on TCD and its correlation with perfusion MRI.	Immediately, 24-48 hours and 7 days post-thrombectomy, and after 3 months poststroke
Change of symptomatic intracranial hemorrhage	Rate of symptomatic intracranial hemorrhage post-thrombectomy.	Immediately, 24-48 hours and 7 days post-thrombectomy.
Inhospital mortality	Early inhospital mortality	Median inhospital stay of 7 days
Change of functional neurological outcome	Functional neurological outcome (according to the modified Rankin Scale with score of 0-6; higher scores indicating more severe disability) including mortality at three months post-stroke.	Hospital discharge (median of 7 days) and after 3 months poststroke

Collaborators and Investigators

• Sponsor: Medical University of Graz
• Collaborators: Medical University Innsbruck; Paracelsus Medical University

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2021
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: February 15, 2022
• First Submitted That Met QC Criteria: February 28, 2022
• First Posted (Actual): March 10, 2022

Study Record Updates

• Last Update Posted (Actual): June 13, 2025
• Last Update Submitted That Met QC Criteria: June 10, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Reperfusion Injury; Perfusion MRI; Intracranial Hemorrhage; Mechanical Thrombectomy; Endovascular Stroke Treatment; Transcranial Duplex Sonography; Cerebral Hyperperfusion
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Postoperative Complications; Pathologic Processes; Ischemic Stroke; Stroke; Reperfusion Injury
• Other Study ID Numbers: EK 30-254 ex 17/18

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No