Measuring Absolute Brain Flow and Brain Microcirculation Resistance by Continuous Thermodilution (RESISTANCE)

Measuring Absolute Brain Flow and Brain Microcirculation Resistance by Continuous Thermodilution: a Pilot Study - RESISTANCE

Worldwide, cerebrovascular accidents (also known as strokes) are the leading cause of acquired disability, the second-leading cause of dementia (after Alzheimer's disease) and the second-leading cause of death (but the leading cause of death among women). A mechanical thrombectomy (MT) allows the recanalization of the occluded cerebral artery during an acute ischemic stroke, by removing the blood clot with a mechanical device inserted endovascularly under image guidance. MTs are the optimal treatment for a large number of patients presenting an occlusion in an anterior artery (the internal carotid artery and the proximal segment of the middle cerebral artery). Reperfusion is considered satisfactory if the mTICI score at the end of the procedure is of mTICI 2c or mTICI 3. Despite these scores having been obtained by 71% of patients during the randomized trials, showing the superiority of MT over intravenous thrombolysis, only 27% of these patients were free of neurological deficits at 3 months . Therefore, there is a discrepancy between the high rate of macroscopic recanalization and clinical results. One hypothesis to explain this discrepancy is that despite high quality macroscopic recanalization, reperfusion of the cerebral microcirculation remains insufficient: macroscopic recanalization is not equivalent to microscopic reperfusion. This discrepancy also exists in cardiology: despite a high rate of coronary artery recanalization when patients with an ST- segment elevation myocardial infarction are in emergency care, half of these patients later exhibit coronary microvascular dysfunction. The absence of reperfusion is associated with an increased risk of cardiovascular death, recurring myocardial infarctions, cardiogenic shock and heart failure one year after the coronary recanalization for an ST-segment elevation myocardial infarction. It has been shown that continuous intracoronary thermodilution can be used to quantify coronary blood flow and the absolute value of microcirculatory resistance (in Wood units). There are not currently any tools that can quantify cerebral microcirculation immediately after an MT.

The aim of this study is to evaluate the feasibility and safety of using a pressure/temperature sensing guidewire to measure cerebral microcirculatory resistance using thermodilution in patients with a score of mTICI 2c or 3 after MT for the management of acute ischemic stroke in the anterior circulation.

Study Overview

• Status: Recruiting
• Conditions: Ischemic Stroke
• Intervention / Treatment: Device: Measuring Absolute Cerebral Flow and Microvascular Resistance by Thermodilution

• Study Type: Interventional
• Enrollment (Estimated): 15
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yves CHAU, MD; Phone Number: +33 4 92 03 35 90; Email: chau.hd@chu-nice.fr

Study Locations

• France
  • Alpes-maritimes
    • Nice, Alpes-maritimes, France, 06000
      • Recruiting
      • CHU de Nice
      • Contact: Yves CHAU, PH; Phone Number: +33 4 92 03 35 90; Email: chau.hd@chu-nice.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Men or women aged 18 to 80
• Social Security beneficiaries
• Obtained signed consent to participate in the study
• TICI 2c or TICI 3 score after mechanical thrombectomy
• Patients hospitalized for ischemic stroke due to middle cerebral artery thrombosis

Exclusion Criteria:

• Spasm of an artery without significant stenosis
• Vessel diameter less than 1 mm
• Severe visceral failure
• Local infection
• Minors
• Adults protected by law
• Patients deprived of their liberty
• Subjects who are uncooperative or unable to meet the requirements of the protocol
• Subjects participating in another clinical trial or in a period of exclusion from a previous clinical trial
• Pregnant women

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Device Feasibility
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: fully recanalization

Device: Measuring Absolute Cerebral Flow and Microvascular Resistance by Thermodilution; The measurements will be taken as follows: once satisfactory recanalization has been achieved (mTICI 2c or 3), the suction catheter will be placed at the origin of the M1 segment. Through this catheter, the pressure/temperature measurement microguide will be placed at the distal part of M1. The microcatheter will be placed on the microguide, with its tip positioned at the outlet of the aspiration catheter. A pressure sensor will be connected to the aspiration catheter. The microcatheter will be connected to the saline injector programmed to inject saline. The microguide is replaced in the microcatheter 165 seconds after the start of the injection. The trace of the variation in parameters will be recorded on the Coroventis station. A control injection will be performed after removal of the microcatheter and microguide from the suction catheter to ensure that there are no complications due to the measurement.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The primary objective is to assess the feasibility of measuring cerebral blood flow and cerebral microcirculatory resistance using thermodilution with the rayflow microcatheter and pressurewire guide.	The primary evaluation criterion is the proportion of patients for whom measurements of cerebral blood flow and cerebral microcirculatory resistance using thermodilution were possible.	Immediately after the measurement of cerebral blood flow and cerebral microcirculatory resistance using thermodilution done with the pressure temperature guidewire

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the safety of using thermodilution to measure cerebral blood flow and cerebral microcirculatory resistance	The safety of the procedure will be evaluated by counting the number of deaths, perforations and dissections associated with the use of the guidewire and/or the microcatheter and/or the injection of physiological serum.	Immediately after the measurement of cerebral blood flow and cerebral microcirculatory resistance using thermodilution done with the pressure temperature guidewire
To describe the clinical evolution of patients	Complications will be reported according to the recommendations of the Cardiovascular and Interventional Radiological Society of Europe	DAY 90
Determine the threshold value of the cerebral microcirculation resistance index that allows the definition of an optimal sensitivity/specificity pair for the prognosis of neurological progression (favorable or not).	The value of the cerebral microcirculation resistance index for distinguishing between patients who will have a favorable neurological outcome (mRS ≤ 2) and those who will have an unfavorable outcome (mRS > 2) will be calculated from the ROC curve generated by the data collected.	day 90
Measure the additional radiation dose received by patient	The increase in the additional dose will be compared to that corresponding to the patient's usual treatment.	day 1

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nice

Study record dates

Study Major Dates

• Study Start (Actual): April 7, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): November 1, 2027

Study Registration Dates

• First Submitted: February 6, 2026
• First Submitted That Met QC Criteria: April 27, 2026
• First Posted (Actual): May 5, 2026

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Stroke; Ischemic Stroke
• Other Study ID Numbers: 24-PP-08

Drug and device information, study documents

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