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Study to Evaluate Cerebral AneurysmFlow Results in Occlusion

Multicenter Observational Cohort Study to Evaluate Cerebral AneurysmFlow Results in Occlusion

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03663257
Acronym
CARO
Enrollment
132
Registered
2018-09-10
Start date
2018-10-04
Completion date
2023-11-27
Last updated
2025-09-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Intracranial Aneurysm

Keywords

Interventional Neurology, Aneurysm, Neurology, Radiology, AneurysmFlow

Brief summary

AneurysmFlow R1.0 is an approved (i.e. CE labeled, 510k, Health Canada), software tool intended to provide relevant information on the blood flow in a cerebral aneurysm and its parent artery based on angiography. It calculates the Mean Aneurysm Flow Amplitude (MAFA) ratio to measure the volumetric flow rate quotient before and after Flow Diverter Stent (FDS) implantation in the region of interest. The current study is a prospective, single arm, observational, multicenter cohort study to assess the prognostic value of the MAFA ratio for predicting full aneurysm occlusion 12 months after flow diverter placement.

Detailed description

AneurysmFlow R1.0 is an approved (CE labeled, cleared in US, Canada and Argentina), software tool intended to provide relevant information on the blood flow in a cerebral aneurysm and its parent artery based on angiography. It provides color coded and vector field representation of a digital subtraction angiography (DSA). It can quantify blood flow rates in the artery based on DSA and 3-D Rotational Angiogram (3DRA) data. It can visualize blood flow patterns in an aneurysm based on DSA data. Specifically, it calculates the Mean Aneurysm Flow Amplitude (MAFA) ratio to measure the volumetric flow rate quotient before and after Flow Diverter Stent (FDS) implantation in the region of interest. It is manufactured by Philips Medical Systems bv., a Philips Healthcare company. 120 subjects with unruptured, \>5mm saccular aneurysm(s) located in the anterior intracranial circulation and suitable for an endovascular treatment with a Flow Diverter Stent will be enrolled in the study. The enrollment period is expected to last for 1 year. Physician investigators participating in this study are expected to follow their normal clinical practice in enrolling, treating and following patients with intracranial aneurysms that are amenable to treatment with flow diverter stents. No additional procedures are required of patients in order to participate in this observational study. Pre-Screening Patients presenting with intracranial saccular aneurysm(s) will be evaluated by the neuro interventional team, in accordance with institutional practice, to establish an appropriate treatment plan based on the patient's medical condition and available diagnostic screening procedures prior to recruitment in the study. More than one aneurysm in a single patient may be treated, but only one target aneurysm treated with an FDS device will be considered as part of this study. If treatment of the aneurysm with the FDS is deemed appropriate, the institution's guidelines regarding their ethics committee and informed consent process will be followed. Screening After obtaining the consent form(s) approved by the local research ethics board (REB), the principal investigator will screen the potential investigation subjects for the CARO study. The principal investigator or his delegates on the study team will enter data in a pre-designed digital Case Report Form (e-CRF). This will include patient demographics, relevant past medical and surgical history, and specific target aneurysm data along with pre-procedural/screening imaging details. Only patients who meet all inclusion and none of the exclusion criteria will qualify for this study. The measurement and size of each aneurysm will be verified by the principal investigator. If the size of the aneurysm is acceptable, then it will be included in the study. It is recommended that this measurement should be done within 180 days before the procedure. Index Procedure and Discharge The investigator will proceed with standard of care procedures on the day of Index Procedure (i.e. FDS insertion) for the target aneurysm(s). Then, endovascular treatment procedure details should be provided for each eligible patient. Blood flow velocity will be calculated using the dedicated software AneurysmFlow (Philips Healthcare, Best, The Netherlands), which will be installed on standard of care imaging equipment. For this purpose, digital subtraction angiograms will be acquired during the procedure; just before and right after placement of the FDS. Calculation of blood flow velocity will be performed automatically on the AneurysmFlow software. There are no additional devices or medications required for the study. The AneurysmFlow software uses standard-of-care 2D DSA and 3D-RA image sequences to determine this flow information. All raw image sequences will be stored for future reference. This study will not make any recommendation on patient management or on treatment strategy. Also, this software will not disrupt standard-of-care workflow for the interventionalist. Follow-Ups (6 and 12 months) All registry patients treated with FDS are expected to follow their routine post treatment clinical visits, which will include a standard-of-care head imaging (e.g. Computed Tomography Angiography (CTA), Magnetic Resonance Angiography (MRA) and/or DSA) test to classify aneurysm occlusion (i.e. Raymond-Roy Occlusion Classification I) at 6 months (±49 days) and 12 months (±49 days). During the 6 and 12 month follow up visits, patient medical charts will be accessed to collect adverse events (if applicable) and document any post-treatment neurological deterioration (neurological assessment, modified Rankin Scale). De-identified data (i.e. clinical notes, imaging reports etc.) will be entered in the relevant e-CRF sections. All (serious) adverse events (i.e. re-operations, ruptures and deaths) whether or not related to the investigational device will be collected and reported conform local rules and regulations. The total duration of the study is expected to take approximately 2.5 years. Patient enrollment will take place between September 2018 and September 2019. Each subject will be in the study for 1 year (follow-up).

Interventions

DEVICEAneurysmFlow

AneurysmFlow R1.0 is an approved (CE labeled, cleared in US, Canada and Argentina), software tool intended to provide relevant information on the blood flow in a cerebral aneurysm and its parent artery based on angiography. It provides color coded and vector field representation of a digital subtraction angiography (DSA). It can quantify blood flow rates in the artery based on DSA and 3-D Rotational Angiogram (3DRA) data. It can visualize blood flow patterns in an aneurysm based on DSA data. Specifically, it calculates the Mean Aneurysm Flow Amplitude (MAFA) ratio to measure the volumetric flow rate quotient before and after Flow Diverter Stent (FDS) implantation in the region of interest. It is manufactured by Philips Medical Systems B.V., a Philips Healthcare company.

Sponsors

Philips Clinical & Medical Affairs Global
Lead SponsorINDUSTRY

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Subject with unruptured, ≥5mm saccular aneurysm(s) located in the anterior intracranial circulation and suitable for an endovascular treatment with a Flow Diverter Stent * Subject is 18 years of age or older, or of legal age to give informed consent per state or national law. * Subject is available for clinical follow-ups.

Exclusion criteria

* Non-saccular brain aneurysm(s) (i.e. dissecting, fusiform, atherosclerotic, mycotic, bifurcational). Prior aneurysm treatment with either endovascular (stenting, coiling) or surgical (clipping) techniques. * Endovascular treatment assisted with coils or intracranial stents * Significant or severe allergy to intra-arterial contrast medium uncontrolled by pre-procedure medications. * Severe kidney disease (Glomerular Filtration Rate \< 60). * Subjects not willing (or able) to attend post FDS insertion standard-of-care follow up clinic visits requiring DSA, head MRI or CTA imaging. * Subject participates in a potentially confounding drug or device trial during the course of the study. * Subject meets an

Design outcomes

Primary

MeasureTime frameDescription
Prognostic Value of the MAFA (Mean Aneurysm Flow Amplitude) Ratio With Respect to Full Aneurysm Occlusion Within 12 Months12 monthsTo assess the prognostic value (i.e. c-statistic including confidence intervals) of the MAFA ratio with respect to full aneurysm occlusion (i.e. using the Raymond-Roy Occlusion Classification I on standard-of-care head imaging) 12 months after Flow Diverter Stent placement. The objective was evaluated using logistic regression analysis to evaluate the univariate predictive association between the index test (i.e., the MAFA ratio) and complete aneurysm occlusion (i.e., complete occlusion yes/no) at 12 months. The primary endpoint was presented using a Receiver Operating Characteristic (ROC) curve including the c-statistic (also known as the Area Under the Curve (AUC) of the ROC curve) and confidence intervals.

Secondary

MeasureTime frameDescription
Serious Adverse Events12 monthsTo register serious adverse events (i.e. re-operations, ruptures and deaths).
Prognostic Value of the MAFA Ratio With Respect to Full Aneurysm Occlusion Within 6 Months6 monthsTo assess the prognostic value (i.e. c-statistic including confidence intervals) of the MAFA ratio with respect to full aneurysm occlusion (i.e. using the Raymond-Roy Occlusion Classification I on standard-of-care head imaging) 6 months after Flow Diverter Stent placement. The objective was evaluated using logistic regression analysis to evaluate the univariate predictive association between the index test (i.e., the MAFA ratio) and complete aneurysm occlusion (i.e., complete occlusion yes/no) at 12 months. The endpoint was presented using a Receiver Operating Characteristic (ROC) curve including the c-statistic (also known as the Area Under the Curve (AUC) of the ROC curve) and confidence intervals.
Optimal MAFA Threshold12 monthsTo determine the optimal threshold for the MAFA ratio (to predict full aneurysm occlusion within 12 months), ROC analysis will be performed in combination with net-benefit analysis. Net benefit incorporates estimates of prevalence and misclassification costs, and it is clinically interpretable since it reflects changes in correct and incorrect diagnoses when a new diagnostic test is introduced. The optimal MAFA ratio threshold for clinical decision making is defined as the MAFA ratio where the net benefit is maximized. MAFA (Mean Aneurysm Flow Amplitude) = (mean aneurysm flow post / mean aneurysm flow pre) \* (mean arterial flow pre / mean arterial flow post)

Countries

Argentina, Canada, United States

Participant flow

Participants by arm

ArmCount
AneurysmFlow Observational Cohort
Subjects with unruptured, \>5mm saccular aneurysm(s) located in the anterior intracranial circulation and suitable for an endovascular treatment with a Flow Diverter Stent enrolled at the centers participating in this CARO study. AneurysmFlow: AneurysmFlow R1.0 is an approved (CE labeled, cleared in US, Canada and Argentina), software tool intended to provide relevant information on the blood flow in a cerebral aneurysm and its parent artery based on angiography. It provides color coded and vector field representation of a digital subtraction angiography (DSA). It can quantify blood flow rates in the artery based on DSA and 3-D Rotational Angiogram (3DRA) data. It can visualize blood flow patterns in an aneurysm based on DSA data. Specifically, it calculates the Mean Aneurysm Flow Amplitude (MAFA) ratio to measure the volumetric flow rate quotient before and after Flow Diverter Stent (FDS) implantation in the region of interest. It is manufactured by Philips Medical Systems B.V., a Philips Healthcare company.
106
Total106

Baseline characteristics

CharacteristicAneurysmFlow Observational Cohort
Age, Continuous57.0 years
STANDARD_DEVIATION 13
Aneurysm location in Internal Carotid Artery segment
C1 (Cervical Segment)
1 Participants
Aneurysm location in Internal Carotid Artery segment
C2 (Petrous Segment)
1 Participants
Aneurysm location in Internal Carotid Artery segment
C3 (Lacerum Segment)
0 Participants
Aneurysm location in Internal Carotid Artery segment
C4 (Cavernous Segment)
16 Participants
Aneurysm location in Internal Carotid Artery segment
C5 (Clinoid Segment)
14 Participants
Aneurysm location in Internal Carotid Artery segment
C6 (Ophthalmic Segment)
52 Participants
Aneurysm location in Internal Carotid Artery segment
C7 (Communicating Segment)
19 Participants
Aneurysm location in Internal Carotid Artery segment
Unknown
3 Participants
Aneurysm measurements
Aneurysm maximum height
6.3 mm
STANDARD_DEVIATION 4.3
Aneurysm measurements
Aneurysm neck diameter
4.6 mm
STANDARD_DEVIATION 2.2
Medical history
Hyperlipidemia
18 participants
Medical history
Hypertension
44 participants
Medical history
Migraines
22 participants
Race/Ethnicity, Customized
Self-reported Race
American Indian or Alaska Native
0 Participants
Race/Ethnicity, Customized
Self-reported Race
Asian
2 Participants
Race/Ethnicity, Customized
Self-reported Race
Black or African American
8 Participants
Race/Ethnicity, Customized
Self-reported Race
Native Hawaiian or Other Pacific Islander
0 Participants
Race/Ethnicity, Customized
Self-reported Race
Unknown
3 Participants
Race/Ethnicity, Customized
Self-reported Race
White
93 Participants
Region of Enrollment
Argentina
55 participants
Region of Enrollment
Canada
14 participants
Region of Enrollment
United States
37 participants
Sex: Female, Male
Female
96 Participants
Sex: Female, Male
Male
10 Participants
Smoking history
Current smoker, greater than or equal to one pack per day
3 Participants
Smoking history
Current smoker, less than one pack per day
11 Participants
Smoking history
Never smoked or has not smoked within the last 10 years
33 Participants
Smoking history
Not a current smoker, but has smoked within the past 10 years
17 Participants
Smoking history
Unknown
42 Participants
Type of presentation
Incidental
80 Participants
Type of presentation
Symptomatic
26 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
1 / 132
other
Total, other adverse events
4 / 132
serious
Total, serious adverse events
4 / 132

Outcome results

Primary

Prognostic Value of the MAFA (Mean Aneurysm Flow Amplitude) Ratio With Respect to Full Aneurysm Occlusion Within 12 Months

To assess the prognostic value (i.e. c-statistic including confidence intervals) of the MAFA ratio with respect to full aneurysm occlusion (i.e. using the Raymond-Roy Occlusion Classification I on standard-of-care head imaging) 12 months after Flow Diverter Stent placement. The objective was evaluated using logistic regression analysis to evaluate the univariate predictive association between the index test (i.e., the MAFA ratio) and complete aneurysm occlusion (i.e., complete occlusion yes/no) at 12 months. The primary endpoint was presented using a Receiver Operating Characteristic (ROC) curve including the c-statistic (also known as the Area Under the Curve (AUC) of the ROC curve) and confidence intervals.

Time frame: 12 months

Population: The Analysis Population is defined as all enrolled subjects that met the eligibility criteria, have the AneurysmFlow measurements recorded pre and post Flow Diverter Stent placement, and have the aneurysm occlusion state (Scale of Roy) available for the 6 month and/or 12 month follow up visit.

ArmMeasureValue (NUMBER)
AneurysmFlow Observational CohortPrognostic Value of the MAFA (Mean Aneurysm Flow Amplitude) Ratio With Respect to Full Aneurysm Occlusion Within 12 Months0.540 probability
Secondary

Optimal MAFA Threshold

To determine the optimal threshold for the MAFA ratio (to predict full aneurysm occlusion within 12 months), ROC analysis will be performed in combination with net-benefit analysis. Net benefit incorporates estimates of prevalence and misclassification costs, and it is clinically interpretable since it reflects changes in correct and incorrect diagnoses when a new diagnostic test is introduced. The optimal MAFA ratio threshold for clinical decision making is defined as the MAFA ratio where the net benefit is maximized. MAFA (Mean Aneurysm Flow Amplitude) = (mean aneurysm flow post / mean aneurysm flow pre) \* (mean arterial flow pre / mean arterial flow post)

Time frame: 12 months

Population: The Analysis Population is defined as all enrolled subjects that met the eligibility criteria, have the AneurysmFlow measurements recorded pre and post Flow Diverter Stent (FDS) placement, and have the aneurysm occlusion state (Scale of Roy) available for the 6 month and/or 12 month follow up visit.

ArmMeasureValue (NUMBER)
AneurysmFlow Observational CohortOptimal MAFA ThresholdNA MAFA ratio
Secondary

Prognostic Value of the MAFA Ratio With Respect to Full Aneurysm Occlusion Within 6 Months

To assess the prognostic value (i.e. c-statistic including confidence intervals) of the MAFA ratio with respect to full aneurysm occlusion (i.e. using the Raymond-Roy Occlusion Classification I on standard-of-care head imaging) 6 months after Flow Diverter Stent placement. The objective was evaluated using logistic regression analysis to evaluate the univariate predictive association between the index test (i.e., the MAFA ratio) and complete aneurysm occlusion (i.e., complete occlusion yes/no) at 12 months. The endpoint was presented using a Receiver Operating Characteristic (ROC) curve including the c-statistic (also known as the Area Under the Curve (AUC) of the ROC curve) and confidence intervals.

Time frame: 6 months

Population: The Analysis Population is defined as all enrolled subjects that met the eligibility criteria, have the AneurysmFlow measurements recorded pre and post Flow Diverter Stent placement, and have the aneurysm occlusion state (Scale of Roy) available for the 6 month and/or 12 month follow up visit.

ArmMeasureValue (NUMBER)
AneurysmFlow Observational CohortPrognostic Value of the MAFA Ratio With Respect to Full Aneurysm Occlusion Within 6 Months0.568 probability
Secondary

Serious Adverse Events

To register serious adverse events (i.e. re-operations, ruptures and deaths).

Time frame: 12 months

ArmMeasureValue (NUMBER)
AneurysmFlow Observational CohortSerious Adverse Events6 serious adverse events

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026