Flow Diversion in Intracranial Aneurysm Treatment (FIAT)

A Randomized Trial Comparing Flow Diversion and Best-standard Treatment - the FIAT Trial

Flow diverters are a recent addition to the range of endovascular devices now available for the treatment of intracranial aneurysms. The FIAT trial aims at comparing flow diversion to best standard treatment in the context of a randomised controlled trial. Best standard treatment may include any of the following and will be left to the treating physician to decide : 1) conservative management; 2) coiling with or without high porosity stenting; 3) parent vessel occlusion with or without bypass; 4) surgical clipping. If the only treatment alternative is deemed to be flow diversion for compassionate use, then randomisation will not be carried out, but patient will enter a registry and her data recorded according to same schedule as randomised patients.

The primary hypothesis is that flow diversion can be performed with an "acceptable" immediate complication rate, defined as less than 15% morbidity and mortality, AND increase the number of patients experiencing successful therapy, defined as complete or near complete occlusion of the aneurysm from 75 to 90%, relative to best standard treatment.

Study Overview

• Status: Completed
• Conditions: Intracranial Aneurysm
• Intervention / Treatment: Procedure: flow diversion; Other: conservative management; Procedure: endovascular coiling; Procedure: balloon parent vessel occlusion; Procedure: surgical clipping

Detailed Description

Background:

Intracranial aneurysms, particularly large/giant, fusiform or recurrent aneurysms are increasingly treated with flow diverters (FDs), a recently introduced and approved neurovascular device. While some rare cases may not be treated any other way, in most patients a more conventional, conservative, or validated approach such as coiling, parent vessel occlusion, or surgical clipping exists. Early series and registries of the use of FDs in various types of aneurysms have reported treatment-related morbidity and mortality ranging from 0 to 4 and 8% respectively, most often from delayed haemorrhage. Hence, although there is growing enthusiasm to use these powerful new tools, complications are increasingly reported.

Rationale and Hypothesis:

There is an urgent need to offer the new tool afforded by FDs to patients currently presenting with a difficult aneurysm, in a context that can offer protection from over-optimistic perspectives, fashion, learning curves and marketing. Only a randomized clinical trial can offer such protection as well as provide an answer to the question of which treatment option leads to better patient outcomes. The primary hypothesis is that flow diversion can be performed with an "acceptable" immediate complication rate, defined as less than 15% morbidity and mortality (modified Rankin Score > 2 at 3 months), AND increase the number of patients experiencing successful therapy, defined as complete or near complete occlusion of the aneurysm from 75 to 90%.

Objectives:

Compare flow diversion (FD) to Best-Standard Treatment (BST) in the context of an RCT. BST may be any of the following: 1) conservative management; 2) coiling with or without high porosity stenting; 3) parent vessel occlusion with or without bypass; 4) surgical clipping; 5) enter a registry for FD, when the only treatment alternative is FD for compassionate use.

Methods:

Following randomization to FD or BST, patients will undergo the assigned intervention and be followed for 12 months. Clinical status will be recorded at discharge, at 1-3 months, and at 3-12 months. Angiographic evaluation will be recorded at 3-12 months. Adverse Events will be recorded immediately after the procedure and during the 12-month follow-up period. Patients in the FD registry will similarly be followed for 12 months. A total of 344 patients will be recruited in 20 centers worldwide. The trial is expected to last for 5 years.

Analysis:

Comparability between FD and BST groups will use descriptive statistics or frequency tables, independent ANOVAs or Mantel-Haentzel and chi-square tests. Comparison of primary outcome will use a z-test for independent proportions at 12 months. Safety data will be compared through independent t-tests or chi-square statistics. Logistic regression will be used to find variables capable of predicting success in both groups at 12 months.

• Study Type: Interventional
• Enrollment (Actual): 323
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada
      • University of Alberta Hospital
  • Ontario
    • Ottawa, Ontario, Canada
      • The Ottawa Hospital
  • Quebec
    • Montreal, Quebec, Canada, H2X 0C1
      • Centre Hospitalier de l'Université de Montréal - Hôpital Notre Dame

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Any patient with a "difficult" intracranial aneurysm in whom flow diversion is considered an appropriate if not the best but yet unproved therapeutic option by the participating clinician. Current indications may be (but not restricted to) symptomatic large or giant cavernous carotid, ophthalmic and vertebral aneurysms, fusiform intradural aneurysms, or recurring, persistent lesions after previous coiling. Aneurysm may be a recent rupture, although risks associated with antiplatelet regimens in this context should make this option rarely used

Exclusion Criteria:

• Severe allergy, intolerance or bleeding disorder that prohibit the use of ASA or clopidogrel.
• Absolute contraindication to endovascular treatment or anesthesia.
• Patients unable to give informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Registry for flow diversion; Flow diversion when randomization between flow diversion and best standard treatment is not possible and the only alternative is flow diversion for compassionate use. In this case there will be no random allocation but the patient will be entered into a registry	Procedure: flow diversion; endovascular treatment with flow diversion including standard management of thrombo-embolic risk
Active Comparator: flow diversion; Flow diverters are low porosity braided endovascular stent devices. They can be used with or without coiling.	Procedure: flow diversion; endovascular treatment with flow diversion including standard management of thrombo-embolic risk
Active Comparator: Best standard treatment; Best standard treatment can by any of the standard management options: coiling, stenting plus coiling, surgical clipping, parent vessel occlusion, observation	Other: conservative management; conservative management is watchful observation of the aneurysm until indication for intervention arises; Procedure: endovascular coiling; standard endovascular coiling of aneurysm with any type of already approved coil. High porosity stents may be used as an adjunct technique to coiling; Procedure: balloon parent vessel occlusion; sacrifice of parent artery of aneurysm by endovascular balloon occlusion with or without bypass; Procedure: surgical clipping; clipping of the aneurysm following invasive brain surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
rate of success of therapy	Rate of success increases from 75% to 90%, with success defined as complete or near complete occlusion of the aneurysm combined with a modified Rankin score of less or equal to 2.	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
modified Rankin score	modified Rankin score at discharge, and at 3 and 12 months post-treatment (last observation carried forward)	discharge, 3 and 12 months
rate of peri-operative complications	rate of ischemic strokes and intracranial hemorrhages during the peri-operative period	30 days
rate of Adverse Events	rate of new stroke, neurological symptom or sign during follow-up	12 months
angiographic outcome	degree of occlusion of aneurysm as assessed by invasive or non-invasive imaging (last observation carried forward	12 months
rate of retreatment of index aneurysm	rate of retreatment of index aneurysm due residual aneurysm after initial treatment	12 months

Collaborators and Investigators

• Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)
• Collaborators: Centre de Recherche du Centre Hospitalier de l'Université de Montréal
• Investigators: Principal Investigator: Jean Raymond, MD, Centre Hospitalier de l'Université de Montréal - Hôpital Notre Dame

Publications and helpful links

General Publications

• Raymond J, Gentric JC, Darsaut TE, Iancu D, Chagnon M, Weill A, Roy D. Flow diversion in the treatment of aneurysms: a randomized care trial and registry. J Neurosurg. 2017 Sep;127(3):454-462. doi: 10.3171/2016.4.JNS152662. Epub 2016 Nov 4.

Study record dates

Study Major Dates

• Study Start (Actual): May 2, 2011
• Primary Completion (Actual): January 1, 2023
• Study Completion (Actual): January 1, 2023

Study Registration Dates

• First Submitted: May 4, 2011
• First Submitted That Met QC Criteria: May 5, 2011
• First Posted (Estimated): May 6, 2011

Study Record Updates

• Last Update Posted (Actual): July 6, 2023
• Last Update Submitted That Met QC Criteria: July 4, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: endovascular treatment; flow diversion; symptomatic aneurysm; cavernous carotid aneurysm; ophthalmic aneurysm; vertebral aneurysm
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Intracranial Arterial Diseases; Aneurysm; Intracranial Aneurysm
• Other Study ID Numbers: CE10.206