Flow Diversion in Intracranial Aneurysm Treatment
Condition: Intracranial Aneurysm
MeSH terms: Intracranial Aneurysm; Aneurysm
Study type: Interventional

Summary: 
      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.
    

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.
    

Intervention name(s): flow diversion; conservative management; endovascular coiling; balloon parent vessel occlusion; surgical clipping
Intervention type(s): Procedure; Other; Procedure; Procedure; Procedure
Intervention description(s): endovascular treatment with flow diversion including standard management of thrombo-embolic risk; conservative management is watchful observation of the aneurysm until indication for intervention arises; standard endovascular coiling of aneurysm with any type of already approved coil. High porosity stents may be used as an adjunct technique to coiling; sacrifice of parent artery of aneurysm by endovascular balloon occlusion with or without bypass; clipping of the aneurysm following invasive brain surgery
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: flow diversion; endovascular treatment; symptomatic aneurysm; cavernous carotid aneurysm; ophthalmic aneurysm; vertebral aneurysm