Blood flow alterations after flow diverter placement using the AneurysmflowTM tool

Abstract

Purpose: We used AneurysmFlow software (Philips Healthcare) on DSA to analyze flow characteristics in aneurysms after Flow Diverter Stent (FDS) treatment.
Methods: 18 patients with unruptured cerebral aneurysms were treated for FDS at the Bach Mai Radiology Center. First, a 3D rotational angiogram of the aneurysm was acquired. Then, two high frame rate DSA sequences were acquired before and right after the implantation of the FDS with a contrast injection of 1.5 ml/sec for a duration of 4s. The aneurysmal flow was calculated before - after the implantation of the FDS for each patient.
Results: The aneurysmal flow was significantly reduced after implantation of the FDS (p=0.001 < 0.05), the mean reduction was about 19.51%. However, 4 aneurysms (21.05%) had increased flow after treatment. The pulsatility of aneurysmal flow is reduced after the insertion of the flow diverter. This reduction of the aneurysmal flow does not differ by aneurysm size (large and medium aneurysm, p = 0.612) and aneurysm morphology (smooth and irregular, lobe, knob, bilobar; p = 0.625). The MAFA ratio in the study is variable and mostly was less than 1, but all aneurysms in the study were complete obliteration at 6 months after the intervention.
Conclusion: Significant reductions in flow inside the aneurysm were observed after implantation of the FDS. There was no difference in the reduction of aneurysmal flow after intervention according to aneurysm size and morphology.