Introduction: Partially thrombosed aneurysms (PTAs) can cause neurological deficits even when unruptured. Diverse treatment modalities have been attempted, none of which have proven to be superior. Flow-diversion (FD) has revolutionized the treatment of complex aneurysms, and here we explore the efficacy of FD in treating PTAs.
Methods: We retrospectively reviewed all aneurysms treated with FD at our institution since 2011. We compared clinical characteristics and outcomes of patients treated for PTAs with those treated for non-PTAs.
Results: Sixty-seven patients underwent FD, of which seven had PTAs. Patients were similar in age and aneurysm location. Mean angiographic follow up was 11.5 months. There was a nonsignificant reduction in technical complications in the PTA group (14% vs 29%, p=.669). The PTA group had significantly higher rates of late complications at 12 months (71% vs 13%, p=0.002) and treatment failure (defined as aneurysmal persistence) at last follow-up (83% vs 12%, p=0.001). There were fewer patients with modified Rankin scores (mRS) 0-1 in the PTA group immediately post-operatively (57% vs 92%, p=0.032) as well as at 12 month clinical follow-up (60% vs 94%, p=0.049).
Conclusions: The association of PTA and increased risk of FD treatment failure is not well described in the literature. In PTA patients, FD was not associated with increased rates of intraoperative technical complications. However, it was associated with a higher rate of late complications and eventual treatment failure compared to aneurysms without thrombosis. Most concerning is the group of patients who experienced post-treatment enlargement of the thrombotic portion of the aneurysm without significant change in the angiographic imaging. This is the first report in the literature to describe higher rates of treatment failures specifically with this rare subtype of intracranial aneurysm. Based on our experience, we advise selective and cautious use of FD for PTA.
Patient Care: The findings of our study represent a first step in understanding the utility and limitations of a revolutionary new technology in treating a challenging clinical entity without any currently satisfactory treatment options.
Learning Objectives: (1) To review the difficulty in treating partially thrombosed aneurysms
(2) To determine the utility of flow diversion in treating PTAs