Recurrence of a totally occluded aneurysm after treatment with a pipeline embolization device

Abstract

Treatment with a pipeline embolization device (PED) is widely accepted as an excellent option for patients harboring giant, wide neck, saccular intracranial aneurysms. It has been shown to be safe and very effective. We describe a previously unreported case of a large middle cerebral artery aneurysm, related to the carotid tip, that was treated with a PED and coils. The 6 month follow-up angiogram demonstrated complete occlusion of the aneurysm. However, the 9 month angiogram revealed recurrent filling of the aneurysm sac. To our knowledge, this is the first report to describe recanalization of an aneurysm totally occluded on the control angiography after treatment with a PED. Unanswered questions include the mechanism of recanalization and the need for additional control angiograms and MRI following a previous examination revealing total aneurysm occlusion.

Flow diversion for treatment of intracranial aneurysms: Mechanism and implications

“…A recent case report showed angiographic evidence of aneurysm recurrence at 9-month follow-up despite complete occlusion on angiography at the 6-month follow-up post-treatment with a PED FD and coils. 49 Zhang et al have also shown recurrence of a completely occluded aneurysm treated with a Tubridge FD at the 2-year followup. 51 FD treatment can also delay aneurysm rupture through aneurysm wall thrombus-associated autolysis.…”

“…45,46 FD treatment failure is usually attributed to inadequate coverage of the aneurysm, presence of a pre-existing stent, presence of an incorporated branch, or endoleak analogous to that seen in endovascular abdominal aortic aneurysm repair. 49,50 Dai et al reported on a basilar tip aneurysm treated with a PED FD that showed complete occlusion on angiography at 4 months, with subsequent recurrence at 12 months. Other mechanisms that could explain recurrence are branch vessel runoff or improper endothelialization and thrombus formation leading to aneurysm recurrence and delayed rupture despite angiographic evidence of complete occlusion.…”

“…49,50 Dai et al reported on a basilar tip aneurysm treated with a PED FD that showed complete occlusion on angiography at 4 months, with subsequent recurrence at 12 months. 49 Zhang et al have also shown recurrence of a completely occluded aneurysm treated with a Tubridge FD at the 2-year followup. Similarly, Szikora et al reported complete occlusion of aneurysms treated with a FD at 13 months, with endothelialization occurring as early at 6 months.…”

“…Other mechanisms that could explain recurrence are branch vessel runoff or improper endothelialization and thrombus formation leading to aneurysm recurrence and delayed rupture despite angiographic evidence of complete occlusion. 49,50 Dai et al reported on a basilar tip aneurysm treated with a PED FD that showed complete occlusion on angiography at 4 months, with subsequent recurrence at 12 months. 50 Histopathological examination revealed unorganized thrombus within the aneurysm cavity, with interrupted thick neointima across the neck.…”

“…However, these do not explain recurrence in completely occluded aneurysms. Other mechanisms that could explain recurrence are branch vessel runoff or improper endothelialization and thrombus formation leading to aneurysm recurrence and delayed rupture despite angiographic evidence of complete occlusion . Dai et al reported on a basilar tip aneurysm treated with a PED FD that showed complete occlusion on angiography at 4 months, with subsequent recurrence at 12 months .…”