Flow Diversion for the Treatment of MCA Bifurcation Aneurysms-A Single Centre Experience

Abstract

Background: Intracranial aneurysms located at the bifurcation of the middle cerebral artery (MCA) can often be challenging for the neurointerventionalist. We aimed to evaluate the efficacy and safety of flow diverting stents (FDS) in the treatment of these aneurysms.

Materials and methods: We retrospectively reviewed our prospectively maintained database to collect information for all patients with unruptured saccular bifurcation MCA aneurysms treated with FDS between January 2010 and January 2016. In addition to demographic data, we recorded the location, aneurysm characteristics, previous treatments, number and type of FDS, complications, and clinical and angiographic follow-up.

Results: Our search identified 13 patients (7 males) with an average age of 61.7 years (47-74 years). All patients had a single bifurcation aneurysm of the MCA, and none of the aneurysms were acutely ruptured. The average fundus size of the saccular aneurysms was 3 mm (range 1.5-10 mm). Follow-up studies were available for 12 patients. Based on the most recent follow-up angiograms, six aneurysms (50%) were totally occluded; five aneurysms (41.7%) showed only a small remnant; and one aneurysm (8.3%) remained unchanged. One patient suffered from an ischemic stroke with resultant permanent hemiparesis (mRS 3). In another case, there was an in-stent thrombosis during the intervention, which resolved upon intra-arterial infusion of Eptifibatide (mRS 0). There were no intra-operative vessel or aneurysm ruptures and no mortalities. Angiography of the covered MCA branches showed no change in the caliber or flow of the vessel in six (50%), a reduction in caliber in five (41.7%), and a complete occlusion in one (8.3%). All caliber changes and occlusions of the vessels were asymptomatic.

Conclusion: In our series, 91.7% of treated MCA bifurcation aneurysms were either completely occluded or showed only a small remnant with a good safety profile. Flow diversion of MCA bifurcation aneurysms should be considered as an alternative treatment strategy when microsurgical clipping or alternative endovascular treatment options are not feasible.

Keywords: MCA aneurysm; MCA bifurcation; P64; Stents; flow diverter; pipeline embolization device.

Figure 1

A small neck recurrence after a previous coiling (A). Repeat treatment using coils would have necessitated a stent into the inferior branch, and therefore, it was felt an alternative strategy would be to place a single p64 FDS into the superior middle cerebral artery trunk. A follow-up angiogram performed 3 months later (B) showed on contrast enhancement of the aneurysm and a reduction in the caliber of the size of the inferior trunk but with persistent anterograde flow. The patient was neurologically intact, and there were no clinical consequences of the vessel modification.

Figure 2

A patient treated with a single p64 FDS for a middle cerebral artery bifurcation anerurysm. An incidental untreated bifurcation aneurysm (A). The same aneurysm in a different projection shows a wide necked saccular MCA bifurcation (B). There were no intra-operative complications and immediately post-procedure the patient awoke with baseline neurology. Five days post-procedure, the patient developed a right hemiparesis. Catheter angiography at this time (C) showed all branches were patent with anterograde flow and minimal filling of the aneurysm. An MRI showed restricted diffusion (D).