Flow diversion in anterior cerebral artery aneurysms

Anterior cerebral artery (ACA) aneurysms are commonly encountered in clinical practice but can be challenging to treat. Flow diversion is a viable treatment in this population.

We retrospectively evaluated patients treated at our center from May 2017 to December 2020 who underwent flow diversion for an ACA aneurysm at or distal to the anterior communicating artery (ACOM). We defined ACA aneurysms as any aneurysm involving the ACOM itself, at the junction of the ACA with the ACOM (A1/A2), or in distal A2/A3 branches; both ruptured and unruptured aneurysms were included. Baseline and follow-up clinical and angiographic data were collected; the primary measure was elimination of the aneurysm on follow-up angiogram. Patients underwent flow diversion with a Pipeline stent. A single flow diverting stent was placed in the dominant ACA spanning from the A2 segment extending into the A1 segment; two patients required H-pipe technique. Distal aneurysms were treated with a single Pipeline device deployed across the parent vessel, covering the aneurysm.

Two-seven patients underwent a total of 28 flow diversion procedures; median age was 57 and 16 (59.3%) were male. Thirteen (48.2%) patients presented with subarachnoid hemorrhage; of these, four were treated within 6 weeks of the index hemorrhage. Most patients (22; 81.5%) had significant ACA asymmetry. There was one postoperative intracerebral hemorrhage and one groin complication. Follow-up data were available for 19 patients, 15 (78.9%) of which showed no residual aneurysm and 17 (89.5%) had protection of the dome.

Flow diversion of ACA aneurysms can be a primary treatment modality in an unruptured aneurysm or a complement to initial coil protection of a ruptured aneurysm. Further studies are needed to confirm these results.