The authors introduce the azygos anterior cerebral artery (ACA) bypass as an option for revascularizing distal ACA territories, as part of a strategy to trap giant anterior communicating artery (ACoA) aneurysms. In this procedure, the aneurysm is exposed with an orbitozygomatic-pterional craniotomy and distal ACA vessels are exposed with a bifrontal craniotomy. The uninvolved contralateral A2 segment of the ACA serves as a donor vessel for a short radial artery graft. The contralateral pericallosal artery (PcaA) and the callosomarginal artery (CmaA) are connected to the graft in the interhemispheric fissure using the double reimplantation technique. Three anastomoses create an azygos system supplying the entire ACA territory, enabling the surgeon to trap the aneurysm incompletely. Retrograde flow from the CmaA supplies the ipsilateral recurrent artery of Heubner, and the aneurysm lumen thromboses.
The azygos bypass was successfully performed to treat a 47-year-old woman with a giant, thrombotic ACoA aneurysm supplied by the A1 segment of the left ACA, with left PcaA and CmaA originating from the aneurysm base.
The authors conclude that the azygos ACA bypass is a novel option for revascularizing PcaA and CmaA, as part of the overall treatment of giant ACoA aneurysms.