An unusual variant of the common trunk of the fronto-orbital and frontopolar arteries associated with a ruptured aneurysm of the A1 segment of the anterior cerebral artery

BACKGROUND: The common trunk of the fronto-orbital artery (FOA) and frontopolar artery (FPA) arising from the A1 segment of the anterior cerebral artery (ACA) associated with a ruptured aneurysm (AN), is rare. CASE DESCRIPTION: The patient was a 52-year-old man who suffered from subarachnoid hemorrhage. Three-dimensional computed tomography angiography revealed an elongated and tortuous left A1 segment of the ACA and a saccular AN arising from the left A1 segment of the ACA at the origin of the cortical branch, defining its location just on the midline and behind the anterior communicating artery. This vessel had two branches. One branch ran along the inferior surface of the ipsilateral frontal lobe, and the other branch ran anteriorly and medially along the surface of the left hemisphere toward the frontal pole. The anomalous artery was interpreted as a common trunk of the FOA and FPA. Bifrontal craniotomy was performed. The anomalous artery arose from the A1 segment of the ACA at the origin of the AN, and the recurrent artery of Heubner branched off the anomalous artery. The AN was successfully obliterated, clipping with a bayonet-shaped Yasargil titanium clip. Complete AN occlusion and patency of both the A1 and the common trunk of the FOA and FPA, were confirmed intraoperatively by indocyanine green angiography. CONCLUSIONS: Recognizing this variant preoperatively, could be helpful in preventing the complications of surgery.