OBJECTIVE: Distal anterior cerebral artery (DACA) aneurysms are rare, representing only 2% to 6.7% of all intracranial aneurysms. Most of them are small. Large and giant aneurysms are even rarer in this location. Only 26 giant pericallosal (PC) aneurysms have been reported thus far. Various surgical techniques have been used to treat these aneurysms, including direct aneurysm neck clipping, aneurysm trapping, proximal occlusion of the anterior cerebral artery, or a combination of clipping with coiling or a bypass procedure. The report presents an unusual case of a complex DACA aneurysm managed by resection and interposition arterial graft. CLINICAL PRESENTATION: A 69-year-old woman presented with acute onset of a severe headache. A digital subtraction angiogram showed a partially thrombosed, complex broad-necked A2-A3 junction aneurysm involving the origin of PC and callosomarginal vessels with a probability of a dissection of the DACA. The left PC artery was significantly narrowed. Because of the complex neck and involvement of the origin of PC and callosomarginal arteries, endovascular treatment was not possible, and microsurgical treatment was planned. TECHNIQUE: A large, partially thrombosed, and fusiform anterior cerebral artery A2-A3 aneurysm, with evidence of previous bleeding, was found and treated with resection and a short interposition graft using a segment of the superficial temporal artery. CONCLUSION: Surgical treatment of a large DACA aneurysm may be difficult due to a complex neck and the involvement of the branch vessels. Resection and interposition grafting and A3-A3 or A4-A4 anastomoses are treatment options for such patients.
OBJECTIVE: Distal anterior cerebral artery (DACA) aneurysms are rare, representing only 2% to 6.7% of all intracranial aneurysms. Most of them are small. Large and giant aneurysms are even rarer in this location. Only 26 giant pericallosal (PC) aneurysms have been reported thus far. Various surgical techniques have been used to treat these aneurysms, including direct aneurysm neck clipping, aneurysm trapping, proximal occlusion of the anterior cerebral artery, or a combination of clipping with coiling or a bypass procedure. The report presents an unusual case of a complex DACA aneurysm managed by resection and interposition arterial graft. CLINICAL PRESENTATION: A 69-year-old woman presented with acute onset of a severe headache. A digital subtraction angiogram showed a partially thrombosed, complex broad-necked A2-A3 junction aneurysm involving the origin of PC and callosomarginal vessels with a probability of a dissection of the DACA. The left PC artery was significantly narrowed. Because of the complex neck and involvement of the origin of PC and callosomarginal arteries, endovascular treatment was not possible, and microsurgical treatment was planned. TECHNIQUE: A large, partially thrombosed, and fusiform anterior cerebral artery A2-A3 aneurysm, with evidence of previous bleeding, was found and treated with resection and a short interposition graft using a segment of the superficial temporal artery. CONCLUSION: Surgical treatment of a large DACA aneurysm may be difficult due to a complex neck and the involvement of the branch vessels. Resection and interposition grafting and A3-A3 or A4-A4 anastomoses are treatment options for such patients.