[Surgical treatment of proximal middle cerebral artery (M1) aneurysms at the origin of the lenticulostriate artery].

In contrast to aneurysms of the middle cerebral artery at the bifurcation, aneurysms at the origin of the lenticulostriate arteries (LSA) are uncommon. Six surgically treated patients (34 to 70 year-old; 3 men, 3 women) were reviewed. 5 patients presented with subarachnoid hemorrhage (H&H grade 2:3, 3:1, 4:1; Fisher type 2:1, 3:3, 4:1) and 2 patients had multiple aneurysms. All aneurysms arose from the postero-superior surface of the M1. Although neck clipping was achieved in every patient, re-application of the clip was necessary during surgery in 3 patients because the tip of the blade extended to the other perforators that ran parallel to the M1. Results were as follows: GR 3, MD1, SD 1, D1. Apart from a 70 year-old patient who died of vasospasm (H & H 4), fair results in two patients were accompanied by ischemic complications of the LSA. All 3 patients who required re-application of the clip during surgery showed a lacunar infarct of perforating arteries on post-operative CT. Special care of perforating arteries not only around the neck (the LSA) but also behind the aneurysm is essential for successful neck-clipping of aneurysms at this location.