The variations of lenticulostriate arteries in the middle cerebral artery aneurysms

This study attempts to analyse the intra-operative anatomical findings of the lenticulostriate artery (LSA) in 60 patients with middle cerebral artery (MCA) aneurysms who were operated on at the Neurosurgical Department of Ataturk University Medical School, Erzurum, Turkiye. All patients underwent radical surgery for aneurysm by the right or left pterional approach. The findings were recorded during surgical intervention using slides and videotapes of the operations. On average there were 4 (range, 1-14, total number = 240) LSAs, in one hemisphere, per case with MCA aneurysm. Twenty percent of LSAs (n = 48) arise from the prebifurcation part of the M(1) segment, 65% (n = 156) arise from the postbifurcation part of the M(1) segment, and 15% (n = 36) arise from the proximal part of the M(2) segment. The great majority of the LSAs (85%, n = 204) orginated along the proximal part of the MCA. Of a total of 240 LSAs, 125 (52%) originated from one single large vessel, a stem artery which then divided after 2-10 mm into many branches, 85 (35%) originated as two large proximal trunks, and 30 (13%) originated as multiple small arteries arising along the whole infero-medial wall of the Ml segment of MCA. We concluded that recognition of the anatomical variations of the LSA and detailed knowledge of the microvascular relationships of the MCA aneurysms, will allow neurosurgeons to construct a better and safer microdissection plan, to save time, and to prevent postoperative neurological deficits.