Endovascular coil placement compared with surgical clipping for the treatment of unruptured middle cerebral artery aneurysms: a consecutive series

Object. The goal of this study was to delineate the angioanatomical feature s that determine whether st patient with an unruptured middle cerebral arte ry (MCA) aneurysm is treated using endovascular coil placement or surgical clipping. Methods. Thirty consecutive patients harboring 34 unruptured MCA aneurysms were evaluated. Patients with unruptured aneurysms are managed prospectivel y according to the following protocol: the primary treatment recommendation is endovascular packing with Guglielmi detachable coils (GDCs). Surgical c lipping is recommended after failed attempts at coil placement or in the pr esence of angioanatomical features that contraindicate that type of endovas cular therapy. Of 34 unruptured MCA aneurysms, two (6%) were successfully embolized and 32 (94%) were clipped. Of these 32 surgically treated aneurysms, in 11 (34%) an attempt at GDC embolization had failed, whereas in 21 (66%) primary clip ping was performed because of unfavorable angioanatomy. Of the 13 aneurysms treated endovascularly, two (15%) were successfully excluded. whereas GDC treatment failed in 11 (85%). An unfavorable dome/neck ratio (< 2) and an a rterial branch originating at the aneurysm base were the reasons for emboli zation failure. Conclusions. Careful evaluation of the angioanatomy of unruptured aneurysms allows selection of the most appropriate treatment. However, for unrupture d MCA aneurysms, surgical clipping appears to be the most efficient treatme nt option. Series of unruptured aneurysms are ideal for comparing treatment results.