PT - JOURNAL ARTICLE AU - Brinjikji, W. AU - Cloft, H.J AU - Kallmes, D.F. TI - Difficult Aneurysms for Endovascular Treatment: Overwide or Undertall? AID - 10.3174/ajnr.A1633 DP - 2009 Sep 01 TA - American Journal of Neuroradiology PG - 1513--1517 VI - 30 IP - 8 4099 - http://www.ajnr.org/content/30/8/1513.short 4100 - http://www.ajnr.org/content/30/8/1513.full SO - Am. J. Neuroradiol.2009 Sep 01; 30 AB - BACKGROUND AND PURPOSE: Aneurysm geometry has been shown to predict the need for adjunctive techniques in the endovascular treatment of intracranial aneurysms. We conducted a systematic retrospective study examining which thresholds of dome-to-neck ratio, maximum neck width, and aspect ratio of intracranial aneurysms best predict the need for adjunctive techniques in endovascular management. MATERIALS AND METHODS: One hundred seventy-five consecutive patients who were selected for attempted embolization of 185 intracranial aneurysms were included in this study. Aneurysm dome-to-neck ratio (maximum dome width/maximum neck width), maximum neck width, and aspect ratio (dome height/maximum neck width) were measured on 2D digital subtraction angiography. Statistical analysis was conducted to determine which thresholds of dome-to-neck ratio, maximum neck width, and aspect ratio were most predictive of the need for adjunctive devices in endovascular management of these aneurysms. RESULTS: We demonstrated that 75% of aneurysms with dome-to-neck ratios >1.6 (P < .0001), 75% of aneurysms with aspect ratios >1.6 (P < .0001), and 70% of aneurysms with neck diameters <4.0 mm (P < .0001) did not need adjunctive techniques in their management. Adjunctive techniques were essential to treatment of 80% of aneurysms with dome-to-neck ratios <1.2 (P = .02) and 89% of aneurysms with aspect ratios <1.2 (P < .0001). Multivariate logistic regression analysis demonstrated that aspect ratio was the best predictor of the need for an adjunctive device (P = .0004). CONCLUSIONS: Aneurysms with aspect and dome-to-neck ratios >1.6 usually did not require adjunctive techniques. Aneurysms with aspect and dome-to-neck ratios <1.2 almost always required adjunctive techniques. In this single-center series, aspect ratio was the independent predictor of the need for adjunctive techniques in the endovascular management of intracranial aneurysms.