A Clinical Study On The Related Factors Which Can Affect The Endovascular Treatment Strategy Of Intracranial Wide-necked Aneurysms

Background and Objectives:Intracranial wide-necked aneurysm is still one of the challenging issues in the field of interventional neuroradiology, largely due to the technical difficulties in their endovascular management and high recurrence rate after treatment. Although various approaches are available, a strategic selection of the proper one, as well as its efficacies, is affected by multiple factors. In this study, we aimed to retrospectively investigate and evaluate the factors affecting the endovascular treatment strategies of intracranial wide-necked aneurysms, with an intention to find some worthy information in improving the therapeutic efficacy of this type of disorders.Methods:Patients with wide-necked aneurysm(s) who received endovascular treatment in our centre between Jan,2007and Dec,2011were analyzed retrospectively with particular attention on the following aspects.1) Morphological characteristics:such as the aneurysm shape, size, location, neck size (N), dome-to-neck ratio (D/N), height-to-diameter transversa ratio (H/D) and the diameter of parent artery.2) Clinical and imaging records:including the patients’presentations, results of treatment, technique data, procedure related complications, and the clinical and imaging follow-up information. Data were statistically processed by either single-factor X2or multi-factor logistic regression analysis. Results are represented as frequency or ratio and mean±SD accordingly for un-continuous variants and continuous variants, respectively.Results:1)210patients with wide-necked aneurysms (in total of238aneurysms) were included in the study. Among all the aneurysms,154were ruptured and84un-ruptured, representing64.71%and35.92%, respectively.200(84.03%) occurred in anterior circulation and38(15.97%) in the posterior circulation;88(36.97%) are bifurcation aneurysms and150(63.03%) lateral ones. The aneurysms are6.94±5.64mm (1.6-40mm) in size, with their neck size at4.11±2.47mm (1.0-20mm) in average; Average H/D is1.31±0.46(0.45-5.40).2) Among all the238aneurysms,237(99.58%) were received successful endovascular treatment except that one fell into abeyance because of the thrombosis during procedure, and81.01%of the237aneurysms got adequate embolization. Specifically,55(23.11%) received standard coiling,71(29.83%) balloon-assisted and79(33.19%) stent-assisted coiling,17(7.14%) a combined technique with both stent and balloon assisting,12(5.04%) sole stenting and12(7.14%) double catheter technique.3) Aneurysms with H/D≤1(OR=2.847, P=0.006) and with N≥4mm (OR=4.772, P=0.000) were well suited for stent-assisted embolization, while ruptured (OR=0.372, P=0.003) and bifurcation aneurysms were not. Aneurysms with N≥4mm were preferable for balloon-assisted embolization (OR=3.662, P=0.003), too. Ruptured ones (OR=0.311,P=0.006) and those with D/N≥1.5(OR=0.427, P=0.043) were prone to be chosen for standard coiling.4) The rate of adequate embolization is higher in ruptured than in un-ruptured aneurysms (OR=2.918, P=0.002). The aneurysms with H/D≤1are much more difficult to get adequate embolization (OR=0.399, P=0.010).5) All200patients but10in-hospital death got follow-up of24.60±16.28months in average. Among them7died.134aneurysms underwent imaging follow-up, showing87.31%of satisfactory evolution (including improvement and no-change) and12.69%of worsening. Worsening tend to happen in those patients with aneurysms more than15mm in size (OR=5.867, P=0.028).Conclusions:1) Satisfactory short-or midterm quality of occlusion could be expected for those wide-necked aneurysms receiving appropriately selected endovascular treatment.2) Standard coiling, balloon-or stent-assisted embolizations are the mainstream methods for the endovascular treatment of intracranial wide-necked aneurysms, with the stent-assisted embolization getting a rising tendency.3) Aneurysms with neck size≥4mm are suited for balloon-or stent-assisted embolization. For ruptured aneurysm and those with D/N≥1.5, the operators favors balloon-assisted or standard coiling much more than stenting. Aneurysms with≤1are more appropriate for stent-assisted embolization, yet this do not include aneurysms located at the bifurcation.4) Ruptured aneurysms and those with H/D>1win a higher rate of adequate embolization.5) Aneurysm size was the primary factor affecting the evolution of the aneurysms after endovascular treatment, and diameter>15mm was the only independent risk factor for recurrence in this study.