Department of Neuro-endovascular Therapy, Toranomon Hospital, Tokyo, Japan; and.
Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
J Neurosurg. 2016 Sep;125(3):705-12. doi: 10.3171/2015.7.JNS15238. Epub 2016 Jan 8.
OBJECTIVE The importance of a framing coil (FC)-the first coil inserted into an aneurysm during endovascular coiling, also called a lead coil or a first coil-is recognized, but its impact on long-term outcomes, including recanalization and retreatment, is not well established. The purposes of this study were to test the hypothesis that the FC is a significant factor for aneurysmal recurrence and to provide some insights on appropriate FC selection. METHODS The authors retrospectively reviewed endovascular coiling for 280 unruptured intracranial aneurysms and gathered data on age, sex, aneurysm location, aneurysm morphology, maximal size, neck width, adjunctive techniques, recanalization, retreatment, follow-up periods, total volume packing density (VPD), volume packing density of the FC, and framing coil percentage (FCP; the percentage of FC volume in total coil volume) to clarify the associated factors for aneurysmal recurrence. RESULTS Of 236 aneurysms included in this study, 33 (14.0%) had recanalization, and 18 (7.6%) needed retreatment during a mean follow-up period of 37.7 ± 16.1 months. In multivariate analysis, aneurysm size (odds ratio [OR] = 1.29, p < 0.001), FCP < 32% (OR 3.54, p = 0.009), and VPD < 25% (OR 2.96, p = 0.015) were significantly associated with recanalization, while aneurysm size (OR 1.25, p < 0.001) and FCP < 32% (OR 6.91, p = 0.017) were significant predictors of retreatment. VPD as a continuous value or VPD with any cutoff value could not predict retreatment with statistical significance in multivariate analysis. CONCLUSIONS FCP, which is equal to the FC volume as a percentage of the total coil volume and is unaffected by the morphology of the aneurysm or the measurement error in aneurysm length, width, or height, is a novel predictor of recanalization and retreatment and is more significantly predictive of retreatment than VPD. To select FCs large enough to meet the condition of FCP ≥ 32% is a potential relevant factor for better long-term outcomes. These findings support our hypothesis that the FC is a significant factor for aneurysmal recurrence.
目的
在血管内栓塞治疗中，首先放置的成篮圈（FC）——也称为引导圈或首枚线圈——非常重要，但它对长期结果（包括再通和再治疗）的影响尚未得到充分证实。本研究旨在验证 FC 是影响动脉瘤复发的重要因素这一假设，并提供有关选择合适 FC 的一些见解。
方法
作者回顾性分析了 280 例未破裂颅内动脉瘤的血管内栓塞治疗，并收集了年龄、性别、动脉瘤位置、动脉瘤形态、最大直径、瘤颈宽度、辅助技术、再通、再治疗、随访时间、总容积填塞密度（VPD）、FC 容积填塞密度、FC 百分比（FC 体积占总线圈体积的百分比，FCP）等数据，以明确与动脉瘤复发相关的因素。
结果
本研究共纳入 236 个动脉瘤，其中 33 个（14.0%）发生再通，18 个（7.6%）需要在平均 37.7±16.1 个月的随访中再次治疗。多因素分析显示，动脉瘤大小（比值比[OR] = 1.29，p < 0.001）、FCP < 32%（OR 3.54，p = 0.009）和 VPD < 25%（OR 2.96，p = 0.015）与再通显著相关，而动脉瘤大小（OR 1.25，p < 0.001）和 FCP < 32%（OR 6.91，p = 0.017）是再治疗的显著预测因素。VPD 作为连续值或任何截断值均不能在多因素分析中预测再治疗，统计学意义不显著。
结论
FCP 是 FC 体积占总线圈体积的百分比，不受动脉瘤形态或动脉瘤长度、宽度或高度测量误差的影响，是再通和再治疗的新预测因素，对再治疗的预测意义大于 VPD。选择足够大的 FC 以满足 FCP≥32%的条件可能是获得更好长期结果的一个相关因素。这些发现支持我们的假设，即 FC 是动脉瘤复发的重要因素。
