Sadasivan Chander, Cesar Liliana, Seong Jaehoon, Wakhloo Ajay K, Lieber Baruch B
Department of Biomedical Engineering, Universityof Miami, Coral Gables, FL 33146, USA.
IEEE Trans Med Imaging. 2009 Jul;28(7):1117-25. doi: 10.1109/TMI.2008.2012162. Epub 2009 Jan 19.
It has been known for more than a decade that intracranial aneurysms can be successfully treated by deploying a porous meshed tube in the parent vessel of the aneurysm. Such devices are currently called flow diverters because they promote intraneurysmal flow stasis and thrombosis by diverting blood flow away from the aneurysm sac. The objective of this study was to use angiographic data to quantify and compare the performance of flow diverters of original design in successfully occluding an experimental aneurysm model. Three different configurations of a novel flow diverter with varying porosities and pore densities were implanted in 30 rabbit elastase-induced aneurysms. Temporal variations in angiographic contrast intensity within the aneurysms were fit to a mathematical model. Optimized model parameters were supplemented by the angiographic percentage aneurysm occlusion and an angiographic measure of device flexibility to derive composite scores of performance. Angiographic quantification further suggested a parameter, which could be employed to estimate long-term aneurysm occlusion probabilities immediately after treatment. Performance scores showed that the device with a porosity of 70% and pore density of 18 pores/mm (2) performed better than devices with 65% porosity, 14 pores/mm (2), and 70% porosity, 12 pores/mm (2) with relative efficacies of 100%, 84%, and 76%, respectively. The pore density of flow diverters, rather than porosity, may thus be a critical factor modulating device efficacy. A value of the prognostic parameter of less than 30 predicted greater than 97% angiographic aneurysm occlusion over six months with a sensitivity of 73% and specificity of 82%.
十多年来，人们已经知道，通过在动脉瘤的供血动脉中部署多孔网状管，可以成功治疗颅内动脉瘤。这种装置目前被称为血流导向装置，因为它们通过将血流从动脉瘤囊中转移，促进瘤内血流淤滞和血栓形成。本研究的目的是利用血管造影数据量化并比较原始设计的血流导向装置在成功闭塞实验性动脉瘤模型中的性能。将具有不同孔隙率和孔隙密度的新型血流导向装置的三种不同构型植入30个兔弹性蛋白酶诱导的动脉瘤中。动脉瘤内血管造影对比剂强度的时间变化符合一个数学模型。通过动脉瘤闭塞的血管造影百分比和装置柔韧性的血管造影测量来补充优化的模型参数，以得出综合性能评分。血管造影定量分析进一步提出了一个参数，可用于估计治疗后立即出现的长期动脉瘤闭塞概率。性能评分显示，孔隙率为70%、孔隙密度为18个孔/mm²的装置比孔隙率为65%、14个孔/mm²和孔隙率为70%、12个孔/mm²的装置表现更好，相对疗效分别为100%、84%和76%。因此，血流导向装置的孔隙密度而非孔隙率可能是调节装置疗效的关键因素。预后参数值小于30预测六个月内血管造影动脉瘤闭塞率大于97%，敏感性为73%，特异性为82%。
