Nishi Shogo, Nakayama Yasuhide, Ishibashi-Ueda Hatsue, Masato Yoshida
Department of Neurosurgery, Interventional Neurosurgery, Spinal Surgery, Sapporo-Higashi Tokushukai Hospital, Sapporo, Hokkaido, Japan.
Department of Bioengineering, Advanced Biomedical Engineering Center, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
Clin Neurol Neurosurg. 2014 Jul;122:34-41. doi: 10.1016/j.clineuro.2014.04.013. Epub 2014 Apr 22.
The treatment of large or giant cerebral aneurysms by surgical and/or endovascular techniques is difficult and poses relatively high risks. Therefore, a microporous self-expanding (hybrid) stent graft composed of a thin, expandable, segmented polyurethane (SPU) membrane with micropores and a drug-delivery system was developed.
A commercially available, self-expanding carotid stent was covered with a thin microporous SPU membrane fabricated by the dip-coating method and the excimer laser ablation technique, with an intraluminal coating of argatroban. Experimentally fabricated lateral-wall aneurysms in canine carotid arteries using venous pouches were occluded with the hybrid stent graft (bale-shaped pore density of 23.6%) on one side and a bare-metal stent on the other side without systemic antiplatelet therapy.
Angiography at 1, 6, and 12 months of stenting revealed that all arteries were patent without marked stenosis without systemic antiplatelet therapy. All aneurysms treated with hybrid stent grafts remained occluded throughout the 12-month period, while among those treated by bare-metal stents, 2 of 3 aneurysms were occluded at 6 months (67%) and only 1 of 3 aneurysms were occluded at 12 months (33%). Histology revealed that the novel hybrid stent graft had less intimal hyperplasia than the bare-metal stent. The hybrid stent graft was useful for the successful occlusion of these canine carotid aneurysms, even at 12 months.
The novel hybrid stent grafts are expected to overcome the disadvantages of fully covered stent grafts and simple bare-metal stents, while combining both their merits, and appear to be useful in the treatment of large or giant cerebral aneurysms.
采用外科手术和/或血管内技术治疗大型或巨大型脑动脉瘤难度大且风险相对较高。因此，研发了一种由具有微孔的薄型、可扩张、分段聚氨酯（SPU）膜和药物递送系统组成的微孔自膨胀（混合）支架移植物。
用浸涂法和准分子激光烧蚀技术制备的薄型微孔SPU膜覆盖市售自膨胀颈动脉支架，并在内腔涂覆阿加曲班。使用静脉囊在犬颈动脉中实验性制造侧壁动脉瘤，一侧用混合支架移植物（球囊形孔密度为23.6%）闭塞，另一侧用裸金属支架闭塞，无需全身抗血小板治疗。
支架置入后1、6和12个月的血管造影显示，在未进行全身抗血小板治疗的情况下，所有动脉均通畅，无明显狭窄。所有接受混合支架移植物治疗的动脉瘤在整个12个月期间均保持闭塞，而在接受裸金属支架治疗的动脉瘤中，3个动脉瘤中有2个在6个月时闭塞（67%），3个动脉瘤中只有1个在12个月时闭塞（33%）。组织学检查显示，新型混合支架移植物的内膜增生比裸金属支架少。即使在12个月时，混合支架移植物也有助于成功闭塞这些犬颈动脉动脉瘤。
新型混合支架移植物有望克服完全覆盖支架移植物和单纯裸金属支架的缺点，同时兼具两者的优点，似乎可用于治疗大型或巨大型脑动脉瘤。
