Nishi Shogo, Nakayama Yasuhide, Ishibashi-Ueda Hatsue, Okamoto Yoshihiro, Yoshida Masato
Department of Neurosurgery, Interventional Neurosurgery, and Spinal Surgery, Sapporo-Higashi Tokushukai Hospital, 14-3-1 Higashi, N33, Higashi-ku, Sapporo, Hokkaido 065-0033, Japan.
J Artif Organs. 2011 Dec;14(4):348-56. doi: 10.1007/s10047-011-0581-9. Epub 2011 Jun 23.
Treatment of large (diameter 12-25 mm) or giant (diameter >25 mm) cerebral aneurysms with a broad neck in the cranio-cervical area is difficult and carries relatively high risks, even with surgical and/or endovascular methods. To this end, we have been developing a high-performance, self-expanding stent graft which consists of a commercially available NiTi stent (diameter 5 mm, length 20 mm) initially covered with a thin microporous segmented polyurethane membrane fabricated by the dip-coating method. Micropores are then created by the excimer laser ablation technique, and the outer surface is coated with argatroban. There are 2 types of micropore patterns: circular-shaped pore type (pore: diameter 100 μm, opening ratio 12.6%) and the bale-shaped pore type (pore: size 100 × 268 μm, opening ratio 23.6%). This self-expanding stent graft was tested on side-wall aneurysms of both canine carotid arteries that were experimentally induced using the venous pouches from the external jugular veins, with the self-expanding stent graft on one side and a bare self-expanding stent on the other side. All carotid arteries were patent and free of marked stenosis after 1 month. All aneurysms were occluded by stent grafts, while patent in those treated with bare stents. Histologically, the stent grafts with bale-shaped micropores and a high opening ratio were associated with less intimal hyperplasia (187 ± 98 μm) than the bare stents (341 ± 146 μm) or the stent grafts with circular micropores and a low opening ratio (441 ± 129 μm). A pore ratio of 23.6% was found to control intimal growth.
治疗颅颈区域大（直径12 - 25毫米）或巨大（直径>25毫米）且颈部宽阔的脑动脉瘤很困难，即使采用手术和/或血管内方法，风险也相对较高。为此，我们一直在研发一种高性能的自膨胀支架移植物，它由市售的镍钛合金支架（直径5毫米，长度20毫米）组成，最初覆盖有通过浸涂法制造的薄微孔分段聚氨酯膜。然后通过准分子激光烧蚀技术制造微孔，并在其外表面涂上阿加曲班。有两种微孔图案：圆形孔型（孔：直径100微米，开孔率12.6%）和草捆形孔型（孔：尺寸100×268微米，开孔率23.6%）。这种自膨胀支架移植物在犬类颈动脉的侧壁动脉瘤上进行了测试，这些动脉瘤是使用来自颈外静脉的静脉囊袋实验性诱导产生的，一侧放置自膨胀支架移植物，另一侧放置裸自膨胀支架。1个月后，所有颈动脉均保持通畅且无明显狭窄。所有动脉瘤均被支架移植物闭塞，而用裸支架治疗的动脉瘤仍保持通畅。组织学上，具有草捆形微孔且开孔率高的支架移植物与内膜增生较少（187±98微米）相关，而裸支架（341±146微米）或具有圆形微孔且开孔率低的支架移植物（441±129微米）内膜增生较多。发现23.6%的开孔率可控制内膜生长。
