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Kubo T.,Cardiovascular Research Foundation | Maehara A.,Cardiovascular Research Foundation | Mintz G.S.,Cardiovascular Research Foundation | Garcia-Garcia H.M.,Erasmus Medical Center | And 12 more authors.
American Heart Journal | Year: 2010

Background: Animal models show impairment of arterial healing after drug-eluting stents (DES) compared with bare-metal stents (BMS). Virtual histology intravascular ultrasound (VH-IVUS) offers an opportunity to assess lesion morphology in vivo. Methods: We used VH-IVUS in 80 patients to assess long-term (median = 10 months) native artery vascular responses after 76 implantations of DES compared with 32 BMS. The presence of "necrotic core abutting the lumen" was evaluated at baseline and follow-up. Results: At baseline, necrotic core abutting the lumen through the stent struts was observed in 76% of DES and 75% of BMS. Although the percentage of necrotic core within the plaque behind the stents did not change during follow-up in DES (23% [18%, 28%] to 22% [17%, 27%], P = .57) or BMS (22% [19%, 27%] to 20% [12%, 26%], P = .29), necrotic core abutting the lumen through the stent struts decreased more in BMS (75% to 19%, P < .001) than DES (76% to 61%, P = .036) because of the lack of an overlying, protective neointima in DES-treated lesions. Furthermore, within the adjacent reference segments, the incidence of necrotic core abutting the lumen decreased in BMS-treated lesions (proximal 23% to 0%, P = .023; distal 21% to 0%, P = .023), but not in DES (proximal 22% to 17%, P = .48; distal 23% to 21%, P = .82). Conclusions: Serial VH-IVUS analysis of DES-treated lesions showed a greater frequency of unstable lesion morphometry at follow-up compared with BMS. The apparent mechanism was a suppression of the protective neointimal hyperplasia layer coupled with a lack of vulnerable plaque resolution at reference segments in DES compared with BMS. © 2010 Mosby, Inc. All rights reserved. Source


Nishi S.,Neuro Intervention | Nakayama Y.,Japan National Cardiovascular Center Research Institute | Ishibashi-Ueda H.,Japan National Cardiovascular Center Research Institute | Yoshida M.,Nozaki Tokushukai Hospital | Yonetani H.,Neuro Intervention
Journal of Biomaterials Applications | Year: 2014

Objective: We sought to determine the patency of normal arterial branches from the covered segments of an artery after stenting. Background: Most intracranial aneurysms occur at arterial branching points (bifurcations, side-branches, or perforators). The post-stenting patency of normal arterial branches from the covered segments of the artery is important. We have previously developed a hybrid stent with micropores to prevent early parent artery occlusion by more early endothelialization, and mid- to long-term parent artery stenosis by control of intimal hyperplasia after aneurysm occlusion. Methods: We created aneurysms in 10 rabbits by distal ligation and intraluminal incubation of elastase within an endovascularly trapped proximal segment of the common carotid artery. All animals were treated with hybrid stents having micropores. Four animals were observed for one month and three each for three and 12 months. The patency of the side-branches of the subclavian artery was evaluated angiographically and in some cases, histologically. Results: Aneurysms were completely occluded at all time points other than 12 months. The subclavian artery and brachiocephalic artery were patent, without significant stenosis. All the side-branches of the subclavian artery detected on the preoperative angiogram remained patent at the final assessment. Conclusion: The use of hybrid stents for aneurysm repair and side-branch patency seems to be effective, as per the long-term results obtained in an animal model. © 2013 The Author(s). Source


Yoneda S.,Osaka Police Hospital | Kinjo T.,Osaka Police Hospital | Nonomura D.,Osaka Police Hospital | Yamamoto Y.,Osaka Police Hospital | And 5 more authors.
Acta Urologica Japonica | Year: 2013

Metastasis to the bone of the hand is rare. In addition, metastasis to the bone of the hand from bladder cancer is extremely rare. We herein report a case of distal phalanx metastasis from bladder cancer. A 64-year-old man who was diagnosed with bladder cancer (cT2bN0M0) received total cystectomy (pT3bN2). Two months after the surgery, a roentgenogram revealed lung metastasis. Then we administered 2 cycles of chemotherapy using gemcitabine and cisplatin. Computed tomography revealed a partial response. However, several months after chemotherapy, we noted that his left ring finger was swollen and showed erythema. We made a diagnosis of metastasis to the distal phalanx of the left ring finger and amputated the finger. Pathological findings showed no conflict with metastasis from bladder cancer. Postoperative course was good, but he died about three months after the diagnosis of metastasis. Source


Shogo N.,Interventional Neurosurgery | Yasuhide N.,Japan National Cardiovascular Center Research Institute | Hatsue I.-U.,Japan National Cardiovascular Center Research Institute | Yoshida M.,Nozaki Tokushukai Hospital
Clinical Neurology and Neurosurgery | Year: 2014

Purpose 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. Materials and methods 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. Results 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. Conclusions 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. © 2014 Elsevier B.V. Source


Nishi S.,Interventional Neurosurgery and Spinal Surgery | Nishi S.,Japan National Cardiovascular Center Research Institute | Nakayama Y.,Japan National Cardiovascular Center Research Institute | Ishibashi-Ueda H.,Japan National Cardiovascular Center Research Institute | And 2 more authors.
Journal of Artificial Organs | Year: 2011

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. © 2011 The Japanese Society for Artificial Organs. Source

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