Since the 1960s, several trials have described the implantation of aortic valves using transcatheter techniques. Since 1992, with the development of metallic stents, the combination of balloon-expandable metallic stent and pericardial valve (stent-valve) has become a potentially groundbreaking approach. The first implantation of an aortic stent-valve in a patient with severe calcific aortic stenosis was demonstrated in 2002. Since then, transcatheter aortic valve implantation (TAVI) has been under active investigation. Since 1996, we also have been trying to develop a novel aortic stent-valve using our original metallic stent. In this feature article, knowledge obtained through our preliminary experiments was described.

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Recently, transcatheter aortic valve implantation (TAVI) is attracting increasing attention across the globe. Aortic valve replacement for aortic valve stenosis has commonly achieved safety and excellent durability over a few decades. But this conventional surgery is still extremely invasive for elderly and high-risk patients. So less invasive surgical techniques are necessary, and we believe TAVI serves such a purpose. TAVI was started in 2002, mainly in Europe and Canada, and over 20000 cases have received TAVI worldwide until now. In 2009, we performed the first case of TAVI in Japan, and 22 cases have since received TAVI in our institution. The data of clinical trials are prohibited to be shown to the public, so in this session, we elucidated the results of four TAVI cases (transfemoral: 3, transapical: 1) by clinical research. In addition, several new devices for TAVI have already been launched in US and Europe. I will show you these new devices and discuss the future picture of TAVI.

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Endovascular stent graft treatment for aortic dissection was started from in 1993 in Japan and then spread all over the world. Although preliminary data using home-made device to close the entry site of aortic dissection was reported before the millennium, company-made devices have promoted the expert consensus of endovascular treatment for acute complicated type B dissection. For patient with uncomplicated type B dissection, endovascular treatment promises a better result for reverse remodeling of the false lumen. Stent graft treatment will be a promising therapeutic modality for aortic dissection.

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Thoracic endovascular aortic repair (TEVAR) is often done by proximal fixation, and the aortic stent graft may need to be extended beyond the origin of the aortic branches. Until recently, TEVAR has been limited to aneurysms not involving critical aortic branches due to the complex nature of designing a repair that would preserve important end-organ flow. We describe the chimney graft technique, which is an alternative to the fenestrated stent-graft and has been proposed to preserve flow into the branches during TEVAR. The indications included acute complicated type B dissection, ruptured aneurysms of the aortic arch, traumatic aortic transection, aortoesophageal fistula, and accidental over stenting of the left carotid artery during TEVAR. Chimney grafts were implanted into the innominate, left carotid, and left subclavian arteries. Use of a chimney graft makes it possible to use standard off-the-shelf stent-grafts to instantly treat lesions with inadequate fixation zones, providing an alternative to fenestrated stent-grafts in urgent cases. Our initial experience with this technique suggests that it is feasible in the aortic branches and may facilitate TEVAR in patients with an inadequate proximal fixation zone.

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This paper describes the points you should know when you file patent applications for doctors' ideas and inventions. It also summarizes the key points of patent application.
Furthermore, as the necessary information for productization and commercialization of doctors' invention and patents, the following topics are explained; the way to find appropriate business partners, the points for negotiation with other companies, and the organizations which promote Japanese medical industry.

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Purpose: To investigate normative data of the superior vena cava (SVC) anatomy using multi-detector row CT (MDCT) and determine the optimal tip-position of the central venous port catheter inserted via the peripheral veins in the left arm.
Material and Mthods: On the coronal images of MDCT in 48 patients as a control, the SVC length and distances between the carina and cavoatrial junction and between the cephalad margin of SVC and carina were measured using a workstation. The location of a catheter-tip in twenty-three patients with a central venous port catheter inserted via a peripheral veins in the left arm was categorized into two groups: group A (above or same level as the carina, n=14), group B (below the carina, n=9). We investigated catheter-related complications such as catheter dislodgement and venous thrombosis.
Results: According to the MDCT images in the control group, the mean distance from the carina to the cavoatrial junction was 35.3mm±7.4mm (95% confidence interval [CI]; 30mm, 40.6mm). The mean distance from the cephalad margin of the SVC to the carina was 28.5mm±5.6mm (95% CI; 24.5mm, 32.5mm). The catheter tip was dislodged into the left innominate vein in seven patients of group A, and venous thrombosis was seen in two of these patients. No significant complications in group B (26.8mm±7.6mm below the carina, 95% CI; 21.8mm, 31.8mm) were seen.
Conclusion: The position at approximately 3-4cm below the carina is near the cavoatrial junction. The optimal tip-position of the central venous port catheter should be 2-3cm below the carina.

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We analyzed adverse events associated with balloon-occluded transarterial chemoembolization (B-TACE) for hepatocellular carcinoma (HCC) in 107 treatments of 82 cases (group A). We also analyzed those associated with TACE using a conventional microcatheter in 310 treatments of 161 cases as a historical control (group B), and compared with group A. The adverse events in group A were death due to duodenal bleeding (n=1), biloma (n=1), skin necrosis (n=1), segmental atrophy (n=1), diaphragmatic paralysis (n=5), severe pain controlled with intravenous morphine (n=5), elevation of ALT level (grade 3: n=17, grade 4: n=5, classified by CTCAE version 4), and elevation of bilirubin level (grade 3: n=3, classified by CTCAE version 4). Those in group B were death due to liver failure and acute tumor lysis syndrome (n=2), biloma (n=4), diaphragmatic paralysis (n=6), severe pain controlled with intravenous morphine (n=7), elevation of ALT level (grade 3: n=12), and elevation of bilirubin level (grade 3: n=1). Elevation of ALT level was dominant in group A with a statistically significant difference (p=0.01, Kruskal-Wallis test). There were no significant differences in the incidence of other adverse events between the groups (p>0.2, Fisher's test, t-test, chi-square test, Kruskal-Wallis test). Dominant elevation of ALT level indicates that B-TACE caused more liver cell damage compared with conventional TACE. However, as far as the incidence of clinically manifested adverse events, B-TACE is as safe as conventional TACE.

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A case of a broken catheter fragment without free ends that was removed percutaneously is reported. A patient in his 70's had an indwelling central venous port system (CV port) for lung and colorectal cancer chemotherapy. The migrated catheter was difficult to capture with a common retrieval device, because neither ends of the catheter had any free ends. After moving the catheter to the IVC using an ablation catheter, successful retrieval was achieved. Ablation catheters appear to be useful for retrieving catheters without free ends that have migrated into the right atrium.

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Two cases of gastric varices in which a pericardiophrenic vein was a major draining route were treated by balloon-occluded retrograde transvenous obliteration (B-RTO) using a micro-balloon catheter.
In both cases, enhanced CT shows the pericardiophrenic vein was only approachable route for B-RTO. The varices were successfully treated by B-RTO via the pericardiophrenic vein with using the micro-balloon catheter in both cases. B-RTO with a conventional 5-Fr or 6-Fr balloon catheter seemed to be difficult due to the small and tortuous pericardiophrenic vein. The micro-balloon catheter allows highly selective treatment; this instrument can be advanced beyond the outlet of collateral vessels, and can minimize the amount of sclerosing agent. Using the micro-balloon catheter enhance successful procedure in B-RTO via the pericardiophrenic vein.

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