Development of self-expandable covered stents.

We newly developed self-expandable covered stents by combining two of our original technologies. Of these, the first is the dip-coating covering method that was developed previously for balloon-expandable stents; the other is the newly developed self-expandable Nitinol stents, namely, Sendai stents. The three types of covered stents with the expansion diameter of 4.5, 5.0, or 6.0 mm thus obtained had a laser-processed microporous elastomeric cover film (pore diameter: 100 microm, interpore distance: 250 microm). Although the film was extremely thin (approximately 15 microm), the film could be expanded without causing any damage, the strut was completely embedded within the film, and the luminal surface of the film was smooth and flat. Mechanical properties such as ideal flexibility to follow the shapes of arteries were almost retained even after covering. As appropriate drugs, the blood-contacting inner and tissue-contacting outer surfaces of the film were differentially coated with argatroban for antithrombogenicity or FK506 for anti-inflammation, respectively. The preliminary in vivo study indicated that the covered stents mounted in the delivery catheter were navigated and placed to appropriate position in the arteries, and permissible neointimal thickening after 1-month implantation was observed similarly in noncovered stents.

Synthesis of novel glucose-based polymers and their applications as chiral stationary phases for high performance liquid chromatography.

Two novel polymers containing glucose units as the main-chain that only differ in terms of their regioregularity were synthesized to evaluate their chiral recognition abilities as chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC). The regioregular polymer (poly-5) shows clear resolution ability for the racemate of cobalt (III) acetylacetonate (Co(acac)3), whereas the corresponding regioirregular polymer (poly-3) does not show any chiral recognition for Co (acac)3. The regioregular polymer main-chain seems to play an important role not only in providing an efficient interaction with the racemate but also in expressing the chiral recognition ability as a CSP for HPLC.

Pelvic arteriovenous malformation treated by transarterial glue embolisation combining proximal balloon occlusion and devascularisation of multiple feeding arteries.

We present a case of a 70-year-old man with abdominal aortic aneurysm and coincident pelvic arteriovenous malformation (AVM). Before the operation for the aneurysm, we embolised the pelvic AVM that had multiple feeding arteries and an aneurysmal-dilated draining vein. After decreasing the number of the feeding arteries by coil embolisation, an n-butyl-2-cyanoacrylate/lipiodol mixture (1:1) was injected into the prominent feeding artery and nidus with proximal balloon occlusion of the right internal iliac artery to decrease the flow to the nidus. The mixture (1:4-8) was also added for the finer feeding arteries that became apparent after the initial procedure to embolise the rest of the nidus. A follow-up study showed no contrast enhancement of the nidus and aneurysmal draining vein.