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1 Drug-eluting Stents in Vascular Intervention 1Department of Diagnostic Radiology, Keio University School of Medicine 2Department of Thoracic-Cardiovascular Surgery, Kitasato University School of Medicine NICHIDOKU-IHO Vol. 48 No (2003) Terumitsu Hasebe, M.D., 1 Subaru Hashimoto, M.D., 1 Seishi Nakatsuka, M.D., 1 Kazuhiro Matsumoto, M.D., 1 Atsushi Shimada, M.D., 2 Hirokuni Yoshimura, M.D., 2 and Sachio Kuribayashi, M.D. 1 Summary In-stent restenosis remains the major limitation of vascular stenting. The arterial response to injury is the basis for restenosis. The stent prevents remodeling but enhances intimal hyperplasia, which is principally responsible for in-stent restenosis. Morphology after coronary stenting demonstrates thrombus formation and acute inflammation early after deployment, with subsequent neointimal growth. The rationale for the most recent approaches to restenosis arises from the simi- larity between tumor-cell growth and the benign tissue proliferation that characterizes intimal hyperplasia. Several immunosuppressants (e.g., sirolimus) and antiproliferative drugs (e.g., paclitaxel) have been tested for their potential to inhibit restenosis, with the novel strategy of administrating the drug via a coated stent platform. Increasing focus has recently been directed toward the different parameters of drug-eluting stents stent design, deliveryvehicle materials, and drug properties and the manner in which each of these elements may affect the function of the stents. Stent-based local delivery is an attractive therapeutic option because stent coatings can optimize the surface properties of metallic devices and serve as a vehicle for local delivery. The RAVEL (randomized comparison of a sirolimus-eluting stent with a standard stent for coronary revascularization) and the SIRIUS [the United States (US) multicenter, randomized, double-blind study of sirolimus-eluting stent in de-novo coronary lesions], using a sirolimus eluting stent, report substantial reductions in clinical restenosis with drug-eluting stents compared with bare stents. The FDA (Food and Drug Administration of the United States Department of Health and Human Services) approved the CYPHER TM Sirolimus-eluting Coronary Stent in April CYPHER TM is now the first drug-eluting stent to be approved in the US to help reduce restenosis in the coronary artery. Paclitaxel-eluting stents also seem promising for the management of restenosis. There have been several trials involving the ASPECT (Asian Paclitaxel-eluting Stent Clinical Trial) and TAXUS (polymer-based paclitaxel-eluting stent) programs. Clinical TAXUS trials are now ongoing in the US. The ultimate choice of which drug-eluting stent to use and when will be determined by a combination of factors: further long-term efficacy and safety trial results, availability, cost, operator preference, and specific aspects of stent suitability for different subsets of lesions. Overall, drug-eluting stents appear to represent a major advance in the field of vascular intervention and promise to extend the application and effectiveness of percutaneous interventions to a wider patient population. This article will focus on the data for the most promising compounds that are now undergoing clinical trial.

D., 2 and Sachio Kuribayashi, M.D. 1 Summary In-stent restenosis remains the major limitation of vascular stenting. The arterial response to injury is the basis for restenosis.

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49-4 ™ñ„¾ Œ]„”†i4†j

49-4 ™ñ„¾ Œ]„”†i4†j Current Topics in Diagnostic Imaging of the Pediatric Neck Eiji Oguma, M.D. Department of Radiology, Saitama Children s Medical Center NICHIDOKU-IHO Vol. 49 No. 4 61 83 (2004) Summary This article focuses