Initial and 6-month results of biodegradable poly-l-lactic acid coronary stents in humans

Background-Although metallic stents are effective in preventing acute occlu sion and reducing late restenosis after coronary angioplasty, many concerns still remain. Compared with metallic stents, poly-l-lactic acid (PLLA) ste nts are biodegradable and can deliver drugs locally. The aim of this study was to evaluate the feasibility, safety, and efficacy of the PLLA stent. Methods and Results-Fifteen patients electively underwent PLLA Igaki-Tamai stent implantation for coronary artery stenoses. The Igaki-Tamai stent is m ade of a PLLA monopolymer, has a thickness of 0.17 mm, and has a zigzag hel ical coil pattern. A balloon-expandable covered sheath system was used, and the stent expanded by itself to its original size with an adequate tempera ture. A total of 25 stents were successfully implanted in 19 lesions in 15 patients, and angiographic success was achieved in all procedures. No stent thrombosis and no major cardiac event occurred within 30 days. Coronary an giography and intravascular ultrasound were serially performed 1 day, 3 mon ths, and 6 months after the procedure. Angiographically, both the restenosi s rate and target lesion revascularization rate per lesion were 10.5%; the rates per patient were 6.7% at 6 months. Intravascular ultrasound findings revealed no significant stent recoil at 1 day, and they revealed stent expa nsion at follow-up. No major cardiac event, except for repeat angioplasty, developed within 6 months. Conclusions-Our preliminary experience suggests that coronary PLLA biodegra dable stents are feasible, safe, and effective in humans. Long-term follow- up with more patients will be required to validate the long-term efficacy o f PLLA stents.