Short-term effects of fully bioabsorbable PLLA coronary stents in a porcine model

Although metallic stents are effective in preventing acute occlusion and reducing late restenosis after coronary angioplasty, many concerns still remain. In this report, short-term effects of fully bioabsorbable sirolimus-loaded poly-l-lactic acid (PLLA) stents (Xinsorb) were evaluated in a porcine coronary model. Commercially available PLLA-coated sirolimus-eluting stents (Excel) were used as controls. The purpose of this study was to assess technical feasibility, biocompatibility, and impact on coronary stenosis of fully bioabsorbable PLLA stents. Our preliminary experience suggested that Xinsorb stents have succeeded in preventing elastic recoil and suppressing neointimal formation for the first 90 days and only mildly delayed the endothelialisation process of the stented blood vessel. Coronary stenosis following Xinsorb and Excel stent implantations after 30 and 90 days was 18.6 ± 5.2% versus 21.4 ± 7.2% and 24.5 ± 4.7% versus 27.7 ± 5.6%, respectively (p > 0.05). Both Xinsorb and Excel stents required approximately 1–3 months for re-endothelialization of the inner wall of stented blood vessels. These data provided additional insights into the mechanism and efficacy of fully bioabsorbable PLLA stents in normal porcine coronary arteries while raising questions regarding the potential durability of this novel medical device. Long-term follow-up will be required to validate the long-term efficacy of fully bioabsorbable PLLA stents.