title: Novel fully bioabsorbable salicylate-based sirolimus-eluting stent.
abstract: OBJECTIVE
  The concept of fully biodegradable stents has emerged as an attractive alternative to current permanent metallic stents, mainly as a potential solution to avoid late stent thrombotic events. We sought to evaluate a novel, fully bioabsorbable sirolimus-eluting stent (SES) synthesised entirely from a unique salicylic-acid polymer, in a clinically relevant animal model.
  
  
  RESULTS
  Fully biodegradable balloon-expandable stents (n=45) were implanted in a porcine coronary arteries using quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) to optimise stent apposition. Dose density of sirolimus was 8.3 µg/mm of stent length with in vitro studies demonstrating elution over 30 days and complete stent degradation over 12 months. Animals were terminated at 7, 14, 30, 90, and 180 days for complete histological analysis. Optical coherence tomography (OCT) was also performed for the 90- and 180-days samples. All stents were deployed successfully without notable mechanical difficulties. Angiographic diameter stenosis (DS) was 20±16%, 24±4%, and 23±17%, at one, three, and six months, respectively. In parallel, IVUS showed good stent apposition with DS of 21±9%, 25±7%, and 18±3%; and area stenosis (AS) of 35±13%, 33±7%, and 32±4% at one, three, and six months,respectively. OCT further demonstrated good stent apposition with DS of 28±7% and 20±6%, and AS of 37±10% and 33±13% at three and six months, respectively. OCT showed reduction of stent thickness by 23% from three to six months. Histologic analysis confirmed these in vivo findings and revealed a favourable healing process of absorbable stent incorporation into the arterial wall, without excessive thrombotic or inflammatory reactions.
  
  
  CONCLUSIONS
  This study shows favourable vascular compatibility and efficacy for a novel fully bioabsorbable salicylate-based SES. This device has good mechanical performance during deployment and stays well-apposed to the vessel wall at long-term follow-up. These initial results are highly encouraging and support progress into more extensive preclinical studies as well as early clinical testing.
authors.affiliation: Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel. jabara@hadassah.org.il
authors.forename: Refat
authors.initials: R
authors.lastname: Jabara
authors.forename: Lakshmana
authors.initials: L
authors.lastname: Pendyala
authors.forename: Sarah
authors.initials: S
authors.lastname: Geva
authors.forename: Jack
authors.initials: J
authors.lastname: Chen
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chronos
authors.forename: Keith
authors.initials: K
authors.lastname: Robinson
mesh_terms: D020341:Absorbable Implants; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D000818:Animals; D002317:Cardiovascular Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D054855:Drug-Eluting Stents; D008422:Materials Testing; D023421:Models, Animal; D011474:Prosthesis Design; D020156:Salicylic Acid / Q000737:chemistry*; D020123:Sirolimus / Q000008:administration & dosage* / Q000493:pharmacokinetics; D034421:Sus scrofa; D013997:Time Factors; D041623:Tomography, Optical Coherence; D018084:Ultrasonography, Interventional
chemical_list: D002317:Cardiovascular Agents; D020156:Salicylic Acid; D020123:Sirolimus