title: Long-term safety of an everolimus-eluting bioresorbable vascular scaffold and the cobalt-chromium XIENCE V stent in a porcine coronary artery model.
abstract: BACKGROUND
  The Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb) has shown promising clinical results; however, only limited preclinical data have been published. We sought to investigate detailed pathological responses to the Absorb versus XIENCE V (XV) in a porcine coronary model with duration of implant extending from 1 to 42 months.
  
  
  RESULTS
  A total of 335 devices (263 Absorb and 72 XV) were implanted in 2 or 3 main coronary arteries of 136 nonatherosclerotic swine and examined by light microscopy, scanning electron microscopy, pharmacokinetics, and gel permeation chromatography analyses at various time points. Vascular responses to Absorb and XV were largely comparable at all time points, with struts being sequestered within the neointima. Inflammation was mild to moderate (with absence of inflammation at 1 month) for both devices, although the scores were greater in Absorb at 6 to 36 months. Percent area stenosis was significantly greater in Absorb than XV at all time points except at 3 months. The extent of fibrin deposition was similar between Absorb and XV, which peaked at 1 month and decreased rapidly thereafter. Histomorphometry showed expansile remodeling of Absorb-implanted arteries starting after 12 months, and lumen area was significantly greater in Absorb than XV at 36 and 42 months. These changes correlated with dismantling of Absorb seen after 12 months. Gel permeation chromatography analysis confirmed that degradation of Absorb was complete by 36 months.
  
  
  CONCLUSIONS
  Absorb demonstrates comparable long-term safety to XV in porcine coronary arteries with mild to moderate inflammation. Although Absorb was associated with greater percent stenosis relative to XV, expansile remodeling was observed after 12 months in Absorb with significantly greater lumen area at ≥ 36 months. Resorption is considered complete at 36 months.
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Otsuka
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Erica
authors.initials: E
authors.lastname: Pacheco
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Laura E L
authors.initials: LE
authors.lastname: Perkins
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Lane
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Marika
authors.initials: M
authors.lastname: Kamberi
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Michael
authors.initials: M
authors.lastname: Frie
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sakakura
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Yahagi
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Elena
authors.initials: E
authors.lastname: Ladich
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Rapoza
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.).
authors.forename: Frank D
authors.initials: FD
authors.lastname: Kolodgie
authors.affiliation: From the CVPath Institute, Inc, Gaithersburg, MD (F.O., E.P., K.S., K.Y., E.L., F.D.K., R.V.); Abbott Vascular, Santa Clara, CA (L.E.L.P., J.P.L., Q.W., M.K., J.W., R.J.P.); and American Preclinical Services, Minneapolis, MN (M.F.). rvirmani@cvpath.org.
authors.forename: Renu
authors.initials: R
authors.lastname: Virmani
mesh_terms: D020341:Absorbable Implants / Q000009:adverse effects*; D000818:Animals; D002858:Chromium Alloys / Q000009:adverse effects*; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology* / Q000648:ultrastructure; D054855:Drug-Eluting Stents / Q000009:adverse effects*; D000068338:Everolimus; D015994:Incidence; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D058426:Neointima / Q000000981:diagnostic imaging / Q000473:pathology; D020123:Sirolimus / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D015607:Stents / Q000009:adverse effects*; D013552:Swine; D013556:Swine, Miniature; D013997:Time Factors; D054457:Tissue Scaffolds / Q000009:adverse effects*; D014657:Vasculitis / Q000453:epidemiology
chemical_list: D002858:Chromium Alloys; D000068338:Everolimus; D020123:Sirolimus
keywords: coronary disease; pathology; stents