ORIGINAL ARTICLES   

International Angiology 2002 September;21(3):244-9

Copyright © 2003 EDIZIONI MINERVA MEDICA

lingua: Inglese

Matrigel-coated stents reduce intimal thickening in a large animal vascular stent model

Tso C. ¹, Skinner M. P. ¹, Hawthorne W. J. ², Fletcher J. P. ²

¹ Department of Cardiology, Westmead Hospital, NSW, Australia 2 Department of Surgery, University of Sydney, NSW, Australia

Background. Restenosis with­in vas­cu­lar ­stents is pri­mar­i­ly due to inti­mal thick­en­ing sec­on­dary to inti­mal hyper­pla­sia (IH) which ­occurs max­i­mal­ly ­around stent ­struts. Dedifferentiation of vas­cu­lar ­smooth mus­cle cells (VSMC) with sub­se­quent migra­tion and pro­life­ra­tion is ­believed to be a key event in IH for­ma­tion. Matrigel (base­ment mem­brane pro­tein) has been shown to inhib­it dedif­fe­ren­ti­a­tion of VSMC in vitro. Our aim was to test the in vivo ­effect of Matrigel on IH for­ma­tion using a novel sheep vas­cu­lar stent model.
Methods. Twenty vas­cu­lar ­stents were implant­ed in the renal arter­ies of ten sheep. The left renal ­artery of each sheep was used to ­deploy uncoat­ed stent and the right renal ­artery was used to ­deploy Matrigel-coat­ed stent. Five sheep were ana­lysed at four weeks and five at eight weeks after stent implan­ta­tion. The sheep were sac­ri­ficed at the end of the study peri­ods and the stent­ed renal ­artery seg­ments were exam­ined by his­tol­o­gy. Luminal, inti­mal and medi­al areas were deter­mined using com­put­er-assist­ed mor­pho­met­ric anal­y­sis.
Results. All stent sites were wide­ly pat­ent with­out throm­bo­sis. No lumi­nal sten­o­sis was seen angio­graph­i­cal­ly. IH was quan­ti­fied from his­tol­o­gy cross-sec­tions and ­expressed as an inti­ma to media (I/M) ratio. The ratio was sig­nif­i­cant­ly ­reduced in the mat­ri­gel-coat­ed sites at eight weeks (uncoated 0.49±0.23; Matrigel-coat­ed 0.32±0.12; p value <0.05).
Conclusions. The sheep renal ­artery vas­cu­lar stent model is fea­sible for the study of stent biol­o­gy. IH was ­reduced by Matrigel-coat­ed ­stents.