title: In vivo behavior of epoxy-crosslinked porcine heart valve cusps and walls.
abstract: Calcification limits the long-term durability of xenograft glutaraldehyde-crosslinked heart valves. In this study, epoxy-crosslinked porcine aortic valve tissue was evaluated after subcutaneous implantation in weanling rats. Non-crosslinked valves and valves crosslinked with glutaraldehyde or carbodiimide functioned as control. Epoxy-crosslinked valves had somewhat lower shrinkage temperatures than the crosslinked controls, and within the series also some macroscopic and microscopic differences were obvious. After 8 weeks implantation, cusps from non-crosslinked valves were not retrieved. The matching walls were more degraded than the epoxy- and control-crosslinked walls. This was observed from the higher cellular ingrowth with fibroblasts, macrophages, and giant cells. Furthermore, non-crosslinked walls showed highest numbers of lymphocytes, which were most obvious in the capsules. Epoxy- and control-crosslinked cusps and walls induced lower reactions. Calcification, measured by von Kossa-staining and by Ca-analysis, was always observed. Crosslinked cusps calcified more than walls. Of all wall samples, the non-crosslinked walls showed the highest calcification. It is concluded that epoxy-crosslinked valve tissue induced a foreign body and calcification reaction similar to the two crosslinked controls. Therefore, epoxy-crosslinking does not represent a solution for the calcification problem of heart valve bioprostheses.
authors.affiliation: University of Groningen, Faculty for Medical Sciences, Medical Biology; Cell Biology and Biomaterials, Bloemsingel 10-B2, 9712 KZ Groningen, The Netherlands.
authors.forename: P B
authors.initials: PB
authors.lastname: van Wachem
authors.forename: L A
authors.initials: LA
authors.lastname: Brouwer
authors.forename: R
authors.initials: R
authors.lastname: Zeeman
authors.forename: P J
authors.initials: PJ
authors.lastname: Dijkstra
authors.forename: J
authors.initials: J
authors.lastname: Feijen
authors.forename: M
authors.initials: M
authors.lastname: Hendriks
authors.forename: P T
authors.initials: PT
authors.lastname: Cahalan
authors.forename: M J
authors.initials: MJ
authors.lastname: van Luyn
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D002114:Calcinosis / Q000209:etiology / Q000473:pathology; D002234:Carbodiimides; D020099:Coated Materials, Biocompatible; D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D005976:Glutaral; D006350:Heart Valve Prosthesis; D008297:Male; D008422:Materials Testing; D011475:Prosthesis Failure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013552:Swine
chemical_list: D002234:Carbodiimides; D020099:Coated Materials, Biocompatible; D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D005976:Glutaral