Improved biocompatibility of bioprosthetic heart valves by L-glutamic acid treatment.
Treatment of glutaraldehyde-fixed pericardium with L-glutamic acid and storage in bacteriostatic preservatives (paraben) stably antagonizes free, reactive aldehyde groups within the fixed bioprosthetic heart valve tissue. In 63-day subcutaneous implants in rats, the calcification rate of this treatment (13.3 +/- 2 mg calcium/g wt tissue) was markedly reduced as compared to conventionally treated tissue (169 +/- 24 mg/g; p less than 0.05). To test the influence of tissue-released toxic aldehydes on spontaneous endothelial cell ingrowth in vivo, vascular grafts (8-cm long, 6-mm diameter) from fixed pericardium treated with L-glutamic acid were interposed into the carotid arteries in ten sheep. They were compared to grafts from conventionally treated pericardium implanted at the contralateral side. Following 3 months of implantation, planimetry revealed 49% +/- 20% of the surface of conventionally preserved pericardium to be covered with red thrombus, but only 12% +/- 5% in L-glutamic acid treated pericardium (p less than 0.05). The ultrastructural findings of a closed endothelial cell layer on the graft surface reveals the new technique to be a promising approach towards increased biocompatibility of aldehyde-fixed bioprosthetic heart valves.
2nd Department of Surgery, University of Vienna, Austria.
M
M
Grimm
M
M
Grabenwöger
E
E
Eybl
A
A
Moritz
P
P
Böck
M M
MM
Müller
E
E
Wolner
D000818:Animals; D001672:Biocompatible Materials; D001705:Bioprosthesis; D002114:Calcinosis; D002417:Cattle; D004727:Endothelium / Q000166:cytology; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D005976:Glutaral / Q000494:pharmacology; D006350:Heart Valve Prosthesis; D007249:Inflammation; D008422:Materials Testing; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D010496:Pericardium / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012756:Sheep; D013997:Time Factors; D014021:Tissue Preservation
D001672:Biocompatible Materials; D005971:Glutamates; D018698:Glutamic Acid; D005976:Glutaral