Thrombogenicity and related biological properties of heparin bonded collagen coated polyester and human umbilical vein prosthetic vascular grafts.
BACKGROUND
Multiple factors contribute to the process of prosthetic graft failure. Some of them are specifically related to the biological behavior of the used materials. To pursue the ideal substitute for the autologous vein graft, many materials have been taken into consideration. Of these, polyester (Dacron) and human umbilical vein (HUV, Dardik) bypass grafts have gained much attention in vascular surgical practice over the years. This study compares the results of both in vivo and in vitro investigations on graft thrombogenicity and neo-intimal formation in collagen-coated heparin bonded Dacron and in HUV bypass grafts. It is an adjunct to our clinical comparison of graft materials in infrainguinal arterial reconstruction.


METHODS
In 12 adult Beagle dogs, a patch was sewn onto the abdominal aorta (Dacron, n = 6; HUV, n = 6). At defined interval times, thrombocyte aggregation was measured with nuclear imaging of 99mTechnetium labeled platelets. Post-mortem histological analysis of the interface between the native vessel wall and the patch was performed in all animals.


RESULTS
At 4 h (2.67, SD = 0.77) and after 2 weeks (2.21, SD = 0.28) after implantation, significantly higher thrombogenicity was measured in the HUV grafts compared to Dacron grafts (1.98, SD = 0.10 and 1.98, SD = 0.11, P = 0.02 and 0.025, respectively). At 4 weeks, no significant difference could be found (HUV, 2.26; SD = 0.29; Dacron, 2.11; SD = 0.16; P = 0.23). Measurement of 'neo-intimal' thickness after explantation of the patch at 28 days after the initial procedure showed a significant difference: in HUV grafts the mean thickness of the inner lining was 0.76 mm (SD = 0.50), compared to 0.16 mm (SD = 0.10) in the Dacron grafts (P = 0.013).


CONCLUSIONS
HUV grafts showed a higher thrombogenicity at 4 h and 2 weeks after insertion of the graft compared to Dacron grafts. At 4 weeks this difference is not present. After 28 days the inner ('neo-intimal') lining is significantly more pronounced in HUV grafts than in Dacron grafts.
Department of Vascular Surgery, University Medical Center Nijmegen, AD Doetinchem, The Netherlands. d.scharn@hccnet.nl
Dirk M
DM
Scharn
Wim J G
WJ
Oyen
Peter L
PL
Klemm
Albert A J
AA
Verhofstad
J Adam
JA
van der Vliet
D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D003094:Collagen / Q000737:chemistry; D004285:Dogs; D006493:Heparin / Q000737:chemistry; D006801:Humans; D010974:Platelet Aggregation; D011091:Polyesters; D011093:Polyethylene Terephthalates; D013927:Thrombosis / Q000209:etiology*; D013997:Time Factors; D014471:Umbilical Veins
D011091:Polyesters; D011093:Polyethylene Terephthalates; D006493:Heparin; D003094:Collagen