Assessment of prosthetic vascular graft thrombogenicity using the technetium-99m labeled glycoprotein IIb/IIIa receptor antagonist DMP444 in a dog model.
BACKGROUND
Prosthetic graft patency greatly depends on graft thrombogenicity. The concept of graft thrombogenicity is poorly understood and difficult to measure or quantify. In a study we tested the experimental radiopharmaceutical DMP444 and developed a suitable dog model. This agent is a radiolabelled ((99m)Technetium) glycoprotein IIb/IIIa receptor antagonist with a high affinity for activated platelets. It binds to platelets that are intimately involved in thrombus formation. The agent does not affect thrombocyte function, when used in a dose necessary for imaging. DMP444 does not require platelet harvesting and processing. Early imaging of thrombocyte aggregation sites such as vascular prostheses is possible within 4 hours after injection.


METHODS
Adult Beagle dogs weighing 12-15 kg were used for the experiments. In 16 dogs a prosthetic patch was sewn onto the abdominal aorta (Bovine pericard: n=4, Dacron: n=6, Human Umbilical Vein: n=6). Imaging cycles after injection of (99m)Technetium-labelled DMP444 were performed on days 1, 7, 14 and 28 after surgery.


RESULTS
We noticed differences in thrombus formation on the tested graft materials. The bovine pericard patches (n=4) showed a relatively high rate of thrombocyte aggregation. In the Dacron patches (n=6) aggregation was not seen. In 1 of 6 cases of human umbilical vein patches a measurable focal aggregation was recorded.


CONCLUSIONS
The method outlined in this study is a relatively simple and reproducable method to visualize thrombocyte aggregation.
Scharn
Dirk M
DM
Department of Surgery, University Medical Center Nijmegen, 'St Radboud', PO Box 9101, 6500 HB, Nijmegen, The Netherlands. d.scharn@hccnet.nl
Oyen
Wim J G
WJ
Klemm
Peter L
PL
Wijnen
Marc H W A
MH
vanderVliet
J Adam
JA
D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology; D001705:Bioprosthesis / Q000009:adverse effects; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D019917:Blood Vessel Prosthesis Implantation; D004195:Disease Models, Animal; D004285:Dogs; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D008422:Materials Testing; D009842:Oligopeptides; D015609:Organotechnetium Compounds; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology
C411949:DMP 444; D009842:Oligopeptides; D015609:Organotechnetium Compounds; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019275:Radiopharmaceuticals