Percutaneous delivery of a heparin-impregnated collagen stent-graft in a porcine model of atherosclerotic disease.
OBJECTIVE
To develop collagen stent-grafts impregnated with heparin to improve the biocompatibility of endovascular stents and to design a percutaneous delivery system for graft deployment in a swine model.


METHODS
Heparin-impregnated collagen stent-grafts were deployed, and follow-up angiograms were obtained every 15 minutes for 90 minutes to assess acute thromboses and again at 2 and 4 weeks afterward to assess patency. If stenosis or occlusion was detected at the 2-week evaluation, guidewire passage across the lesion was attempted and angioplasty was performed. If stenosis or occlusion was present at the 4-week evaluation, only guidewire passage was attempted; thereafter, the animals were killed and the stent-grafts were harvested and reviewed by a vascular pathologist.


RESULTS
Group A represents a feasibility study to optimize the deployment method applied in groups B and C. Fifteen of 17 stent-grafts were successfully deployed using this method. In group B, 89% of grafts were successfully deployed; 12% were patent at 2 weeks and none at 4 weeks. In group C, a 10-minute inflation time was added to the deployment procedure; 88% of grafts were successfully deployed and 28% were patent at 2 weeks and 14% at 4 weeks. Extensive luminal thrombosis and myointimal hyperplasia were present in every case.


CONCLUSIONS
A method was developed for percutaneous implantation of collagen stent-grafts into peripheral vessels. The heparin-impregnated grafts did not prevent vessel restenosis. Modification of the graft-processing technique may improve patency.
Goodwin
S C
SC
Department of Radiological Sciences, University of California, Los Angeles Medical Center, 90095, USA.
Yoon
H C
HC
Wong
G C
GC
Bonilla
S M
SM
Vedantham
S
S
Arora
L C
LC
D000818:Animals; D001161:Arteriosclerosis / Q000628:therapy*; D001672:Biocompatible Materials; D019917:Blood Vessel Prosthesis Implantation; D003094:Collagen; D005240:Feasibility Studies; D006083:Graft Occlusion, Vascular / Q000517:prevention & control; D006493:Heparin / Q000008:administration & dosage; D007601:Jugular Veins / Q000637:transplantation; D015607:Stents; D013552:Swine
D001672:Biocompatible Materials; D006493:Heparin; D003094:Collagen