Bovine type I collagen as an endovascular stent-graft material: biocompatibility study in rabbits.
OBJECTIVE
To study the biocompatibility of a bovine type I collagen preparation as a material for small-vessel stent-grafts in rabbits.


METHODS
A composite nitinol-collagen endovascular stent-graft with a 4-mm inner diameter was deployed in the abdominal aorta in nine rabbits. Angiography was performed, and the rabbits were sacrificed at 1, 2, and 7 days and at 1 and 3 months. The portion of the aorta containing the stent-graft was excised and was histologically evaluated.


RESULTS
All stent-grafts were patent at all time points. On days 1, 2, and 7 after implantation, scattered red and white blood cells adhered to the stent-graft. At 1 month, the stent-graft was endothelialized and was infiltrated with fibroblasts that deposited collagen within the interstices of the implanted collagen material. At 3 months, there was additional collagen deposition within the interstices of the stent-graft that did not narrow the lumen of the stent-grafts.


CONCLUSIONS
Type I collagen as a intravascular stent-graft material is biocompatible for at least 3 months in rabbits. It is rapidly endothelialized and does not cause reactive stenosis. As a versatile and biocompatible polymer, collagen is potentially useful in the construction of endovascular stent-grafts for use in human arteries.
Cloft
H J
HJ
Dept of Radiology, University of Virginia Health Sciences Center, Charlottesville, USA. harry_cloft@emory.org
Kallmes
D F
DF
Lin
H B
HB
Li
S T
ST
Marx
W F
WF
Hudson
S B
SB
Helm
G A
GA
Lopes
M B
MB
McGraw
J K
JK
Dion
J E
JE
Jensen
M E
ME
D000497:Alloys / Q000737:chemistry; D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D001672:Biocompatible Materials / Q000737:chemistry; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation; D002417:Cattle; D002448:Cell Adhesion; D003094:Collagen / Q000737:chemistry / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000473:pathology; D004912:Erythrocytes / Q000473:pathology; D005347:Fibroblasts / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007962:Leukocytes / Q000473:pathology; D008422:Materials Testing; D011474:Prosthesis Design; D011817:Rabbits; D011859:Radiography; D015607:Stents; D013499:Surface Properties; D017539:Tunica Intima / Q000473:pathology; D014654:Vascular Patency
D000497:Alloys; D001672:Biocompatible Materials; C013616:nitinol; D003094:Collagen