Fibrin sealant coated stents compared with non-coated stents in a porcine carotid artery model. Preliminary study report.
BACKGROUND
Balloon expandable metal stents (BEMS) are used to treat restenosis following percutaneous transluminal angioplasty (PTA) and as primary treatment. Intimal proliferation (IP) and resultant restenosis occurs in 25-50% of patients despite all preventive measures.


OBJECTIVE
to test the intra-arterial response to the insertion of a fibrin sealant (FS) coated BEMS vs an uncoated BEMS by measuring endothelization and IP.


OBJECTIVE
that a BEMS coated with FS will lead to rapid endothelization and prevent or reduce IP.


BACKGROUND
FS consists of fibrinogen and thrombin. Thrombin affects endothelial cell proliferation and reduces smooth muscle proliferation, the forerunner of IP and restenosis. Normal endothelium also releases substances that promote vascular relaxation and normal smooth muscle tone regulation.


METHODS
Thirty-40 kg pigs (EA), Palmaz-Shatz BEMS (Cordis), FS Tissucol (Baxter Immuno). Stents were uniformly coated with FS in a special mold. Both coated and uncoated stents were mounted on balloon catheters and deployed caudad in the carotid arteries via an arteriotomy. Angiograms were obtained postdeployment. All specimens were examined grossly, photographed then fixed for histology and in some cases, scanning electron microscopy (SEM).


RESULTS
Fifteen animals form this preliminary report. Sacrifice at five days as per original protocol showed insufficient stent incorporation. Thereafter 1/2 of the animals were sacrificed at 15 days and 1/2 at 30 days. PATENCY: coated stents: 6 patent, 9 thrombosed. UNCOATED: 7 patent, 8 thrombosed. Of five EA given postoperatively low molecular weight heparin (LMWH) 4 animals had patent stents 80%.


RESULTS
varying degrees of IP were seen in all specimens. In general the coated stents showed a greater degree than the uncoated. STENOSIS: presacrifice angiography revealed that where the stents were patent no stenosis was present, in fact, some demonstrated mild dilatation. This was particularly the case with the coated stents.


CONCLUSIONS
Coating stents with FS is not detrimental. IP in these EA at 30 days did not produce stenosis. Postoperative LMWH appears helpful in maintaining patency in a thrombogenic experimental animal. Further study maintaining EA for 6-12 months should resolve whether the IP seen had achieved its maximum expression or would progress and produce stenosis.
Byer
A
A
Department of Surgery, New Jersey Medical School, Hackensack, NJ 07601, USA.
Peters
S
S
Settepani
F
F
Pagliaro
M
M
Galletti
G
G
D000800:Angioplasty, Balloon; D000818:Animals; D002339:Carotid Arteries / Q000254:growth & development*; D003251:Constriction, Pathologic / Q000209:etiology / Q000517:prevention & control; D004730:Endothelium, Vascular / Q000254:growth & development*; D015718:Fibrin Tissue Adhesive; D015607:Stents; D013552:Swine; D017539:Tunica Intima / Q000254:growth & development; D014654:Vascular Patency
D015718:Fibrin Tissue Adhesive