Heparin-coated balloon-expandable stent reduces intimal hyperplasia in the iliac artery in baboons.
OBJECTIVE
To examine the effect of heparin-coated balloon-expandable iliac stent placement on intimal hyperplasia in a baboon model.


METHODS
Balloon-expandable (Palmaz-Schatz) stents were placed in bilateral common iliac arteries in 20 male baboons (mean weight: 8.8 kg). In each animal, a heparin-coated iliac stent was placed on one side and the contralateral iliac artery received an uncoated stent that served as a control. The iliac artery stents were harvested at 30 days (n = 10) and 90 days (n = 10). Arteriography was performed to assess iliac patency and intravascular ultrasonography was used to determine neointimal and luminal areas. Histologic and morphometric analysis and scanning electron microscopy were performed in the stent-implanted iliac arteries.


RESULTS
One animal was excluded in the 30-day group because of premature death. In the remaining nine surviving animals, seven control stents (78%) and nine heparin-coated stents (100%) remained patent. Morphometric analysis showed that the iliac arteries with heparin-coated stents had larger luminal areas (17%, P <.05), less neointimal area (26%, P <.05), lower neointima-to-media ratios (32%, P <.05), and equivalent medial areas (P =.92) compared to the control group at 30 days. In contrast, all control and heparin-coated stents were patent (100%) in the 90-day group. In that group, the heparin-coated stent group had less neointimal area (28%, P <.05), lower neointima-to-media ratios (42%, P <.05), and equivalent medial area (P =.92) and luminal area (P =.07) compared to the control group.


CONCLUSIONS
The data demonstrate that heparin-coated balloon-expandable stents reduce intimal hyperplasia after iliac artery stent placement. This approach may represent a useful strategy for prolonging luminal patency after iliac stent placement.
Lin
Peter H
PH
Division of Vascular Surgery & Endovascular Therapy, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, 2002 Holcomb Boulevard (112), Houston, Texas 77030, USA.
Chronos
Nicolas A
NA
Marijianowski
Monique M
MM
Chen
Changyi
C
Bush
Ruth L
RL
Conklin
Brian
B
Lumsden
Alan B
AB
Hanson
Stephen R
SR
D000818:Animals; D020099:Coated Materials, Biocompatible; D006493:Heparin; D006965:Hyperplasia; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008855:Microscopy, Electron, Scanning; D010215:Papio; D011859:Radiography; D015607:Stents; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D018084:Ultrasonography, Interventional; D014654:Vascular Patency
D020099:Coated Materials, Biocompatible; D006493:Heparin