Prophylaxis of restenosis with (186)re-labeled stents in a rabbit model.
BACKGROUND
Intraluminal beta-irradiation has been shown to decrease neointimal proliferation after angioplasty in experimental models. The purpose of this study was to test the technical feasibility and biological effects of (186)Re-labeled stents.


RESULTS
Thirty-four New Zealand White rabbits were fed a 0.5% cholesterol diet before balloon angioplasty and insertion of Palmaz stents in the infrarenal aorta. The animals were killed 7 weeks after stent implantation. Two of 34 animals died prematurely (aortic leak, pneumonia). Control stents (n=7) were compared with (186)Re stents (2.6 MBq [n=6], 8.1 MBq [n=5], 16.0 MBq [n=6], and 25.3 MBq [n=8]). Stent application was successful in all cases. No thrombus occlusion was observed. After 7 weeks, neointima formation was 2.2+/-0.2 mm(2) in the control group. In the treatment groups, a dose-dependent neointima reduction was detectable (0.5+/-0.5 mm(2) [2.6 MBq], 0.4+/-0.4 mm(2) [8.1 MBq], and 0 mm(2) [16.0 MBq, 25.3 MBq]). No induction of neointimal formation was observed at the edges of the stents. Radiation resulted in delayed reendothelialization.


CONCLUSIONS
(186)Re stents were capable of reducing neointima formation in a dose-dependent fashion. (186)Re stents did not cause late thrombosis or neointimal induction at the stent margins in the observation period of 7 weeks.
Tepe
G
G
Department of Diagnostic Radiology, Institute of Pathology, University of Tübingen, Germany. gunnar.tepe@med.uni-tuebingen.de
Dinkelborg
L M
LM
Brehme
U
U
Muschick
P
P
Noll
B
B
Dietrich
T
T
Greschniok
A
A
Baumbach
A
A
Claussen
C D
CD
Duda
S H
SH
D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology / Q000528:radiation effects / Q000601:surgery; D001157:Arterial Occlusive Diseases / Q000517:prevention & control*; D001918:Brachytherapy / Q000379:methods; D004195:Disease Models, Animal; D004307:Dose-Response Relationship, Radiation; D004730:Endothelium, Vascular / Q000473:pathology / Q000528:radiation effects; D005337:Fibrin / Q000378:metabolism; D006207:Half-Life; D008297:Male; D011817:Rabbits; D011868:Radioisotopes / Q000627:therapeutic use*; D012211:Rhenium / Q000627:therapeutic use*; D015607:Stents; D013997:Time Factors; D017539:Tunica Intima / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D017540:Tunica Media / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects
D011868:Radioisotopes; D012211:Rhenium; D005337:Fibrin