Reduction of intimal hyperplasia with Re-188-labeled stents in a rabbit model at 7 and 26 weeks: an experimental study.
The aim of this study was to analyze the feasibility of (188)Re-labeled stents to reduce neointimal formation in a rabbit atherosclerosis model and to test the long-term effects at 7 and 26 weeks. Fifty-nine male New Zealand White rabbits were fed a 0.5% cholesterol diet for 4 weeks before balloon angioplasty and insertion of Palmaz stents in the infrarenal aorta. The animals were sacrificed 7 and 26 weeks after stent implantation. Control stents were compared with (188)Re stents: (dose 1) 11.3 +/- 1.8 MBq; (dose 2) 37.3 +/- 4.2 MBq, and (dose 3) 80.1 +/- 7.8 MBq. Each activity group consisted of a short-term (7 weeks) and a long-term group (26 weeks), resulting in a total of eight study groups. No thrombotic occlusion was observed. The neointimal formation in the control group was 2.11 [95% confidence interval (CI): 0.68--6.52] mm(2) at 7 weeks and 2.10 (0.62--7.11) at 26 weeks. In the treatment groups, neointima reduction was detectable at 7 weeks [dose 1: 0.33 (0.09--1.22) mm(2); dose 2: 0.17 (0.05--0.57) mm(2); dose 3: 0.03 (0.01--0.13) mm(2)]. After 26 weeks, a catch-up of neointimal formation in the radioactive groups was most obvious in the low-dose group [dose 1: 0.80 (0.28--2.29) mm(2); dose 2: 0.18([0.06--0.52) mm(2); dose 3: 0.50 (0.17--1.42) mm(2)]. Compared to the long-term control group, neointimal reduction was still >60%. No induction of neointimal formation was observed at the edges of the stents. Radiation resulted in delayed re-endothelialization. (188)Re stents were capable to reduce intimal hyperplasia and did not cause thrombosis. The edge effect, which was the major limitation of (32)P stents, was not observed in (188)Re stents.
Tepe
Gunnar
G
Department of Diagnostic Radiology, University of Tübingen, Tübingen, Germany. gunnar.tepe@med.uni-tuebingen.de
Dietrich
Tobias
T
Grafen
Franziska
F
Brehme
Ute
U
Muschick
Peter
P
Dinkelborg
Ludger M
LM
Greschniok
Annette
A
Claussen
Claus D
CD
Duda
Stephan H
SH
D000818:Animals; D001012:Aorta, Abdominal / Q000166:cytology / Q000473:pathology / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000473:pathology; D005240:Feasibility Studies; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000517:prevention & control; D006965:Hyperplasia / Q000601:surgery; D008297:Male; D011817:Rabbits; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D012211:Rhenium; D015607:Stents; D013997:Time Factors; D017539:Tunica Intima / Q000166:cytology / Q000473:pathology* / Q000601:surgery*
D011868:Radioisotopes; D019275:Radiopharmaceuticals; D012211:Rhenium