© 2001 by European Society of Cardiology
Copyright © 2000, European Society of Cardiology
Endovascular irradiation with the liquid β-emitter Rhenium-188 to reduce restenosis after experimental wall injury
aDepartment of Internal Medicine II, Cardiology, University of Ulm, Robert-Koch-Straße 8, D-89081 Ulm, Germany
bDepartment of Nuclear Medicine, University of Ulm, Ulm, Germany
* Corresponding author. Tel.: +49-731-502-4384; fax: +49-731-502-4442 markus.wohlfrom{at}medizin.uni-ulm.de
Objective: Postinterventional irradiation is a new therapeutic concept in the prevention of restenosis. The liquid β-emitter Rhenium-188 allows endovascular brachytherapy using a conventional balloon catheter without the problem of centering the radiation source. In an animal model of restenosis the feasibility and the dose dependent effect of intravascular brachytherapy with a Rhenium-188 filled balloon catheter was investigated. Methods: In 68 male New Zealand White rabbits after endothelial denudation of the right common carotid artery with a Fogarty catheter, endovascular irradiation was performed with a Rhenium-188 filled 3.0-mm balloon catheter using different dosages (0, 7.5, 15, 30, 45 and 60 Gy at the surface of the vessel). Then 4 weeks after the intervention the vessels were excised and histologically analyzed. Results: Whereas at 7.5 Gy the intimal area (median [first quartile; third quartile]) did not differ significantly from the control (0.46 mm2 [0.33 mm2, 0.75 mm2] vs. 0.49 mm2 [0.34 mm2, 0.66 mm2]), neointimal hyperplasia was decreased significantly at 15 Gy (0.15 mm2 [0.04 mm2, 0.17 mm2]) and 30 Gy (0.07 mm2 [0.04 mm2, 0.10 mm2]), and completely inhibited at the highest dosages (45 Gy: 0 mm2 [0 mm2, 0.04 mm2]; 60 Gy: 0 mm2 [0 mm2, 0.01 mm2]). Conclusions: Catheter transmitted endovascular irradiation with the liquid β-emitter Rhenium-188 after vascular injury is feasible and effectively reduced neointimal hyperplasia in hypercholesterolemic rabbits. A significant reduction of the neointimal formation could be found already at a radiation absorbed dose of 15 Gy at the vessel surface. Following a surface dosage of 45 Gy the proliferative response to the vessel injury is almost completely abolished.
KEYWORDS Angioplasty; Arteries; Coronary disease; Remodeling; Restenosis