Endovascular irradiation with the liquid beta-emitter Rhenium-188 to reduce restenosis after experimental wall injury.
OBJECTIVE
Postinterventional irradiation is a new therapeutic concept in the prevention of restenosis. The liquid beta-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 mm(2) [0.33 mm(2), 0.75 mm(2)] vs. 0.49 mm(2) [0.34 mm(2), 0.66 mm(2)]), neointimal hyperplasia was decreased significantly at 15 Gy (0.15 mm(2) [0.04 mm(2), 0.17 mm(2)]) and 30 Gy (0.07 mm(2) [0.04 mm(2), 0. 10 mm(2)]), and completely inhibited at the highest dosages (45 Gy: 0 mm(2) [0 mm(2), 0.04 mm(2)]; 60 Gy: 0 mm(2) [0 mm(2), 0.01 mm(2)]).


CONCLUSIONS
Catheter transmitted endovascular irradiation with the liquid beta-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.
Wohlfrom
M
M
Department of Internal Medicine II, Cardiology, University of Ulm, Robert-Koch-Strasse 8, D-89081, Ulm, Germany. markus.wohlfrom@medizin.uni-ulm.de
Kotzerke
J
J
Kamenz
J
J
Eble
M
M
Hess
B
B
Wöhrle
J
J
Reske
S N
SN
Hombach
V
V
Hanke
H
H
Höher
M
M
D000800:Angioplasty, Balloon / Q000379:methods*; D000818:Animals; D001918:Brachytherapy / Q000379:methods*; D017536:Carotid Artery, Common / Q000473:pathology; D016893:Carotid Stenosis / Q000473:pathology / Q000517:prevention & control* / Q000628:therapy; D005240:Feasibility Studies; D008297:Male; D011817:Rabbits; D011868:Radioisotopes / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D012008:Recurrence; D012211:Rhenium / Q000627:therapeutic use*; D017539:Tunica Intima / Q000473:pathology
D011868:Radioisotopes; D012211:Rhenium