Effects of beta(-)-emitting (188)Re balloon in stented porcine coronary arteries: an angiographic, intravascular ultrasound, and histomorphometric study.
BACKGROUND
Restenosis within stents may be prevented by ionizing radiation from an intravascular source.


RESULTS
A liquid beta(-) radiation ((188)Re) balloon was evaluated in a randomized and blinded porcine coronary model of stent restenosis. Group A pigs (n=17) received 0,16, 22, or 29 Gy at 0.5-mm depth, followed by stenting. Restenosis was quantified by angiography, ultrasound, and histomorphometry at 30 days. Group B (n=7) was stented first and then treated with 0 or 29 Gy with follow-up at 60 days. There was a measurable effect at 16 Gy, which improved with increasing doses. At 29 Gy, the histological stenotic area was reduced by 67% (22% versus 66% in controls, P<0.001). Radiation after stenting was equally effective; the stenotic area was reduced (21% versus 65%, P<0.001). At 16 Gy, the vessel just distal to the stent was significantly smaller than control vessels because of intimal thickening (P=0.003). Radiated vessels had distinctive histology consisting of neointimal fibrin and reduced smooth muscle cells and matrix (P<0.0001).


CONCLUSIONS
(188)Re balloon brachytherapy in porcine coronary arteries results in dose-dependent and injury-independent inhibition of stent restenosis for up to 60 days. Restenosis at the borders of the irradiated zone is a potential limitation and may be related to underdosing. Brachytherapy with the (188)Re balloon appears to be safe and feasible for clinical studies.
Makkar
R
R
Division of Cardiology and the Research Institute at Cedars-Sinai Medical Center and the UCLA School of Medicine, Los Angeles, CA, USA.
Whiting
J
J
Li
A
A
Honda
H
H
Fishbein
M C
MC
Knapp
F F
FF
Hausleiter
J
J
Litvack
F
F
Eigler
N L
NL
D015906:Angioplasty, Balloon, Coronary; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D001610:Beta Particles; D019917:Blood Vessel Prosthesis Implantation; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects*; D011839:Radiation, Ionizing; D011868:Radioisotopes; D011897:Random Allocation; D012008:Recurrence; D012211:Rhenium; D015607:Stents; D013552:Swine; D014463:Ultrasonography
D011868:Radioisotopes; D012211:Rhenium