Effects of Endovascular Brachytherapy on the Apoptosis of Vascular Medial Smooth Muscle Cells in Rabbits after Iliac Artery Ballon-overstretch Injury.

Objective To observe the effects of endovascular brachytherapy on the apoptosis of vascular medial smooth muscle cell ( SMC) and the dose-effect relation . To discuss the possible mechanisms of radiation in the prevention of vascular restenosis (RS) in rabbits after iliac artery balloon-overstretch injury. Methods Twenty-four rabbits were randomly divided into four groups. One sides iliac artery were given a radiation dose of 9.1, 21. 8 and 33.4Gy 32P respectively compared with the other sides. Rabbits were killed on the 5th week after operation. Apoptosis was examined using terminal deoxynucleotidyl transferase-media-ted deoxyuridine triphosphate nick-end labeling (TUNEL). Results Compared with the control group, the degree of restenosis was not statistical difference in 9. 1 Gy group and was slight in 21. 8 Gy group,was high in 33.4 Gy group. The apoptosis rate in 21. 8 Gy and 33.4 Gy groups was higher than that in control group. The effect was much more evident in 21. 8 Gy group. Conclusion Endovascular brachytherapy with 32P filled ballon catheter system could prevent restenosis after angioplasty . Inducing SMC apoptosis may contribute to the preventing of restenosis.