Sustained Attenuation of Neointimal Coverage Over the Stent Following Brachytherapy for In-Stent Restenosis Angioscopic Findings

Abstract

The nature of the vessel lumen following vascular brachytherapy (VBT) has not been extensively explored in the clinical setting. By using angioscopy, 33 stents treated with percutaneous balloon angioplasty with or without VBT for in-stent restenosis after 8.9 +/- 2.1 months of the treatment were followed (VBT =14 lesions; control =19 lesions). Neointimal coverage, stent attachment, and the presence of red or white thrombi were factors that were assessed. The majority of the stents (74%) were fully covered with non-transparent neointima in the control group. In contrast, stent struts were clearly seen in 57% lesions with VBT. The absence of neointima with glittering stent struts were only seen in 29% of lesions in VBT (p = 0.03). Incomplete stent attachment was not detected in the controls, whereas 14% were in VBT (p = 0.17). Red thrombi were observed in 14% with VBT and in 16% in controls, which showed that there was a similar incidence regardless of the treatment. Neither exposure of stent struts (p = 0.5) nor incomplete stent attachment (p = 1.0) was related to thrombi. The exposure of stent struts and incomplete stent attachment were occasionally observed by angioscopy even 9 months after VBT for the treatment of in-stent restenosis.