Acute lumen overdilation improves outcome after brachytherapy of in-stent restenosis☆

Abstract 

Background

The aim of our study was to test the impact of acute lumen overdilation on neointimal hyperplasia and late lumen size after vascular brachytherapy for in-stent restenosis (ISR).

Methods

Forty-seven ISR lesions located in 47 coronary arteries in 44 consecutive patients underwent beta brachytherapy with serial intravascular ultrasound studies. Vessel, lumen, and stent cross-sectional area were measured at 1-mm steps. Based on an interpolated reference cross-sectional area, each cross section was assessed as overdilated (lumen cross-sectional area >interpolated reference cross-sectional area) or not overdilated (lumen cross-sectional area <interpolated reference cross-sectional area).

Results

Overall, 502 sections were overdilated and 673 sections were not. Overdilated sections had a larger final lumen cross-sectional area (8.02±1.98 vs. 6.90±2.23 mm², P<.001) and more recurrent neointimal hyperplasia (1.59±2.17 vs. 0.31±1.79 mm², P<.001), but a smaller follow-up area stenosis (−1.03±32.99% vs. 22.15±20.75%, P<.001). This was especially true in smaller arteries (angiographic reference <3.0 mm) where larger follow-up lumen cross-sectional area and a corresponding smaller area stenosis were present (5.38±1.98 vs. 4.84±1.88 mm² and 6.90±31.57% vs. 28.61±21.86%, P<.01 and P<.001, respectively).

Conclusions

Especially in small arteries, the strategy of acute lumen overdilation during balloon angioplasty prior to beta vascular brachytherapy treatment of ISR lesions has a favorable long-term result.

Keywords: In-stent restenosis, Lumen overdilatation, Vascular brachytherapy, Intravascular ultrasound