The process of in-stent restenosis evaluated by intravascular ultrasound

Objective The purpose of this study was to assess the in stent restenotic process by intravascular ultrasound. Method Fifty patients with 65 stents underwent intravascular ultrasound imaging at the time of 10 months after implantation. There were of 26 stents with and 39 stents without in stent restenosis. The lumen and intimal hyperplasia cross sectional areas (CSA) within the stents were measured by intravascular ultrasound. Pattern of in stent restenosis were then identified. Results Restenotic stents had smaller minimal lumen CSA [(2.5±1.2) mm 2 vs(5.2±1.4) mm 2 P 0.001)]and minimal stent CSA[(4.2±1.8) mm 2 vs.(6.8±1.7) mm 2, P 0.01)] than those of nonrestenotic stents. But intimal hyperplasia had no significant difference between restenotic and nonrestenotic stents[(1.7±1.0) mm 2 vs(1.5±0.9) mm 2 P =0.65)]. The stent restenosis was more commonly focal in nature 69.2%. Conclusion The degree of stent dilation was important in the development of in stent restenosis. But the intimal hyperplasia had no significant difference between restenotic and non restenotic stents in this study.