Ultrasonic characteristics and histopathologic comparison of vascular remodeling after carotid balloon injury in rats / 中华超声影像学杂志

ABSTRACT

Objective:To detect the characteristics of vascular remodeling after carotid balloon injury model in rats using ultrasound biomicroscopy(UBM), and to discuss the application value of UBM technique by comparing ultrasonic characteristics with histopathological results.Methods:Carotid balloon injury was performed in 10-week-old SD rats(11 female and 11 male) by 2F Fogarty balloon catheter. The left common carotid artery(CCA) was injured and the right side in the same animal was used as an uninjured control. Arterial structures and hemodynamics were evaluated pre-procedure and post-procedure at 7, 14 days.The intima-media thickness(IMT) inner diameter, outer diameter, lumen area, vessel area, peak systolic velocity, end diastolic velocity of CCA were measured by UBM, and the vascular resistance index, shear stress and blood flow were calculated to evaluate the vascular hemodynamics. The histological data were obtained by H&E staining in cross-sections at 14 days after balloon injury. The characteristics of arterial structure and hemodynamic changes at various time points were compared, the structural changes of CCA between injured and control side after injury were compared. The Spearman correlation and linear regression were used to test the correlation between ultrasonic and histological measurements 14 days after balloon injury.Results:①Compared with pre-procedure, the IMT at 14 days after balloon injury was increased, the inner diameter was decreased, the shear stress in ultrasound was increased(all P<0.05). H&E staining histological test showed that IMT and neointima area in male rats were larger than those of female rats (all P<0.001). ②After carotid balloon injury, the lumen area decreased, but the CCA underwent compensatory positive remodeling and the vessel area increased. ③Significant correlations were demonstrated between UBM and histology in IMT, inner diameter, outer diameter and vessel area of CCA( rs=0.819, 0.965, 0.896, 0.955; all P<0.001). The vessel area value measured by UBM was larger than that of histology( P=0.006). Conclusions:The CCA of rats can be showed clearly by UBM in males and females. The arterial structure cab be measured by UBM accurately with good correlation with histology, as did arterial hemodynamic parameters, which may be benefit for the study in carotid balloon injury model of rats.