Labinaz M, Pels K, Hoffert C, Aggarwal S, O'Brien E R
Department of Medicine, University of Ottawa Heart Institute, Ontario, Canada.
Cardiovasc Res. 1999 Jan;41(1):255-66. doi: 10.1016/s0008-6363(98)00203-x.
Arterial remodeling has been suggested as the predominant factor in restenosis. However, the time course and morphometric factors that determine whether remodeling occurs remain unclear. We hypothesized that arterial remodeling does not occur in all arteries following balloon injury and is dependent on neoadventitial formation.
Using single (SI) and double (DI) balloon injury of Yorkshire porcine coronary arteries we examined changes in morphometry 3, 7, 14, 28 days following balloon injury.
In both SI and DI arteries, the neoadventitia (NAD) area expanded by day 3 and was the first compartment to increase following injury. In SI arteries lumen area (LA) decreased between day 3 and 14 while in DI arteries, there was significantly less loss in LA. In SI arteries, contracture of the area circumscribed by the external elastic lamina (EEL), which occurred predominantly between day 7 and 14, accounted for 67% of the loss of LA.
Accumulation of NAD appears to be the earliest change in the vessel wall following balloon injury of normal or previously injured arteries and precedes the growth of the I + M (intima and media). The predominant mechanism for lumenal narrowing following single balloon injury of a normal artery is remodeling. In contrast, remodeling does not occur in DI arteries, possibly due to differences in the degree of adventitial fibrosis of normal and injured arteries.
动脉重塑被认为是再狭窄的主要因素。然而，决定重塑是否发生的时间进程和形态学因素仍不清楚。我们假设并非所有动脉在球囊损伤后都会发生重塑，且其依赖于新生外膜的形成。
使用约克郡猪冠状动脉的单次（SI）和双次（DI）球囊损伤，我们在球囊损伤后3、7、14、28天检查了形态学变化。
在SI和DI动脉中，新生外膜（NAD）面积在第3天就开始扩大，是损伤后第一个增加的部分。在SI动脉中，管腔面积（LA）在第3天至14天之间减小，而在DI动脉中，LA的损失明显较少。在SI动脉中，主要发生在第7天至14天之间的外弹性膜（EEL）所包围区域的挛缩，占LA损失的67%。
NAD的积累似乎是正常或先前损伤的动脉球囊损伤后血管壁最早的变化，且先于内膜和中膜（I + M）的生长。正常动脉单次球囊损伤后管腔狭窄的主要机制是重塑。相比之下，DI动脉中不发生重塑，这可能是由于正常和损伤动脉外膜纤维化程度的差异。
